Provided by: libvm-ec2-perl_1.23-1_all bug

NAME

       VM::EC2 - Control the Amazon EC2 and Eucalyptus Clouds

SYNOPSIS

        # set environment variables EC2_ACCESS_KEY, EC2_SECRET_KEY and/or EC2_URL
        # to fill in arguments automatically

        ## IMAGE AND INSTANCE MANAGEMENT
        # get new EC2 object
        my $ec2 = VM::EC2->new(-access_key => 'access key id',
                               -secret_key => 'aws_secret_key',
                               -endpoint   => 'http://ec2.amazonaws.com');

        # fetch an image by its ID
        my $image = $ec2->describe_images('ami-12345');

        # get some information about the image
        my $architecture = $image->architecture;
        my $description  = $image->description;
        my @devices      = $image->blockDeviceMapping;
        for my $d (@devices) {
           print $d->deviceName,"\n";
           print $d->snapshotId,"\n";
           print $d->volumeSize,"\n";
        }

        # run two instances
        my @instances = $image->run_instances(-key_name      =>'My_key',
                                              -security_group=>'default',
                                              -min_count     =>2,
                                              -instance_type => 't1.micro')
                  or die $ec2->error_str;

        # wait for both instances to reach "running" or other terminal state
        $ec2->wait_for_instances(@instances);

        # print out both instance's current state and DNS name
        for my $i (@instances) {
           my $status = $i->current_status;
           my $dns    = $i->dnsName;
           print "$i: [$status] $dns\n";
        }

        # tag both instances with Role "server"
        foreach (@instances) {$_->add_tag(Role=>'server');

        # stop both instances
        foreach (@instances) {$_->stop}

        # find instances tagged with Role=Server that are
        # stopped, change the user data and restart.
        @instances = $ec2->describe_instances({'tag:Role'       => 'Server',
                                               'instance-state-name' => 'stopped'});
        for my $i (@instances) {
           $i->userData('Secure-mode: off');
           $i->start or warn "Couldn't start $i: ",$i->error_str;
        }

        # create an image from both instance, tag them, and make
        # them public
        for my $i (@instances) {
            my $img = $i->create_image("Autoimage from $i","Test image");
            $img->add_tags(Name  => "Autoimage from $i",
                           Role  => 'Server',
                           Status=> 'Production');
            $img->make_public(1);
        }

        ## KEY MANAGEMENT

        # retrieve the name and fingerprint of the first instance's
        # key pair
        my $kp = $instances[0]->keyPair;
        print $instances[0], ": keypair $kp=",$kp->fingerprint,"\n";

        # create a new key pair
        $kp = $ec2->create_key_pair('My Key');

        # get the private key from this key pair and write it to a disk file
        # in ssh-compatible format
        my $private_key = $kp->private_key;
        open (my $f,'>MyKeypair.rsa') or die $!;
        print $f $private_key;
        close $f;

        # Import a preexisting SSH key
        my $public_key = 'ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC8o...';
        $key = $ec2->import_key_pair('NewKey',$public_key);

        ## SECURITY GROUPS AND FIREWALL RULES
        # Create a new security group
        my $group = $ec2->create_security_group(-name        => 'NewGroup',
                                                -description => 'example');

        # Add a firewall rule
        $group->authorize_incoming(-protocol  => 'tcp',
                                   -port      => 80,
                                   -source_ip => ['192.168.2.0/24','192.168.2.1/24'});

        # Write rules back to Amazon
        $group->update;

        # Print current firewall rules
        print join ("\n",$group->ipPermissions),"\n";

        ## VOLUME && SNAPSHOT MANAGEMENT

        # find existing volumes that are available
        my @volumes = $ec2->describe_volumes({status=>'available'});

        # back 'em all up to snapshots
        foreach (@volumes) {$_->snapshot('Backup on '.localtime)}

        # find a stopped instance in first volume's availability zone and
        # attach the volume to the instance using /dev/sdg
        my $vol  = $volumes[0];
        my $zone = $vol->availabilityZone;
        @instances = $ec2->describe_instances({'availability-zone'=> $zone,
                                               'run-state-name'   => $stopped);
        $instances[0]->attach_volume($vol=>'/dev/sdg') if @instances;

        # create a new 20 gig volume
        $vol = $ec2->create_volume(-availability_zone=> 'us-east-1a',
                                   -size             =>  20);
        $ec2->wait_for_volumes($vol);
        print "Volume $vol is ready!\n" if $vol->current_status eq 'available';

        # create a new elastic address and associate it with an instance
        my $address = $ec2->allocate_address();
        $instances[0]->associate_address($address);

DESCRIPTION

       This is an interface to the 2012-12-01 version of the Amazon AWS API
       (http://aws.amazon.com/ec2). It was written provide access to the new tag and metadata
       interface that is not currently supported by Net::Amazon::EC2, as well as to provide
       developers with an extension mechanism for the API. This library will also support the
       Eucalyptus open source cloud (http://open.eucalyptus.com).

       The main interface is the VM::EC2 object, which provides methods for interrogating the
       Amazon EC2, launching instances, and managing instance lifecycle. These methods return the
       following major object classes which act as specialized interfaces to AWS:

        VM::EC2::BlockDevice               -- A block device
        VM::EC2::BlockDevice::Attachment   -- Attachment of a block device to an EC2 instance
        VM::EC2::BlockDevice::EBS          -- An elastic block device
        VM::EC2::BlockDevice::Mapping      -- Mapping of a virtual storage device to a block device
        VM::EC2::BlockDevice::Mapping::EBS -- Mapping of a virtual storage device to an EBS block device
        VM::EC2::Group                     -- Security groups
        VM::EC2::Image                     -- Amazon Machine Images (AMIs)
        VM::EC2::Instance                  -- Virtual machine instances
        VM::EC2::Instance::Metadata        -- Access to runtime metadata from running instances
        VM::EC2::Region                    -- Availability regions
        VM::EC2::Snapshot                  -- EBS snapshots
        VM::EC2::Tag                       -- Metadata tags

       In addition, there is a high level interface for interacting with EC2 servers and volumes,
       including file transfer and remote shell facilities:

         VM::EC2::Staging::Manager         -- Manage a set of servers and volumes.
         VM::EC2::Staging::Server          -- A staging server, with remote shell and file transfer
                                               facilities.
         VM::EC2::Staging::Volume          -- A staging volume with the ability to copy itself between
                                               availability zones and regions.

       and a few specialty classes:

         VM::EC2::Security::Token          -- Temporary security tokens for granting EC2 access to
                                               non-AWS account holders.
         VM::EC2::Security::Credentials    -- Credentials for use by temporary account holders.
         VM::EC2::Security::Policy         -- Policies that restrict what temporary account holders
                                               can do with EC2 resources.
         VM::EC2::Security::FederatedUser  -- Account name information for temporary account holders.

       Lastly, there are several utility classes:

        VM::EC2::Generic                   -- Base class for all AWS objects
        VM::EC2::Error                     -- Error messages
        VM::EC2::Dispatch                  -- Maps AWS XML responses onto perl object classes
        VM::EC2::ReservationSet            -- Hidden class used for describe_instances() request;
                                               The reservation Ids are copied into the Instance
                                                object.

       There is also a high-level API called "VM::EC2::Staging::Manager" for managing groups of
       staging servers and volumes which greatly simplifies the task of creating and updating
       instances that mount multiple volumes. The API also provides a one-line command for
       migrating EBS-backed AMIs from one zone to another. See VM::EC2::Staging::Manager.

       The interface provided by these modules is based on that described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/. The following caveats
       apply:

        1) Not all of the Amazon API is currently implemented. Specifically,
           a handful calls dealing with cluster management and VM importing
           are missing.  See L</MISSING METHODS> for a list of all the
           unimplemented API calls. Volunteers to fill in these gaps are
           most welcome!

        2) For consistency with common Perl coding practices, method calls
           are lowercase and words in long method names are separated by
           underscores. The Amazon API prefers mixed case.  So in the Amazon
           API the call to fetch instance information is "DescribeInstances",
           while in VM::EC2, the method is "describe_instances". To avoid
           annoyance, if you use the mixed case form for a method name, the
           Perl autoloader will automatically translate it to underscores for
           you, and vice-versa; this means you can call either
           $ec2->describe_instances() or $ec2->DescribeInstances().

        3) Named arguments passed to methods are all lowercase, use
           underscores to separate words and start with hyphens.
           In other words, if the AWS API calls for an argument named
           "InstanceId" to be passed to the "DescribeInstances" call, then
           the corresponding Perl function will look like:

                $instance = $ec2->describe_instances(-instance_id=>'i-12345')

           In most cases automatic case translation will be performed for you
           on arguments. So in the previous example, you could use
           -InstanceId as well as -instance_id. The exception
           is when an absurdly long argument name was replaced with an
           abbreviated one as described below. In this case, you must use
           the documented argument name.

           In a small number of cases, when the parameter name was absurdly
           long, it has been abbreviated. For example, the
           "Placement.AvailabilityZone" parameter has been represented as
           -placement_zone and not -placement_availability_zone. See the
           documentation for these cases.

        4) For each of the describe_foo() methods (where "foo" is a type of
           resource such as "instance"), you can fetch the resource by using
           their IDs either with the long form:

                 $ec2->describe_foo(-foo_id=>['a','b','c']),

           or a shortcut form:

                 $ec2->describe_foo('a','b','c');

           Both forms are listed in the headings in the documentation.

        5) When the API calls for a list of arguments named Arg.1, Arg.2,
           then the Perl interface allows you to use an anonymous array for
           the consecutive values. For example to call describe_instances()
           with multiple instance IDs, use:

              @i = $ec2->describe_instances(-instance_id=>['i-12345','i-87654'])

        6) All Filter arguments are represented as a -filter argument whose value is
           an anonymous hash:

              @i = $ec2->describe_instances(-filter=>{architecture=>'i386',
                                                      'tag:Name'  =>'WebServer'})

           If there are no other arguments you wish to pass, you can omit the
           -filter argument and just pass a hashref:

              @i = $ec2->describe_instances({architecture=>'i386',
                                             'tag:Name'  =>'WebServer'})

           For any filter, you may represent multiple OR arguments as an arrayref:

             @i = $ec2->describe-instances({'instance-state-name'=>['stopped','terminated']})

           When adding or removing tags, the -tag argument uses the same syntax.

        7) The tagnames of each XML object returned from AWS are converted into methods
           with the same name and typography. So the <privateIpAddress> tag in a
           DescribeInstancesResponse, becomes:

                  $instance->privateIpAddress

           You can also use the more Perlish form -- this is equivalent:

                 $instance->private_ip_address

           Methods that correspond to complex objects in the XML hierarchy
           return the appropriate Perl object. For example, an instance's
           blockDeviceMapping() method returns an object of type
           VM::EC2::BlockDevice::Mapping.

           All objects have a fields() method that will return the XML
           tagnames listed in the AWS specifications.

             @fields = sort $instance->fields;
             # 'amiLaunchIndex', 'architecture', 'blockDeviceMapping', ...

        8) Whenever an object has a unique ID, string overloading is used so that
           the object interpolates the ID into the string. For example, when you
           print a VM::EC2::Volume object, or use it in another string context,
           then it will appear as the string "vol-123456". Nevertheless, it will
           continue to be usable for method calls.

                ($v) = $ec2->describe_volumes();
                print $v,"\n";                 # prints as "vol-123456"
                $zone = $v->availabilityZone;  # acts like an object

        9) Many objects have convenience methods that invoke the AWS API on your
           behalf. For example, instance objects have a current_status() method that returns
           the run status of the object, as well as start(), stop() and terminate()
           methods that control the instance's lifecycle.

                if ($instance->current_status eq 'running') {
                    $instance->stop;
                }

        10) Calls to AWS that have failed for one reason or another (invalid
           arguments, communications problems, service interruptions) will
           return undef and set the VM::EC2->is_error() method to true. The
           error message and its code can then be recovered by calling
           VM::EC2->error.

             $i = $ec2->describe_instance('i-123456');
             unless ($i) {
                 warn 'Got no instance. Message was: ',$ec2->error;
             }

           You may also elect to raise an exception when an error occurs.
           See the new() method for details.

EXAMPLE SCRIPT

       The script sync_to_snapshot.pl, distributed with this module, illustrates a relatively
       complex set of steps on EC2 that does something useful. Given a list of directories or
       files on the local filesystem it copies the files into an EBS snapshot with the desired
       name by executing the following steps:

       1. Provisions a new EBS volume on EC2 large enough to hold the data.

       2. Spins up a staging instance to manage the network transfer of data from the local
       machine to the staging volume.

       3. Creates a temporary ssh keypair and a security group that allows an rsync-over-ssh.

       4. Formats and mounts the volume if necessary.

       5. Initiates an rsync-over-ssh for the designated files and directories.

       6. Unmounts and snapshots the volume.

       7. Cleans up.

       If a snapshot of the same name already exists, then it is used to create the staging
       volume, enabling network-efficient synchronization of the files. A snapshot tag named
       "Version" is incremented each time you synchronize.

CORE METHODS

       This section describes the VM::EC2 constructor, accessor methods, and methods relevant to
       error handling.

   $ec2 = VM::EC2->new(-access_key=>$id,-secret_key=>$key,-endpoint=>$url)
       Create a new Amazon access object. Required arguments are:

        -access_key   Access ID for an authorized user

        -secret_key   Secret key corresponding to the Access ID

        -security_token Temporary security token obtained through a call to the
                      AWS Security Token Service

        -endpoint     The URL for making API requests

        -region       The region to receive the API requests

        -raise_error  If true, throw an exception.

        -print_error  If true, print errors to STDERR.

       One or more of -access_key or -secret_key can be omitted if the environment variables
       EC2_ACCESS_KEY and EC2_SECRET_KEY are defined. If no endpoint is specified, then the
       environment variable EC2_URL is consulted; otherwise the generic endpoint
       http://ec2.amazonaws.com/ is used. You can also select the endpoint by specifying one of
       the Amazon regions, such as "us-west-2", with the -region argument. The endpoint specified
       by -region will override -endpoint.

       -security_token is used in conjunction with temporary security tokens returned by
       $ec2->get_federation_token() and $ec2->get_session_token() to grant restricted, time-
       limited access to some or all your EC2 resources to users who do not have access to your
       account. If you pass either a VM::EC2::Security::Token object, or the
       VM::EC2::Security::Credentials object contained within the token object, then new() does
       not need the -access_key or -secret_key arguments. You may also pass a session token
       string scalar to -security_token, in which case you must also pass the access key ID and
       secret keys generated at the same time the session token was created. See
       http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/UsingIAM.html and "AWS SECURITY
       TOKENS".

       To use a Eucalyptus cloud, please provide the appropriate endpoint URL.

       By default, when the Amazon API reports an error, such as attempting to perform an invalid
       operation on an instance, the corresponding method will return empty and the error message
       can be recovered from $ec2->error(). However, if you pass -raise_error=>1 to new(), the
       module will instead raise a fatal error, which you can trap with eval{} and report with
       $@:

         eval {
            $ec2->some_dangerous_operation();
            $ec2->another_dangerous_operation();
         };
         print STDERR "something bad happened: $@" if $@;

       The error object can be retrieved with $ec2->error() as before.

   $access_key = $ec2->access_key([$new_access_key])
       Get or set the ACCESS KEY. In this and all similar get/set methods, call the method with
       no arguments to get the current value, and with a single argument to change the value:

        $current_key = $ec2->access_key;
        $ec2->access_key('XYZZY');

       In the case of setting the value, these methods will return the old value as their result:

        $old_key = $ec2->access_key($new_key);

   $secret = $ec2->secret([$new_secret])
       Get or set the SECRET KEY

   $secret = $ec2->security_token([$new_token])
       Get or set the temporary security token. See "AWS SECURITY TOKENS".

   $endpoint = $ec2->endpoint([$new_endpoint])
       Get or set the ENDPOINT URL.

   $region = $ec2->region([$new_region])
       Get or set the EC2 region manipulated by this module. This has the side effect of changing
       the endpoint.

   $ec2->raise_error($boolean)
       Change the handling of error conditions. Pass a true value to cause Amazon API errors to
       raise a fatal error. Pass false to make methods return undef. In either case, you can
       detect the error condition by calling is_error() and fetch the error message using
       error(). This method will also return the current state of the raise error flag.

   $ec2->print_error($boolean)
       Change the handling of error conditions. Pass a true value to cause Amazon API errors to
       print error messages to STDERR. Pass false to cancel this behavior.

   $boolean = $ec2->is_error
       If a method fails, it will return undef. However, some methods, such as describe_images(),
       will also return undef if no resources matches your search criteria. Call is_error() to
       distinguish the two eventualities:

         @images = $ec2->describe_images(-owner=>'29731912785');
         unless (@images) {
             die "Error: ",$ec2->error if $ec2->is_error;
             print "No appropriate images found\n";
         }

   $err = $ec2->error
       If the most recently-executed method failed, $ec2->error() will return the error code and
       other descriptive information. This method will return undef if the most recently executed
       method was successful.

       The returned object is actually an AWS::Error object, which has two methods named code()
       and message(). If used in a string context, its operator overloading returns the composite
       string "$message [$code]".

   $err = $ec2->error_str
       Same as error() except it returns the string representation, not the object. This works
       better in debuggers and exception handlers.

   $account_id = $ec2->account_id
       Looks up the account ID corresponding to the credentials provided when the VM::EC2
       instance was created. The way this is done is to fetch the "default" security group, which
       is guaranteed to exist, and then return its groupId field. The result is cached so that
       subsequent accesses are fast.

   $account_id = $ec2->userId
       Same as above, for convenience.

   $new_ec2 = $ec2->clone
       This method creates an identical copy of the EC2 object. It is used occasionally
       internally for creating an EC2 object in a different AWS region:

        $singapore = $ec2->clone;
        $singapore->region('ap-souteast-1');

EC2 REGIONS AND AVAILABILITY ZONES

       This section describes methods that allow you to fetch information on EC2 regions and
       availability zones. These methods return objects of type VM::EC2::Region and
       VM::EC2::AvailabilityZone.

   @regions = $ec2->describe_regions(@list)
   @regions = $ec2->describe_regions(-region_name=>\@list)
       Describe regions and return a list of VM::EC2::Region objects. Call with no arguments to
       return all regions. You may provide a list of regions in either of the two forms shown
       above in order to restrict the list returned. Glob-style wildcards, such as "*east") are
       allowed.

   describe_availability_zones(@names)
       @zones = $ec2->describe_availability_zones(@names)

   describe_availability_zones(-zone_name=>\@names,-filter=>\%filters)
       @zones = $ec2->describe_availability_zones(-zone_name=>\@names,-filter=>\%filters)

       Describe availability zones and return a list of VM::EC2::AvailabilityZone objects. Call
       with no arguments to return all availability regions. You may provide a list of zones in
       either of the two forms shown above in order to restrict the list returned. Glob-style
       wildcards, such as "*east") are allowed.

       If you provide a single argument consisting of a hashref, it is treated as a -filter
       argument. In other words:

        $ec2->describe_availability_zones({state=>'available'})

       is equivalent to

        $ec2->describe_availability_zones(-filter=>{state=>'available'})

       Availability zone filters are described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeAvailabilityZones.html

EC2 INSTANCES

       The methods in this section allow you to retrieve information about EC2 instances, launch
       new instances, control the instance lifecycle (e.g. starting and stopping them), and
       fetching the console output from instances.

       The primary object manipulated by these methods is VM::EC2::Instance. Please see the
       VM::EC2::Instance manual page for additional methods that allow you to attach and detach
       volumes, modify an instance's attributes, and convert instances into images.

   @instances = $ec2->describe_instances(@instance_ids)
   @instances = $ec2->describe_instances(\%filters)
   @instances = $ec2->describe_instances(-instance_id=>\@ids,-filter=>\%filters)
       Return a series of VM::EC2::Instance objects. Optional arguments are:

        -instance_id     ID of the instance(s) to return information on.
                         This can be a string scalar, or an arrayref.

        -filter          Tags and other filters to apply.

       The filter argument is a hashreference in which the keys are the filter names, and the
       values are the match strings. Some filters accept wildcards.

       A typical filter example:

         $ec2->describe_instances(
           -filter        => {'block-device-mapping.device-name'=>'/dev/sdh',
                              'architecture'                    => 'i386',
                              'tag:Role'                        => 'Server'
                             });

       You may omit the -filter argument name if there are no other arguments:

         $ec2->describe_instances({'block-device-mapping.device-name'=>'/dev/sdh',
                                   'architecture'                    => 'i386',
                                    'tag:Role'                        => 'Server'});

       There are a large number of filters, which are listed in full at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeInstances.html.

       Here is a alpha-sorted list of filter names: architecture, availability-zone,
       block-device-mapping.attach-time, block-device-mapping.delete-on-termination,
       block-device-mapping.device-name, block-device-mapping.status,
       block-device-mapping.volume-id, client-token, dns-name, group-id, group-name, hypervisor,
       image-id, instance-id, instance-lifecycle, instance-state-code, instance-state-name,
       instance-type, instance.group-id, instance.group-name, ip-address, kernel-id, key-name,
       launch-index, launch-time, monitoring-state, owner-id, placement-group-name, platform,
       private-dns-name, private-ip-address, product-code, ramdisk-id, reason, requester-id,
       reservation-id, root-device-name, root-device-type, source-dest-check, spot-instance-
       request-id, state-reason-code, state-reason-message, subnet-id, tag-key, tag-value,
       tag:key, virtualization-type, vpc-id.

       Note that the objects returned from this method are the instances themselves, and not a
       reservation set. The reservation ID can be retrieved from each instance by calling its
       reservationId() method.

   @i = $ec2->run_instances($ami_id)
   @i = $ec2->run_instances(-image_id=>$id,%other_args)
       This method will provision and launch one or more instances given an AMI ID. If
       successful, the method returns a series of VM::EC2::Instance objects.

       If called with a single argument this will be interpreted as the AMI to launch, and all
       other arguments will take their defaults. Otherwise, the arguments will be taken as a
       -parameter=>$argument list.

       Required arguments:
             -image_id       ID of an AMI to launch

       Optional arguments:
             -min_count         Minimum number of instances to launch [1]

             -max_count         Maximum number of instances to launch [1]

             -key_name          Name of the keypair to use

             -security_group_id Security group ID to use for this instance.
                                Use an arrayref for multiple group IDs

             -security_group    Security group name to use for this instance.
                                Use an arrayref for multiple values.

             -user_data         User data to pass to the instances. Do NOT base64
                                encode this. It will be done for you.

             -instance_type     Type of the instance to use. See below for a
                                list.

             -availability_zone The availability zone you want to launch the
                                instance into. Call $ec2->regions for a list.

             -zone              Short version of -availability_aone.

             -placement_zone    Deprecated version of -availability_zone.

             -placement_group   An existing placement group to launch the
                                instance into. Applicable to cluster instances
                                only.

             -placement_tenancy Specify 'dedicated' to launch the instance on a
                                dedicated server. Only applicable for VPC
                                instances.

             -kernel_id         ID of the kernel to use for the instances,
                                overriding the kernel specified in the image.

             -ramdisk_id        ID of the ramdisk to use for the instances,
                                overriding the ramdisk specified in the image.

             -block_devices     Specify block devices to map onto the instances,
                                overriding the values specified in the image.
                                See below for the syntax of this argument.

             -block_device_mapping  Alias for -block_devices.

             -monitoring        Pass a true value to enable detailed monitoring.

             -subnet_id         ID of the subnet to launch the instance
                                into. Only applicable for VPC instances.

             -termination_protection  Pass true to lock the instance so that it
                                cannot be terminated using the API. Use
                                modify_instance() to unset this if youu wish to
                                terminate the instance later.

             -disable_api_termination -- Same as above.

             -shutdown_behavior Pass "stop" (the default) to stop the instance
                                and save its disk state when "shutdown" is called
                                from within the instance. Stopped instances can
                                be restarted later. Pass "terminate" to
                                instead terminate the instance and discard its
                                state completely.

             -instance_initiated_shutdown_behavior -- Same as above.

             -private_ip_address Assign the instance to a specific IP address
                                from a VPC subnet (VPC only).

             -client_token      Unique identifier that you can provide to ensure
                                idempotency of the request. You can use
                                $ec2->token() to generate a suitable identifier.
                                See http://docs.amazonwebservices.com/AWSEC2/
                                    latest/UserGuide/Run_Instance_Idempotency.html

             -network_interfaces  A single network interface specification string
                                or a list of them as an array reference (VPC only).
                                These are described in more detail below.

             -iam_arn           The Amazon resource name (ARN) of the IAM Instance Profile (IIP)
                                  to associate with the instances.

             -iam_name          The name of the IAM instance profile (IIP) to associate with the
                                  instances.

             -ebs_optimized     Boolean. If true, create an EBS-optimized instance
                                (valid only for certain instance types.

       Instance types
           The following is the list of instance types currently allowed by Amazon:

              m1.small   c1.medium  m2.xlarge   cc1.4xlarge  cg1.4xlarge  t1.micro
              m1.large   c1.xlarge  m2.2xlarge
              m1.xlarge             m2.4xlarge

       Block device syntax
           The syntax of -block_devices is identical to what is used by the ec2-run-instances
           command-line tool. Borrowing from the manual page of that tool:

           The format is '<device>=<block-device>', where 'block-device' can be one of the
           following:

               - 'none': indicates that a block device that would be exposed at the
                  specified device should be suppressed. For example: '/dev/sdb=none'

                - 'ephemeral[0-3]': indicates that the Amazon EC2 ephemeral store
                  (instance local storage) should be exposed at the specified device.
                  For example: '/dev/sdc=ephemeral0'.

                - 'vol-12345678': A volume ID will attempt to attach the given volume to the
                  instance, contingent on volume state and availability zone.

                - 'none': Suppress this block device, even if it is mapped in the AMI.

                - '[<snapshot-id>][:<size>[:<delete-on-termination>[:<volume-type>[:<iops>]]]]':
                  indicates that an Amazon EBS volume, created from the specified Amazon EBS
                  snapshot, should be exposed at the specified device. The following
                  combinations are supported:

                    - '<snapshot-id>': the ID of an Amazon EBS snapshot, which must
                      be owned by or restorable by the caller. May be left out if a
                      <size> is specified, creating an empty Amazon EBS volume of
                      the specified size.

                    - '<size>': the size (GiBs) of the Amazon EBS volume to be
                      created. If a snapshot was specified, this may not be smaller
                      than the size of the snapshot itself.

                    - '<delete-on-termination>': indicates whether the Amazon EBS
                       volume should be deleted on instance termination. If not
                       specified, this will default to 'true' and the volume will be
                       deleted.

                    - '<volume-type>': The volume type. One of "standard" or "io1".

                    - '<iops>': The number of I/O operations per second (IOPS) that
                      the volume suports. A number between 100 to 2000. Only valid
                      for volumes of type "io1".

                    Examples: -block_devices => '/dev/sdb=snap-7eb96d16'
                              -block_devices => '/dev/sdc=snap-7eb96d16:80:false'
                              -block_devices => '/dev/sdd=:120'
                              -block_devices => '/dev/sdc=:120:true:io1:500'

           To provide multiple mappings, use an array reference. In this example, we launch two
           'm1.small' instance in which /dev/sdb is mapped to ephemeral storage and /dev/sdc is
           mapped to a new 100 G EBS volume:

            @i=$ec2->run_instances(-image_id  => 'ami-12345',
                                   -min_count => 2,
                                   -block_devices => ['/dev/sdb=ephemeral0',
                                                      '/dev/sdc=:100:true']
               )

       Network interface syntax
           Each instance has a single primary network interface and private IP address that is
           ordinarily automatically assigned by Amazon. When you are running VPC instances,
           however, you can add additional elastic network interfaces (ENIs) to the instance and
           add secondary private IP addresses to one or more of these ENIs. ENIs can exist
           independently of instances, and be detached and reattached in much the same way as EBS
           volumes. This is explained in detail at
           http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/using-instance-addressing.html.

           The network configuration can be specified using the -network_interface parameter:

            -network_interfaces => ['eth0=10.10.0.12:subnet-1234567:sg-1234567:true:My Custom Eth0',
                                    'eth1=10.10.1.12,10.10.1.13:subnet-999999:sg-1234567:true:My Custom Eth1',

           The format is '<device>=<specification>'. The device is an ethernet interface name
           such as eth0, eth1, eth2, etc. The specification has up to five fields, each separated
           by the ":" character. All fields are optional and can be left blank. If missing, AWS
           will choose a default.

             10.10.1.12,10.10.1.13:subnet-999999:sg-1234567:true:My Custom Eth1

           1. IP address(es): A single IP address in standard dot form, or a list of IP addresses
           separated by commas. The first address in the list will become the primary private IP
           address for the interface. Subsequent addresses will become secondary private
           addresses. You may specify "auto" or leave the field blank to have AWS choose an
           address automatically from within the subnetwork. To allocate several secondary IP
           addresses and have AWS pick the addresses automatically, give the count of secondary
           addresses you wish to allocate as an integer following the primary IP address. For
           example, "auto,3" will allocate an automatic primary IP address and three automatic
           secondary addresses, while "10.10.1.12,3" will force the primary address to be
           10.10.1.12 and create three automatic secondary addresses.

           2. Subnetwork ID: The ID of the VPC subnetwork in which the ENI resides. An instance
           may have several ENIs associated with it, and each ENI may be attached to a different
           subnetwork.

           3. Security group IDs: A comma-delimited list of the security group IDs to associate
           with this ENI.

           4. DeleteOnTerminate: True if this ENI should be automatically deleted when the
           instance terminates.

           5. Description: A human-readable description of the ENI.

           As an alternative syntax, you may specify the ID of an existing ENI in lieu of the
           primary IP address and other fields. The ENI will be attached to the instance if its
           permissions allow:

            -network_interfaces => 'eth0=eni-123456'

       Return value
           On success, this method returns a list of VM::EC2::Instance objects. If called in a
           scalar context AND only one instance was requested, it will return a single instance
           object (rather than returning a list of size one which is then converted into numeric
           "1", as would be the usual Perl behavior).

           Note that this behavior is different from the Amazon API, which returns a
           ReservationSet. In this API, ask the instances for the the reservation, owner,
           requester, and group information using reservationId(), ownerId(), requesterId() and
           groups() methods.

       Tips
           1. If you have a VM::EC2::Image object returned from
              Describe_images(), you may run it using run_instances():

            my $image = $ec2->describe_images(-image_id  => 'ami-12345');
            $image->run_instances( -min_count => 10,
                                   -block_devices => ['/dev/sdb=ephemeral0',
                                                      '/dev/sdc=:100:true']
               )

           2. It may take a short while for a newly-launched instance to be
               returned by describe_instances(). You may need to sleep for 1-2 seconds
               before current_status() returns the correct value.

           3. Each instance object has a current_status() method which will
              return the current run state of the instance. You may poll this
              method to wait until the instance is running:

              my $instance = $ec2->run_instances(...);
              sleep 1;
              while ($instance->current_status ne 'running') {
                 sleep 5;
              }

           4. The utility method wait_for_instances() will wait until all
              passed instances are in the 'running' or other terminal state.

              my @instances = $ec2->run_instances(...);
              $ec2->wait_for_instances(@instances);

   @s = $ec2->start_instances(@instance_ids)
   @s = $ec2->start_instances(-instance_id=>\@instance_ids)
       Start the instances named by @instance_ids and return one or more
       VM::EC2::Instance::State::Change objects.

       To wait for the all the instance ids to reach their final state ("running" unless an error
       occurs), call wait_for_instances().

       Example:

           # find all stopped instances
           @instances = $ec2->describe_instances(-filter=>{'instance-state-name'=>'stopped'});

           # start them
           $ec2->start_instances(@instances)

           # pause till they are running (or crashed)
           $ec2->wait_for_instances(@instances)

       You can also start an instance by calling the object's start() method:

           $instances[0]->start('wait');  # start instance and wait for it to
                                          # be running

       The objects returned by calling start_instances() indicate the current and previous states
       of the instance. The previous state is typically "stopped" and the current state is
       usually "pending." This information is only current to the time that the start_instances()
       method was called.  To get the current run state of the instance, call its status()
       method:

         die "ouch!" unless $instances[0]->current_status eq 'running';

   @s = $ec2->stop_instances(@instance_ids)
   @s = $ec2->stop_instances(-instance_id=>\@instance_ids,-force=>1)
       Stop the instances named by @instance_ids and return one or more
       VM::EC2::Instance::State::Change objects. In the named parameter version of this method,
       you may optionally provide a -force argument, which if true, forces the instance to halt
       without giving it a chance to run its shutdown procedure (the equivalent of pulling a
       physical machine's plug).

       To wait for instances to reach their final state, call wait_for_instances().

       Example:

           # find all running instances
           @instances = $ec2->describe_instances(-filter=>{'instance-state-name'=>'running'});

           # stop them immediately and wait for confirmation
           $ec2->stop_instances(-instance_id=>\@instances,-force=>1);
           $ec2->wait_for_instances(@instances);

       You can also stop an instance by calling the object's start() method:

           $instances[0]->stop('wait');  # stop first instance and wait for it to
                                         # stop completely

   @s = $ec2->terminate_instances(@instance_ids)
   @s = $ec2->terminate_instances(-instance_id=>\@instance_ids)
       Terminate the instances named by @instance_ids and return one or more
       VM::EC2::Instance::State::Change objects. This method will fail for any instances whose
       termination protection field is set.

       To wait for the all the instances to reach their final state, call wait_for_instances().

       Example:

           # find all instances tagged as "Version 0.5"
           @instances = $ec2->describe_instances({'tag:Version'=>'0.5'});

           # terminate them
           $ec2->terminate_instances(@instances);

       You can also terminate an instance by calling its terminate() method:

           $instances[0]->terminate;

   @s = $ec2->reboot_instances(@instance_ids)
   @s = $ec2->reboot_instances(-instance_id=>\@instance_ids)
       Reboot the instances named by @instance_ids and return one or more
       VM::EC2::Instance::State::Change objects.

       To wait for the all the instances to reach their final state, call wait_for_instances().

       You can also reboot an instance by calling its terminate() method:

           $instances[0]->reboot;

   $boolean = $ec2->confirm_product_instance($instance_id,$product_code)
       Return "true" if the instance indicated by $instance_id is associated with the given
       product code.

   $password_data = $ec2->get_password_data($instance_id);
   $password_data = $ec2->get_password_data(-instance_id=>$id);
       For Windows instances, get the administrator's password as a
       VM::EC2::Instance::PasswordData object.

   $output = $ec2->get_console_output(-instance_id=>'i-12345')
   $output = $ec2->get_console_output('i-12345');
       Return the console output of the indicated instance. The output is actually a
       VM::EC2::ConsoleOutput object, but it is overloaded so that when treated as a string it
       will appear as a large text string containing the  console output. When treated like an
       object it provides instanceId() and timestamp() methods.

   @monitoring_state = $ec2->monitor_instances(@list_of_instanceIds)
   @monitoring_state = $ec2->monitor_instances(-instance_id=>\@instanceIds)
       This method enables monitoring for the listed instances and returns a list of
       VM::EC2::Instance::MonitoringState objects. You can later use these objects to activate
       and inactivate monitoring.

   @monitoring_state = $ec2->unmonitor_instances(@list_of_instanceIds)
   @monitoring_state = $ec2->unmonitor_instances(-instance_id=>\@instanceIds)
       This method disables monitoring for the listed instances and returns a list of
       VM::EC2::Instance::MonitoringState objects. You can later use these objects to activate
       and inactivate monitoring.

   $meta = VM::EC2->instance_metadata
   $meta = $ec2->instance_metadata
       For use on running EC2 instances only: This method returns a VM::EC2::Instance::Metadata
       object that will return information about the currently running instance using the HTTP://
       metadata fields described at
       http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/index.html?instancedata-data-categories.html.
       This is usually fastest way to get runtime information on the current instance.

       Note that this method can be called as either an instance or a class method.

   @data = $ec2->describe_instance_attribute($instance_id,$attribute)
       This method returns instance attributes. Only one attribute can be retrieved at a time.
       The following is the list of attributes that can be retrieved:

        instanceType                      -- scalar
        kernel                            -- scalar
        ramdisk                           -- scalar
        userData                          -- scalar
        disableApiTermination             -- scalar
        instanceInitiatedShutdownBehavior -- scalar
        rootDeviceName                    -- scalar
        blockDeviceMapping                -- list of hashref
        sourceDestCheck                   -- scalar
        groupSet                          -- list of scalar

       All of these values can be retrieved more conveniently from the VM::EC2::Instance object
       returned from describe_instances(), so there is no attempt to parse the results of this
       call into Perl objects. Therefore, some of the attributes, in particular
       'blockDeviceMapping' will be returned as raw hashrefs.

   $boolean = $ec2->modify_instance_attribute($instance_id,-$attribute_name=>$value)
       This method changes instance attributes. It can only be applied to stopped instances.  The
       following is the list of attributes that can be set:

        -instance_type           -- type of instance, e.g. "m1.small"
        -kernel                  -- kernel id
        -ramdisk                 -- ramdisk id
        -user_data               -- user data
        -termination_protection  -- true to prevent termination from the console
        -disable_api_termination -- same as the above
        -shutdown_behavior       -- "stop" or "terminate"
        -instance_initiated_shutdown_behavior -- same as above
        -root_device_name        -- root device name
        -source_dest_check       -- enable NAT (VPC only)
        -group_id                -- VPC security group
        -block_devices           -- Specify block devices to change
                                    deleteOnTermination flag
        -block_device_mapping    -- Alias for -block_devices

       Only one attribute can be changed in a single request. For example:

         $ec2->modify_instance_attribute('i-12345',-kernel=>'aki-f70657b2');

       The result code is true if the attribute was successfully modified, false otherwise. In
       the latter case, $ec2->error() will provide the error message.

       The ability to change the deleteOnTermination flag for attached block devices is not
       documented in the official Amazon API documentation, but appears to work.  The syntax is:

       # turn on deleteOnTermination
        $ec2->modify_instance_attribute(-block_devices=>'/dev/sdf=v-12345') # turn off
       deleteOnTermination
        $ec2->modify_instance_attribute(-block_devices=>'/dev/sdf=v-12345')

       The syntax is slightly different from what is used by -block_devices in run_instances(),
       and is "device=volumeId:boolean". Multiple block devices can be specified using an
       arrayref.

   $boolean = $ec2->reset_instance_attribute($instance_id,$attribute)
       This method resets an attribute of the given instance to its default value. Valid
       attributes are "kernel", "ramdisk" and "sourceDestCheck". The result code is true if the
       reset was successful.

   @status_list = $ec2->describe_instance_status(@instance_ids);
   @status_list =
       $ec2->describe_instance_status(-instance_id=>\@ids,-filter=>\%filters,%other_args);
   @status_list = $ec2->describe_instance_status(\%filters);
       This method returns a list of VM::EC2::Instance::Status objects corresponding to status
       checks and scheduled maintenance events on the instances of interest. You may provide a
       list of instances to return information on, a set of filters, or both.

       The filters are described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeInstanceStatus.html.
       The brief list is:

       availability-zone, event.code, event.description, event.not-after, event.not-before,
       instance-state-name, instance-state-code, system-status.status,
       system-status.reachability, instance-status.status, instance-status.reachability.

       Request arguments are:

         -instance_id            Scalar or array ref containing the instance ID(s) to return
                                  information about (optional).

         -filter                 Filters to apply (optional).

         -include_all_instances  If true, include all instances, including those that are
                                  stopped, pending and shutting down. Otherwise, returns
                                  the status of running instances only.

        -max_results             An integer corresponding to the number of instance items
                                  per response (must be greater than 5).

       If -max_results is specified, then the call will return at most the number of instances
       you requested. You may see whether there are additional results by calling
       more_instance_status(), and then retrieve the next set of results with additional call(s)
       to describe_instance_status():

        my @results = $ec2->describe_instance_status(-max_results => 10);
        do_something(\@results);
        while ($ec2->more_instance_status) {
           @results = $ec2->describe_instance_status;
           do_something(\@results);
        }

       NOTE: As of 29 July 2012, passing -include_all_instances causes an EC2 "unknown parameter"
       error, indicating some mismatch between the documented API and the actual one.

   $t = $ec2->token
       Return a client token for use with start_instances().

Waiting for State Changes

       The methods in this section allow your script to wait in an efficient manner for desired
       state changes in instances, volumes and other objects.

   $ec2->wait_for_instances(@instances)
       Wait for all members of the provided list of instances to reach some terminal state
       ("running", "stopped" or "terminated"), and then return a hash reference that maps each
       instance ID to its final state.

       Typical usage:

        my @instances = $image->run_instances(-key_name      =>'My_key',
                                              -security_group=>'default',
                                              -min_count     =>2,
                                              -instance_type => 't1.micro')
                  or die $ec2->error_str;
        my $status = $ec2->wait_for_instances(@instances);
        my @failed = grep {$status->{$_} ne 'running'} @instances;
        print "The following failed: @failed\n";

       If no terminal state is reached within a set timeout, then this method returns undef and
       sets $ec2->error_str() to a suitable message. The timeout, which defaults to 10 minutes
       (600 seconds), can be get or set with $ec2->wait_for_timeout().

   $ec2->wait_for_snapshots(@snapshots)
       Wait for all members of the provided list of snapshots to reach some terminal state
       ("completed", "error"), and then return a hash reference that maps each snapshot ID to its
       final state.

       This method may potentially wait forever. It has no set timeout. Wrap it in an eval{} and
       set alarm() if you wish to timeout.

   $ec2->wait_for_volumes(@volumes)
       Wait for all members of the provided list of volumes to reach some terminal state
       ("available", "in-use", "deleted" or "error"), and then return a hash reference that maps
       each volume ID to its final state.

       If no terminal state is reached within a set timeout, then this method returns undef and
       sets $ec2->error_str() to a suitable message. The timeout, which defaults to 10 minutes
       (600 seconds), can be get or set with $ec2->wait_for_timeout().

   $ec2->wait_for_attachments(@attachment)
       Wait for all members of the provided list of VM::EC2::BlockDevice::Attachment objects to
       reach some terminal state ("attached" or "detached"), and then return a hash reference
       that maps each attachment to its final state.

       Typical usage:

           my $i = 0;
           my $instance = 'i-12345';
           my @attach;
           foreach (@volume) {
               push @attach,$_->attach($instance,'/dev/sdf'.$i++;
           }
           my $s = $ec2->wait_for_attachments(@attach);
           my @failed = grep($s->{$_} ne 'attached'} @attach;
           warn "did not attach: ",join ', ',@failed;

       If no terminal state is reached within a set timeout, then this method returns undef and
       sets $ec2->error_str() to a suitable message. The timeout, which defaults to 10 minutes
       (600 seconds), can be get or set with $ec2->wait_for_timeout().

   $ec2->wait_for_terminal_state(\@objects,['list','of','states'] [,$timeout])
       Generic version of the last four methods. Wait for all members of the provided list of
       Amazon objects instances to reach some terminal state listed in the second argument, and
       then return a hash reference that maps each object ID to its final state.

       If a timeout is provided, in seconds, then the method will abort after waiting the
       indicated time and return undef.

   $timeout = $ec2->wait_for_timeout([$new_timeout]);
       Get or change the timeout for wait_for_instances(), wait_for_attachments(), and
       wait_for_volumes(). The timeout is given in seconds, and defaults to 600 (10 minutes). You
       can set this to 0 to wait forever.

EC2 AMAZON MACHINE IMAGES

       The methods in this section allow you to query and manipulate Amazon machine images
       (AMIs). See VM::EC2::Image.

   @i = $ec2->describe_images(@image_ids)
   @i = $ec2->describe_images(-image_id=>\@id,-executable_by=>$id, -owner=>$id,
       -filter=>\%filters)
       Return a series of VM::EC2::Image objects, each describing an AMI. Optional arguments:

        -image_id        The id of the image, either a string scalar or an
                         arrayref.

        -executable_by   Filter by images executable by the indicated user account, or
                           one of the aliases "self" or "all".

        -owner           Filter by owner account number or one of the aliases "self",
                           "aws-marketplace", "amazon" or "all".

        -filter          Tags and other filters to apply

       If there are no other arguments, you may omit the -filter argument name and call
       describe_images() with a single hashref consisting of the search filters you wish to
       apply.

       The full list of image filters can be found at:
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeImages.html

   $image = $ec2->create_image(-instance_id=>$id,-name=>$name,%other_args)
       Create an image from an EBS-backed instance and return a VM::EC2::Image object. The
       instance must be in the "stopped" or "running" state. In the latter case, Amazon will stop
       the instance, create the image, and then restart it unless the -no_reboot argument is
       provided.

       Arguments:

        -instance_id    ID of the instance to create an image from. (required)
        -name           Name for the image that will be created. (required)
        -description    Description of the new image.
        -no_reboot      If true, don't reboot the instance.
        -block_device_mapping
                        Block device mapping as a scalar or array ref. See
                         run_instances() for the syntax.
        -block_devices  Alias of the above

   $image = $ec2->register_image(-name=>$name,%other_args)
       Register an image, creating an AMI. This can be used to create an AMI from a S3-backed
       instance-store bundle, or to create an AMI from a snapshot of an EBS-backed root volume.

       Required arguments:

        -name                 Name for the image that will be created.

       Arguments required for an EBS-backed image:

        -root_device_name     The root device name, e.g. /dev/sda1
        -block_device_mapping The block device mapping strings, including the
                              snapshot ID for the root volume. This can
                              be either a scalar string or an arrayref.
                              See run_instances() for a description of the
                              syntax.
        -block_devices        Alias of the above.

       Arguments required for an instance-store image:

        -image_location      Full path to the AMI manifest in Amazon S3 storage.

       Common optional arguments:

        -description         Description of the AMI
        -architecture        Architecture of the image ("i386" or "x86_64")
        -kernel_id           ID of the kernel to use
        -ramdisk_id          ID of the RAM disk to use

       While you do not have to specify the kernel ID, it is strongly recommended that you do so.
       Otherwise the kernel will have to be specified for run_instances().

       Note: Immediately after registering the image you can add tags to it and use
       modify_image_attribute to change launch permissions, etc.

   $result = $ec2->deregister_image($image_id)
       Deletes the registered image and returns true if successful.

   @data = $ec2->describe_image_attribute($image_id,$attribute)
       This method returns image attributes. Only one attribute can be retrieved at a time. The
       following is the list of attributes that can be retrieved:

        description            -- scalar
        kernel                 -- scalar
        ramdisk                -- scalar
        launchPermission       -- list of scalar
        productCodes           -- array
        blockDeviceMapping     -- list of hashref

       All of these values can be retrieved more conveniently from the VM::EC2::Image object
       returned from describe_images(), so there is no attempt to parse the results of this call
       into Perl objects. In particular, 'blockDeviceMapping' is returned as a raw hashrefs
       (there also seems to be an AWS bug that causes fetching this attribute to return an
       AuthFailure error).

       Please see the VM::EC2::Image launchPermissions() and blockDeviceMapping() methods for
       more convenient ways to get this data.

   $boolean = $ec2->modify_image_attribute($image_id,-$attribute_name=>$value)
       This method changes image attributes. The first argument is the image ID, and this is
       followed by the attribute name and the value to change it to.

       The following is the list of attributes that can be set:

        -launch_add_user         -- scalar or arrayref of UserIds to grant launch permissions to
        -launch_add_group        -- scalar or arrayref of Groups to remove launch permissions from
                                      (only currently valid value is "all")
        -launch_remove_user      -- scalar or arrayref of UserIds to remove from launch permissions
        -launch_remove_group     -- scalar or arrayref of Groups to remove from launch permissions
        -product_code            -- scalar or array of product codes to add
        -description             -- scalar new description

       You can abbreviate the launch permission arguments to -add_user, -add_group, -remove_user,
       -remove_group, etc.

       Only one attribute can be changed in a single request.

       For example:

         $ec2->modify_image_attribute('i-12345',-product_code=>['abcde','ghijk']);

       The result code is true if the attribute was successfully modified, false otherwise. In
       the latter case, $ec2->error() will provide the error message.

       To make an image public, specify -launch_add_group=>'all':

         $ec2->modify_image_attribute('i-12345',-launch_add_group=>'all');

       Also see VM::EC2::Image for shortcut methods. For example:

        $image->add_authorized_users(1234567,999991);

   $boolean = $ec2->reset_image_attribute($image_id,$attribute_name)
       This method resets an attribute of the given snapshot to its default value. The valid
       attributes are:

        launchPermission

EC2 VOLUMES AND SNAPSHOTS

       The methods in this section allow you to query and manipulate EC2 EBS volumes and
       snapshots. See VM::EC2::Volume and VM::EC2::Snapshot for additional functionality provided
       through the object interface.

   @v = $ec2->describe_volumes(-volume_id=>\@ids,-filter=>\%filters)
   @v = $ec2->describe_volumes(@volume_ids)
       Return a series of VM::EC2::Volume objects. Optional arguments:

        -volume_id    The id of the volume to fetch, either a string
                      scalar or an arrayref.

        -filter       One or more filters to apply to the search

       The -filter argument name can be omitted if there are no other arguments you wish to pass.

       The full list of volume filters can be found at:
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeVolumes.html

   $v = $ec2->create_volume(-availability_zone=>$zone,-snapshot_id=>$snapshotId,-size=>$size)
       Create a volume in the specified availability zone and return information about it.

       Arguments:

        -availability_zone    -- An availability zone from
                                 describe_availability_zones (required)

        -snapshot_id          -- ID of a snapshot to use to build volume from.

        -size                 -- Size of the volume, in GB (between 1 and 1024).

       One or both of -snapshot_id or -size are required. For convenience, you may abbreviate
       -availability_zone as -zone, and -snapshot_id as -snapshot.

       Optional Arguments:

        -volume_type          -- The volume type.  standard or io1, default is
                                 standard

        -iops                 -- The number of I/O operations per second (IOPS) that
                                 the volume supports.  Range is 100 to 2000.  Required
                                 when volume type is io1.

       The returned object is a VM::EC2::Volume object.

   $result = $ec2->delete_volume($volume_id);
       Deletes the specified volume. Returns a boolean indicating success of the delete
       operation. Note that a volume will remain in the "deleting" state for some time after this
       call completes.

   $attachment = $ec2->attach_volume($volume_id,$instance_id,$device);
   $attachment =
       $ec2->attach_volume(-volume_id=>$volume_id,-instance_id=>$instance_id,-device=>$device);
       Attaches the specified volume to the instance using the indicated device. All arguments
       are required:

        -volume_id      -- ID of the volume to attach. The volume must be in
                           "available" state.
        -instance_id    -- ID of the instance to attach to. Both instance and
                           attachment must be in the same availability zone.
        -device         -- How the device is exposed to the instance, e.g.
                           '/dev/sdg'.

       The result is a VM::EC2::BlockDevice::Attachment object which you can monitor by calling
       current_status():

           my $a = $ec2->attach_volume('vol-12345','i-12345','/dev/sdg');
           while ($a->current_status ne 'attached') {
              sleep 2;
           }
           print "volume is ready to go\n";

       or more simply

           my $a = $ec2->attach_volume('vol-12345','i-12345','/dev/sdg');
           $ec2->wait_for_attachments($a);

   $attachment = $ec2->detach_volume($volume_id)
   $attachment = $ec2->detach_volume(-volume_id=>$volume_id,-instance_id=>$instance_id,
       -device=>$device,      -force=>$force);
       Detaches the specified volume from an instance.

        -volume_id      -- ID of the volume to detach. (required)
        -instance_id    -- ID of the instance to detach from. (optional)
        -device         -- How the device is exposed to the instance. (optional)
        -force          -- Force detachment, even if previous attempts were
                           unsuccessful. (optional)

       The result is a VM::EC2::BlockDevice::Attachment object which you can monitor by calling
       current_status():

           my $a = $ec2->detach_volume('vol-12345');
           while ($a->current_status ne 'detached') {
              sleep 2;
           }
           print "volume is ready to go\n";

       Or more simply:

           my $a = $ec2->detach_volume('vol-12345');
           $ec2->wait_for_attachments($a);
           print "volume is ready to go\n" if $a->current_status eq 'detached';

   @v = $ec2->describe_volume_status(@volume_ids)
   @v = $ec2->describe_volume_status(\%filters)
   @v = $ec2->describe_volume_status(-volume_id=>\@ids,-filter=>\%filters)
       Return a series of VM::EC2::Volume::StatusItem objects. Optional arguments:

        -volume_id    The id of the volume to fetch, either a string
                      scalar or an arrayref.

        -filter       One or more filters to apply to the search

        -max_results  Maximum number of items to return (must be more than
                       5).

       The -filter argument name can be omitted if there are no other arguments you wish to pass.

       The full list of volume filters can be found at:
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeVolumeStatus.html

       If -max_results is specified, then the call will return at most the number of volume
       status items you requested. You may see whether there are additional results by calling
       more_volume_status(), and then retrieve the next set of results with additional call(s) to
       describe_volume_status():

        my @results = $ec2->describe_volume_status(-max_results => 10);
        do_something(\@results);
        while ($ec2->more_volume_status) {
           @results = $ec2->describe_volume_status;
           do_something(\@results);
        }

   @data = $ec2->describe_volume_attribute($volume_id,$attribute)
       This method returns volume attributes.  Only one attribute can be retrieved at a time. The
       following is the list of attributes that can be retrieved:

        autoEnableIO                      -- boolean
        productCodes                      -- list of scalar

       These values can be retrieved more conveniently from the VM::EC2::Volume object returned
       from describe_volumes():

        $volume->auto_enable_io(1);
        @codes = $volume->product_codes;

   $boolean = $ec2->enable_volume_io($volume_id)
   $boolean = $ec2->enable_volume_io(-volume_id=>$volume_id)
       Given the ID of a volume whose I/O has been disabled (e.g. due to hardware degradation),
       this method will re-enable the I/O and return true if successful.

   @snaps = $ec2->describe_snapshots(@snapshot_ids)
   @snaps = $ec2->describe_snapshots(-snapshot_id=>\@ids,%other_args)
       Returns a series of VM::EC2::Snapshot objects. All arguments are optional:

        -snapshot_id     ID of the snapshot

        -owner           Filter by owner ID

        -restorable_by   Filter by IDs of a user who is allowed to restore
                          the snapshot

        -filter          Tags and other filters

       The -filter argument name can be omitted if there are no other arguments you wish to pass.

       The full list of applicable filters can be found at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeSnapshots.html

   @data = $ec2->describe_snapshot_attribute($snapshot_id,$attribute)
       This method returns snapshot attributes. The first argument is the snapshot ID, and the
       second is the name of the attribute to fetch. Currently Amazon defines two attributes:

        createVolumePermission   -- return a list of user Ids who are
                                    allowed to create volumes from this snapshot.
        productCodes             -- product codes for this snapshot

       The result is a raw hash of attribute values. Please see VM::EC2::Snapshot for a more
       convenient way of accessing and modifying snapshot attributes.

   $boolean = $ec2->modify_snapshot_attribute($snapshot_id,-$argument=>$value)
       This method changes snapshot attributes. The first argument is the snapshot ID, and this
       is followed by an attribute modification command and the value to change it to.

       Currently the only attribute that can be changed is the createVolumeAttribute. This is
       done through the following arguments

        -createvol_add_user         -- scalar or arrayref of UserIds to grant create volume permissions to
        -createvol_add_group        -- scalar or arrayref of Groups to remove create volume permissions from
                                      (only currently valid value is "all")
        -createvol_remove_user      -- scalar or arrayref of UserIds to remove from create volume permissions
        -createvol_remove_group     -- scalar or arrayref of Groups to remove from create volume permissions

       You can abbreviate these to -add_user, -add_group, -remove_user, -remove_group, etc.

       See VM::EC2::Snapshot for more convenient methods for interrogating and modifying the
       create volume permissions.

   $boolean = $ec2->reset_snapshot_attribute($snapshot_id,$attribute)
       This method resets an attribute of the given snapshot to its default value. The only valid
       attribute at this time is "createVolumePermission."

   $snapshot = $ec2->create_snapshot($volume_id)
   $snapshot = $ec2->create_snapshot(-volume_id=>$vol,-description=>$desc)
       Snapshot the EBS volume and store it to S3 storage. To ensure a consistent snapshot, the
       volume should be unmounted prior to initiating this operation.

       Arguments:

        -volume_id    -- ID of the volume to snapshot (required)
        -description  -- A description to add to the snapshot (optional)

       The return value is a VM::EC2::Snapshot object that can be queried through its
       current_status() interface to follow the progress of the snapshot operation.

       Another way to accomplish the same thing is through the VM::EC2::Volume interface:

         my $volume = $ec2->describe_volumes(-filter=>{'tag:Name'=>'AccountingData'});
         $s = $volume->create_snapshot("Backed up at ".localtime);
         while ($s->current_status eq 'pending') {
            print "Progress: ",$s->progress,"% done\n";
         }
         print "Snapshot status: ",$s->current_status,"\n";

   $boolean = $ec2->delete_snapshot($snapshot_id)
       Delete the indicated snapshot and return true if the request was successful.

   $snapshot =
       $ec2->copy_snapshot(-source_region=>$region,-source_snapshot_id=>$id,-description=>$desc)
       Copies an existing snapshot within the same region or from one region to another.

       Required arguments:
        -region       -- The region the existing snapshot to copy resides in
        -snapshot_id  -- The snapshot ID of the snapshot to copy

       Optional arguments:
        -description  -- A description of the new snapshot

       The return value is a VM::EC2::Snapshot object that can be queried through its
       current_status() interface to follow the progress of the snapshot operation.

SECURITY GROUPS AND KEY PAIRS

       The methods in this section allow you to query and manipulate security groups (firewall
       rules) and SSH key pairs. See VM::EC2::SecurityGroup and VM::EC2::KeyPair for
       functionality that is available through these objects.

   @sg = $ec2->describe_security_groups(@group_ids)
   @sg = $ec2->describe_security_groups(%args);
   @sg = $ec2->describe_security_groups(\%filters);
       Searches for security groups (firewall rules) matching the provided filters and return a
       series of VM::EC2::SecurityGroup objects.

       In the named-argument form you can provide the following optional arguments:

        -group_name      A single group name or an arrayref containing a list
                          of names

        -name            Shorter version of -group_name

        -group_id        A single group id (i.e. 'sg-12345') or an arrayref
                          containing a list of ids

        -filter          Filter on tags and other attributes.

       The -filter argument name can be omitted if there are no other arguments you wish to pass.

       The full list of security group filters can be found at:
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeSecurityGroups.html

   $group = $ec2->create_security_group(-group_name=>$name, -group_description=>$description,
       -vpc_id     => $vpc_id )
       Create a security group. Arguments are:

        -group_name              Name of the security group (required)
        -group_description       Description of the security group (required)
        -vpc_id                  Virtual private cloud security group ID
                                  (required for VPC security groups)

       For convenience, you may use -name and -description as aliases for -group_name and
       -group_description respectively.

       If succcessful, the method returns an object of type VM::EC2::SecurityGroup.

   $boolean = $ec2->delete_security_group($group_id)
   $boolean = $ec2->delete_security_group(-group_id   => $group_id, -group_name => $name);
       Delete a security group. Arguments are:

        -group_name              Name of the security group
        -group_id                ID of the security group

       Either -group_name or -group_id is required. In the single-argument form, the method
       deletes the security group given by its id.

       If succcessful, the method returns true.

   $boolean = $ec2->update_security_group($security_group)
       Add one or more incoming firewall rules to a security group. The rules to add are stored
       in a VM::EC2::SecurityGroup which is created either by describe_security_groups() or
       create_security_group(). This method combines the actions AuthorizeSecurityGroupIngress,
       AuthorizeSecurityGroupEgress, RevokeSecurityGroupIngress, and RevokeSecurityGroupEgress.

       For details, see VM::EC2::SecurityGroup. Here is a brief summary:

        $sg = $ec2->create_security_group(-name=>'MyGroup',-description=>'Example group');

        # TCP on port 80 for the indicated address ranges
        $sg->authorize_incoming(-protocol  => 'tcp',
                                -port      => 80,
                                -source_ip => ['192.168.2.0/24','192.168.2.1/24'});

        # TCP on ports 22 and 23 from anyone
        $sg->authorize_incoming(-protocol  => 'tcp',
                                -port      => '22..23',
                                -source_ip => '0.0.0.0/0');

        # ICMP on echo (ping) port from anyone
        $sg->authorize_incoming(-protocol  => 'icmp',
                                -port      => 0,
                                -source_ip => '0.0.0.0/0');

        # TCP to port 25 (mail) from instances belonging to
        # the "Mail relay" group belonging to user 12345678.
        $sg->authorize_incoming(-protocol  => 'tcp',
                                -port      => 25,
                                -group     => '12345678/Mail relay');

        $result = $ec2->update_security_group($sg);

       or more simply:

        $result = $sg->update();

   @keys = $ec2->describe_key_pairs(@names);
   @keys = $ec2->describe_key_pairs(\%filters);
   @keys = $ec2->describe_key_pairs(-key_name => \@names, -filter    => \%filters);
       Searches for ssh key pairs matching the provided filters and return a series of
       VM::EC2::KeyPair objects.

       Optional arguments:

        -key_name      A single key name or an arrayref containing a list
                          of names

        -filter          Filter on tags and other attributes.

       The full list of key filters can be found at:
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeKeyPairs.html

   $key = $ec2->create_key_pair($name)
       Create a new key pair with the specified name (required). If the key pair already exists,
       returns undef. The contents of the new keypair, including the PEM-encoded private key, is
       contained in the returned VM::EC2::KeyPair object:

         my $key = $ec2->create_key_pair('My Keypair');
         if ($key) {
           print $key->fingerprint,"\n";
           print $key->privateKey,"\n";
         }

   $key = $ec2->import_key_pair($name,$public_key)
   $key = $ec2->import_key_pair(-key_name            => $name, -public_key_material =>
       $public_key)
       Imports a preexisting public key into AWS under the specified name.  If successful,
       returns a VM::EC2::KeyPair. The public key must be an RSA key of length 1024, 2048 or
       4096. The method can be called with two unnamed arguments consisting of the key name and
       the public key material, or in a named argument form with the following argument names:

         -key_name     -- desired name for the imported key pair (required)
         -name         -- shorter version of -key_name

         -public_key_material -- public key data (required)
         -public_key   -- shorter version of the above

       This example uses Net::SSH::Perl::Key to generate a new keypair, and then uploads the
       public key to Amazon.

         use Net::SSH::Perl::Key;

         my $newkey = Net::SSH::Perl::Key->keygen('RSA',1024);
         $newkey->write_private('.ssh/MyKeypair.rsa');  # save private parts

         my $key = $ec2->import_key_pair('My Keypair' => $newkey->dump_public)
             or die $ec2->error;
         print "My Keypair added with fingerprint ",$key->fingerprint,"\n";

       Several different formats are accepted for the key, including SSH "authorized_keys" format
       (generated by ssh-keygen and Net::SSH::Perl::Key), the SSH public keys format, and DER
       format. You do not need to base64-encode the key or perform any other pre-processing.

       Note that the algorithm used by Amazon to calculate its key fingerprints differs from the
       one used by the ssh library, so don't try to compare the key fingerprints returned by
       Amazon to the ones produced by ssh-keygen or Net::SSH::Perl::Key.

   $result = $ec2->delete_key_pair($name)
       Deletes the key pair with the specified name (required). Returns true if successful.

TAGS

       These methods allow you to create, delete and fetch resource tags. You may find that you
       rarely need to use these methods directly because every object produced by VM::EC2
       supports a simple tag interface:

         $object = $ec2->describe_volumes(-volume_id=>'vol-12345'); # e.g.
         $tags = $object->tags();
         $name = $tags->{Name};
         $object->add_tags(Role => 'Web Server', Status=>'development);
         $object->delete_tags(Name=>undef);

       See VM::EC2::Generic for a full description of the uniform object tagging interface.

       These methods are most useful when creating and deleting tags for multiple resources
       simultaneously.

   @t = $ec2->describe_tags(-filter=>\%filters);
       Return a series of VM::EC2::Tag objects, each describing an AMI. A single optional -filter
       argument is allowed.

       Available filters are: key, resource-id, resource-type and value. See
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeTags.html

   $bool = $ec2->create_tags(-resource_id=>\@ids,-tag=>{key1=>value1...})
       Tags the resource indicated by -resource_id with the tag(s) in in the hashref indicated by
       -tag. You may specify a single resource by passing a scalar resourceId to -resource_id, or
       multiple resources using an anonymous array. Returns a true value if tagging was
       successful.

       The method name "add_tags()" is an alias for create_tags().

       You may find it more convenient to tag an object retrieved with any of the describe()
       methods using the built-in add_tags() method:

        @snap = $ec2->describe_snapshots(-filter=>{status=>'completed'});
        foreach (@snap) {$_->add_tags(ReadyToUse => 'true')}

       but if there are many snapshots to tag simultaneously, this will be faster:

        @snap = $ec2->describe_snapshots(-filter=>{status=>'completed'});
        $ec2->add_tags(-resource_id=>\@snap,-tag=>{ReadyToUse=>'true'});

       Note that you can tag volumes, snapshots and images owned by other people. Only you will
       be able to see these tags.

   $bool = $ec2->delete_tags(-resource_id=>$id1,-tag=>{key1=>value1...})
       Delete the indicated tags from the indicated resource. Pass an arrayref to operate on
       several resources at once. The tag syntax is a bit tricky. Use a value of undef to delete
       the tag unconditionally:

        -tag => { Role => undef }    # deletes any Role tag

       Any scalar value will cause the tag to be deleted only if its value exactly matches the
       specified value:

        -tag => { Role => 'Server' }  # only delete the Role tag
                                      # if it currently has the value "Server"

       An empty string value ('') will only delete the tag if its value is an empty string, which
       is probably not what you want.

       Pass an array reference of tag names to delete each of the tag names unconditionally (same
       as passing a value of undef):

        $ec2->delete_tags(['Name','Role','Description']);

       You may find it more convenient to delete tags from objects using their delete_tags()
       method:

        @snap = $ec2->describe_snapshots(-filter=>{status=>'completed'});
        foreach (@snap) {$_->delete_tags(Role => undef)}

ELASTIC IP ADDRESSES

       The methods in this section allow you to allocate elastic IP addresses, attach them to
       instances, and delete them. See VM::EC2::ElasticAddress.

   @addr = $ec2->describe_addresses(@public_ips)
   @addr = $ec2->describe_addresses(-public_ip=>\@addr,-allocation_id=>\@id,-filter->\%filters)
       Queries AWS for a list of elastic IP addresses already allocated to you. All arguments are
       optional:

        -public_ip     -- An IP address (in dotted format) or an arrayref of
                          addresses to return information about.
        -allocation_id -- An allocation ID or arrayref of such IDs. Only
                          applicable to VPC addresses.
        -filter        -- A hashref of tag=>value pairs to filter the response
                          on.

       The list of applicable filters can be found at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeAddresses.html.

       This method returns a list of VM::EC2::ElasticAddress.

   $address_info = $ec2->allocate_address([-vpc=>1])
       Request an elastic IP address. Pass -vpc=>1 to allocate a VPC elastic address. The return
       object is a VM::EC2::ElasticAddress.

   $boolean = $ec2->release_address($addr)
       Release an elastic IP address. For non-VPC addresses, you may provide either an IP address
       string, or a VM::EC2::ElasticAddress. For VPC addresses, you must obtain a
       VM::EC2::ElasticAddress first (e.g. with describe_addresses) and then pass that to the
       method.

   $result = $ec2->associate_address($elastic_addr => $instance_id)
       Associate an elastic address with an instance id. Both arguments are mandatory. If you are
       associating a VPC elastic IP address with the instance, the result code will indicate the
       associationId. Otherwise it will be a simple perl truth value ("1") if successful, undef
       if false.

       If this is an ordinary EC2 Elastic IP address, the first argument may either be an
       ordinary string (xx.xx.xx.xx format) or a VM::EC2::ElasticAddress object. However, if it
       is a VPC elastic IP address, then the argument must be a VM::EC2::ElasticAddress as
       returned by describe_addresses(). The reason for this is that the allocationId must be
       retrieved from the object in order to use in the call.

   $bool = $ec2->disassociate_address($elastic_addr)
       Disassociate an elastic address from whatever instance it is currently associated with, if
       any. The result will be true if disassociation was successful.

       If this is an ordinary EC2 Elastic IP address, the argument may either be an ordinary
       string (xx.xx.xx.xx format) or a VM::EC2::ElasticAddress object. However, if it is a VPC
       elastic IP address, then the argument must be a VM::EC2::ElasticAddress as returned by
       describe_addresses(). The reason for this is that the allocationId must be retrieved from
       the object in order to use in the call.

RESERVED INSTANCES

       These methods apply to describing, purchasing and using Reserved Instances.

   @offerings = $ec2->describe_reserved_instances_offerings(@offering_ids)
   @offerings = $ec2->describe_reserved_instances_offerings(%args)
       This method returns a list of the reserved instance offerings currently available for
       purchase. The arguments allow you to filter the offerings according to a variety of
       filters.

       All arguments are optional. If no named arguments are used, then the arguments are treated
       as Reserved Instance Offering IDs.

        -reserved_instances_offering_id  A scalar or arrayref of reserved
                                          instance offering IDs

        -instance_type                   The instance type on which the
                                          reserved instance can be used,
                                          e.g. "c1.medium"

        -availability_zone, -zone        The availability zone in which the
                                          reserved instance can be used.

        -product_description             The reserved instance description.
                                          Valid values are "Linux/UNIX",
                                          "Linux/UNIX (Amazon VPC)",
                                          "Windows", and "Windows (Amazon
                                          VPC)"

        -instance_tenancy                The tenancy of the reserved instance
                                          offering, either "default" or
                                          "dedicated". (VPC instances only)

        -offering_type                  The reserved instance offering type, one of
                                          "Heavy Utilization", "Medium Utilization",
                                          or "Light Utilization".

        -filter                          A set of filters to apply.

       For available filters, see
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeReservedInstancesOfferings.html.

       The returned objects are of type VM::EC2::ReservedInstance::Offering

       This can be combined with the Offering purchase() method as shown here:

        @offerings = $ec2->describe_reserved_instances_offerings(
                 {'availability-zone'   => 'us-east-1a',
                  'instance-type'       => 'c1.medium',
                  'product-description' =>'Linux/UNIX',
                  'duration'            => 31536000,  # this is 1 year
                  });
        $offerings[0]->purchase(5) and print "Five reserved instances purchased\n";

   $id = $ec2->purchase_reserved_instances_offering($offering_id)
   $id = $ec2->purchase_reserved_instances_offering(%args)
       Purchase one or more reserved instances based on an offering.

       Arguments:

        -reserved_instances_offering_id, -id -- The reserved instance offering ID
                                                to purchase (required).

        -instance_count, -count              -- Number of instances to reserve
                                                 under this offer (optional, defaults
                                                 to 1).

       Returns a Reserved Instances Id on success, undef on failure. Also see the purchase()
       method of VM::EC2::ReservedInstance::Offering.

   @res_instances = $ec2->describe_reserved_instances(@res_instance_ids)
   @res_instances = $ec2->describe_reserved_instances(%args)
       This method returns a list of the reserved instances that you currently own.  The
       information returned includes the type of instances that the reservation allows you to
       launch, the availability zone, and the cost per hour to run those reserved instances.

       All arguments are optional. If no named arguments are used, then the arguments are treated
       as Reserved Instance  IDs.

        -reserved_instances_id -- A scalar or arrayref of reserved
                                   instance IDs

        -filter                -- A set of filters to apply.

       For available filters, see
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeReservedInstances.html.

       The returned objects are of type VM::EC2::ReservedInstance

SPOT INSTANCES

       These methods allow you to request spot instances and manipulte spot data feed
       subscriptoins.

   $subscription = $ec2->create_spot_datafeed_subscription($bucket,$prefix)
       This method creates a spot datafeed subscription. Provide the method with the name of an
       S3 bucket associated with your account, and a prefix to be appended to the files written
       by the datafeed. Spot instance usage logs will be written into the requested bucket, and
       prefixed with the desired prefix.

       If no prefix is specified, it defaults to "SPOT_DATAFEED_";

       On success, a VM::EC2::Spot::DatafeedSubscription object is returned;

       Only one datafeed is allowed per account;

   $boolean = $ec2->delete_spot_datafeed_subscription()
       This method delete's the current account's spot datafeed subscription, if any. It takes no
       arguments.

       On success, it returns true.

   $subscription = $ec2->describe_spot_datafeed_subscription()
       This method describes the current account's spot datafeed subscription, if any. It takes
       no arguments.

       On success, a VM::EC2::Spot::DatafeedSubscription object is returned;

   @spot_price_history = $ec2->describe_spot_price_history(@filters)
       This method applies the specified filters to spot instances and returns a list of
       instances, timestamps and their price at the indicated time. Each spot price history point
       is represented as a VM::EC2::Spot::PriceHistory object.

       Option arguments are:

        -start_time      Start date and time of the desired history
                         data, in the form yyyy-mm-ddThh:mm:ss (GMT).
                         The Perl DateTime module provides a convenient
                         way to create times in this format.

        -end_time        End date and time of the desired history
                         data.

        -instance_type   The instance type, e.g. "m1.small", can be
                         a scalar value or an arrayref.

        -product_description  The product description. One of "Linux/UNIX",
                         "SUSE Linux"  or "Windows". Can be a scalar value
                         or an arrayref.

        -availability_zone A single availability zone, such as "us-east-1a".

        -max_results     Maximum number of rows to return in a single
                         call.

        -next_token      Specifies the next set of results to return; used
                         internally.

        -filter          Hashref containing additional filters to apply,

       The following filters are recognized: "instance-type", "product-description", "spot-
       price", "timestamp", "availability-zone". The '*' and '?' wildcards can be used in filter
       values, but numeric comparison operations are not supported by the Amazon API. Note that
       wildcards are not generally allowed in the standard options. Hence if you wish to get spot
       price history in all availability zones in us-east, this will work:

        $ec2->describe_spot_price_history(-filter=>{'availability-zone'=>'us-east*'})

       but this will return an invalid parameter error:

        $ec2->describe_spot_price_history(-availability_zone=>'us-east*')

       If you specify -max_results, then the list of history objects returned may not represent
       the complete result set. In this case, the method more_spot_prices() will return true. You
       can then call describe_spot_price_history() repeatedly with no arguments in order to
       retrieve the remainder of the results. When there are no more results, more_spot_prices()
       will return false.

        my @results = $ec2->describe_spot_price_history(-max_results       => 20,
                                                        -instance_type     => 'm1.small',
                                                        -availability_zone => 'us-east*',
                                                        -product_description=>'Linux/UNIX');
        print_history(\@results);
        while ($ec2->more_spot_prices) {
           @results = $ec2->describe_spot_price_history
           print_history(\@results);
        }

   @requests = $ec2->request_spot_instances(%args)
       This method will request one or more spot instances to be launched when the current spot
       instance run-hour price drops below a preset value and terminated when the spot instance
       run-hour price exceeds the value.

       On success, will return a series of VM::EC2::Spot::InstanceRequest objects, one for each
       instance specified in -instance_count.

       Required arguments:
             -spot_price        The desired spot price, in USD.

             -image_id          ID of an AMI to launch

             -instance_type     Type of the instance(s) to launch, such as "m1.small"

       Optional arguments:
             -instance_count    Maximum number of instances to launch (default 1)

             -type              Spot instance request type; one of "one-time" or "persistent"

             -valid_from        Date/time the request becomes effective, in format
                                  yyyy-mm-ddThh:mm:ss. Default is immediately.

             -valid_until       Date/time the request expires, in format
                                  yyyy-mm-ddThh:mm:ss. Default is to remain in
                                  effect indefinitely.

             -launch_group      Name of the launch group. Instances in the same
                                  launch group are started and terminated together.
                                  Default is to launch instances independently.

             -availability_zone_group  If specified, all instances that are given
                                  the same zone group name will be launched into the
                                  same availability zone. This is independent of
                                  the -availability_zone argument, which specifies
                                  a particular availability zone.

             -key_name          Name of the keypair to use

             -security_group_id Security group ID to use for this instance.
                                Use an arrayref for multiple group IDs

             -security_group    Security group name to use for this instance.
                                Use an arrayref for multiple values.

             -user_data         User data to pass to the instances. Do NOT base64
                                encode this. It will be done for you.

             -availability_zone The availability zone you want to launch the
                                instance into. Call $ec2->regions for a list.
             -zone              Short version of -availability_aone.

             -placement_group   An existing placement group to launch the
                                instance into. Applicable to cluster instances
                                only.
             -placement_tenancy Specify 'dedicated' to launch the instance on a
                                dedicated server. Only applicable for VPC
                                instances.

             -kernel_id         ID of the kernel to use for the instances,
                                overriding the kernel specified in the image.

             -ramdisk_id        ID of the ramdisk to use for the instances,
                                overriding the ramdisk specified in the image.

             -block_devices     Specify block devices to map onto the instances,
                                overriding the values specified in the image.
                                See run_instances() for the syntax of this argument.

             -block_device_mapping  Alias for -block_devices.

             -network_interfaces  Same as the -network_interfaces option in run_instances().

             -monitoring        Pass a true value to enable detailed monitoring.

             -subnet            The ID of the Amazon VPC subnet in which to launch the
                                 spot instance (VPC only).

             -subnet_id         deprecated

             -addressing_type   Deprecated and undocumented, but present in the
                                  current EC2 API documentation.

             -iam_arn           The Amazon resource name (ARN) of the IAM Instance Profile (IIP)
                                  to associate with the instances.

             -iam_name          The name of the IAM instance profile (IIP) to associate with the
                                  instances.

             -ebs_optimized     If true, request an EBS-optimized instance (certain
                                  instance types only).

   @requests = $ec2->cancel_spot_instance_requests(@request_ids)
       This method cancels the pending requests. It does not terminate any instances that are
       already running as a result of the requests. It returns a list of
       VM::EC2::Spot::InstanceRequest objects, whose fields will be unpopulated except for
       spotInstanceRequestId and state.

   @requests = $ec2->describe_spot_instance_requests(@spot_instance_request_ids)
   @requests = $ec2->describe_spot_instance_requests(\%filters)
   @requests =
       $ec2->describe_spot_instance_requests(-spot_instance_request_id=>\@ids,-filter=>\%filters)
       This method will return information about current spot instance requests as a list of
       VM::EC2::Spot::InstanceRequest objects.

       Optional arguments:

        -spot_instance_request_id   -- Scalar or arrayref of request Ids.

        -filter                     -- Tags and other filters to apply.

       There are many filters available, described fully at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/index.html?ApiReference-ItemType-SpotInstanceRequestSetItemType.html:

           availability-zone-group
           create-time
           fault-code
           fault-message
           instance-id
           launch-group
           launch.block-device-mapping.delete-on-termination
           launch.block-device-mapping.device-name
           launch.block-device-mapping.snapshot-id
           launch.block-device-mapping.volume-size
           launch.block-device-mapping.volume-type
           launch.group-id
           launch.image-id
           launch.instance-type
           launch.kernel-id
           launch.key-name
           launch.monitoring-enabled
           launch.ramdisk-id
           launch.network-interface.network-interface-id
           launch.network-interface.device-index
           launch.network-interface.subnet-id
           launch.network-interface.description
           launch.network-interface.private-ip-address
           launch.network-interface.delete-on-termination
           launch.network-interface.group-id
           launch.network-interface.group-name
           launch.network-interface.addresses.primary
           product-description
           spot-instance-request-id
           spot-price
           state
           status-code
           status-message
           tag-key
           tag-value
           tag:<key>
           type
           launched-availability-zone
           valid-from
           valid-until

PLACEMENT GROUPS

       Placement groups Provide low latency and high-bandwidth connectivity between cluster
       instances within a single Availability Zone. Create a placement group and then launch
       cluster instances into it. Instances launched within a placement group participate in a
       full-bisection bandwidth cluster appropriate for HPC applications.

   @groups = $ec2->describe_placement_groups(@group_names)
   @groups = $ec2->describe_placement_groups(\%filters)
   @groups = $ec2->describe_placement_groups(-group_name=>\@ids,-filter=>\%filters)
       This method will return information about cluster placement groups as a list of
       VM::EC2::PlacementGroup objects.

       Optional arguments:

        -group_name         -- Scalar or arrayref of placement group names.

        -filter             -- Tags and other filters to apply.

       The filters available are described fully at:
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribePlacementGroups.html

           group-name
           state
           strategy

   $success = $ec2->create_placement_group($group_name)
   $success = $ec2->create_placement_group(-group_name=>$name,-strategy=>$strategy)
       Creates a placement group that cluster instances are launched into.

       Required arguments:
        -group_name          -- The name of the placement group to create

       Optional:
        -strategy            -- As of 2012-12-23, the only available option is 'cluster'
                                so the parameter defaults to that.

       Returns true on success.

   $success = $ec2->delete_placement_group($group_name)
   $success = $ec2->delete_placement_group(-group_name=>$group_name)
       Deletes a placement group from the account.

       Required arguments:
        -group_name          -- The name of the placement group to delete

       Returns true on success.

VIRTUAL PRIVATE CLOUDS

       EC2 virtual private clouds (VPCs) provide facilities for creating tiered applications
       combining public and private subnetworks, and for extending your home/corporate network
       into the cloud.

   $vpc = $ec2->create_vpc(-cidr_block=>$cidr,-instance_tenancy=>$tenancy)
       Create a new VPC. This can be called with a single argument, in which case it is
       interpreted as the desired CIDR block, or

        $vpc = $ec2->$ec2->create_vpc('10.0.0.0/16') or die $ec2->error_str;

       Or it can be called with named arguments.

       Required arguments:

        -cidr_block      The Classless Internet Domain Routing address, in the
                         form xx.xx.xx.xx/xx. One or more subnets will be allocated
                         from within this block.

       Optional arguments:

        -instance_tenancy "default" or "dedicated". The latter requests AWS to
                         launch all your instances in the VPC on single-tenant
                         hardware (at additional cost).

       See http://docs.amazonwebservices.com/AmazonVPC/latest/UserGuide/VPC_Subnets.html for a
       description of the valid CIDRs that can be used with EC2.

       On success, this method will return a new VM::EC2::VPC object. You can then use this
       object to create new subnets within the VPC:

        $vpc     = $ec2->create_vpc('10.0.0.0/16')    or die $ec2->error_str;
        $subnet1 = $vpc->create_subnet('10.0.0.0/24') or die $vpc->error_str;
        $subnet2 = $vpc->create_subnet('10.0.1.0/24') or die $vpc->error_str;
        $subnet3 = $vpc->create_subnet('10.0.2.0/24') or die $vpc->error_str;

   @vpc = $ec2->describe_vpcs(@vpc_ids)
   @vpc = $ec2->describe_vpcs(\%filter)
   @vpc = $ec2->describe_vpcs(-vpc_id=>\@list,-filter=>\%filter)
       Describe VPCs that you own and return a list of VM::EC2::VPC objects. Call with no
       arguments to return all VPCs, or provide a list of VPC IDs to return information on those
       only. You may also provide a filter list, or named argument forms.

       Optional arguments:

        -vpc_id      A scalar or array ref containing the VPC IDs you want
                     information on.

        -filter      A hashref of filters to apply to the query.

       The filters you can use are described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeVpcs.html

   $success = $ec2->delete_vpc($vpc_id)
   $success = $ec2->delete_vpc(-vpc_id=>$vpc_id)
       Delete the indicated VPC, returning true if successful.

VPC Subnets and Routing

       These methods manage subnet objects and the routing among them. A VPC may have a single
       subnet or many, and routing rules determine whether the subnet has access to the internet
       ("public"), is entirely private, or is connected to a customer gateway device to form a
       Virtual Private Network (VPN) in which your home network's address space is extended into
       the Amazon VPC.

       All instances in a VPC are located in one subnet or another. Subnets may be public or
       private, and are organized in a star topology with a logical router in the middle.

       Although all these methods can be called from VM::EC2 objects, many are more conveniently
       called from the VM::EC2::VPC object family. This allows for steps that typically follow
       each other, such as creating a route table and associating it with a subnet, happen
       automatically. For example, this series of calls creates a VPC with a single subnet,
       creates an Internet gateway attached to the VPC, associates a new route table with the
       subnet and then creates a default route from the subnet to the Internet gateway.

        $vpc       = $ec2->create_vpc('10.0.0.0/16')     or die $ec2->error_str;
        $subnet1   = $vpc->create_subnet('10.0.0.0/24')  or die $vpc->error_str;
        $gateway   = $vpc->create_internet_gateway       or die $vpc->error_str;
        $routeTbl  = $subnet->create_route_table         or die $vpc->error_str;
        $routeTbl->create_route('0.0.0.0/0' => $gateway) or die $vpc->error_str;

   $subnet = $ec2->create_subnet(-vpc_id=>$id,-cidr_block=>$block)
       This method creates a new subnet within the given VPC. Pass a VPC object or VPC ID, and a
       CIDR block string. If successful, the method will return a VM::EC2::VPC::Subnet object.

       Required arguments:

        -vpc_id     A VPC ID or previously-created VM::EC2::VPC object.

        -cidr_block A CIDR block string in the form "xx.xx.xx.xx/xx". The
                    CIDR address must be within the CIDR block previously
                    assigned to the VPC, and must not overlap other subnets
                    in the VPC.

       Optional arguments:

        -availability_zone  The availability zone for the instances launched
                            within this instance, either an availability zone
                            name, or a VM::EC2::AvailabilityZone object. If
                            this is not specified, then AWS chooses a zone for
                            you automatically.

   $success = $ec2->delete_subnet($subnet_id)
   $success = $ec2->delete_subnet(-subnet_id=>$id)
       This method deletes the indicated subnet. It may be called with a single argument
       consisting of the subnet ID, or a named argument form with the argument -subnet_id.

   @subnets = $ec2->describe_subnets(@subnet_ids)
   @subnets = $ec2->describe_subnets(\%filters)
   @subnets = $ec2->describe_subnets(-subnet_id=>$id, -filter   => \%filters)
       This method returns a list of VM::EC2::VPC::Subnet objects. Called with no arguments, it
       returns all Subnets (not filtered by VPC Id). Pass a list of subnet IDs or a filter
       hashref in order to restrict the search.

       Optional arguments:

        -subnet_id     Scalar or arrayref of subnet IDs.
        -filter        Hashref of filters.

       Available filters are described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeSubnets.html

   $table = $ec2->create_route_table($vpc_id)
   $table = $ec2->create_route_table(-vpc_id=>$id)
       This method creates a new route table within the given VPC and returns a
       VM::EC2::VPC::RouteTable object. By default, every route table includes a local route that
       enables traffic to flow within the VPC. You may add additional routes using
       create_route().

       This method can be called using a single argument corresponding to VPC ID for the new
       route table, or with the named argument form.

       Required arguments:

        -vpc_id     A VPC ID or previously-created VM::EC2::VPC object.

   $success = $ec2->delete_route_table($route_table_id)
   $success = $ec2->delete_route_table(-route_table_id=>$id)
       This method deletes the indicated route table and all the route entries within it. It may
       not be called on the main route table, or if the route table is currently associated with
       a subnet.

       The method can be called with a single argument corresponding to the route table's ID, or
       using the named form with argument -route_table_id.

   @tables = $ec2->describe_route_tables(@route_table_ids)
   @tables = $ec2->describe_route_tables(\%filters)
   @tables = $ec2->describe_route_tables(-route_table_id=> \@ids, -filter        => \%filters);
       This method describes all or some of the route tables available to you. You may use the
       filter to restrict the search to a particular type of route table using one of the filters
       described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeRouteTables.html.

       Some of the commonly used filters are:

        vpc-id                  ID of the VPC the route table is in.
        association.subnet-id   ID of the subnet the route table is
                                 associated with.
        route.state             State of the route, either 'active' or 'blackhole'
        tag:<key>               Value of a tag

   $associationId = $ec2->associate_route_table($subnet_id => $route_table_id)
   $associationId = $ec2->associate_route_table(-subnet_id      => $id, -route_table_id => $id)
       This method associates a route table with a subnet. Both objects must be in the same VPC.
       You may use either string IDs, or VM::EC2::VPC::RouteTable and VM::EC2::VPC::Subnet
       objects.

       On success, an associationID is returned, which you may use to disassociate the route
       table from the subnet later. The association ID can also be found by searching through the
       VM::EC2::VPC::RouteTable object.

       Required arguments:

        -subnet_id      The subnet ID or a VM::EC2::VPC::Subnet object.

        -route_table_id The route table ID or a M::EC2::VPC::RouteTable object.

       It may be more convenient to call the VM::EC2::VPC::Subnet->associate_route_table() or
       VM::EC2::VPC::RouteTable->associate_subnet() methods, which are front ends to this method.

   $success = $ec2->dissociate_route_table($association_id)
   $success = $ec2->dissociate_route_table(-association_id => $id)
       This method disassociates a route table from a subnet. You must provide the association ID
       (either returned from associate_route_table() or found among the associations() of a
       RouteTable object). You may use the short single-argument form, or the longer named
       argument form with the required argument -association_id.

       The method returns true on success.

   $new_association = $ec2->replace_route_table_association($association_id=>$route_table_id)
   $new_association = $ec2->replace_route_table_association(-association_id => $id,
       -route_table_id => $id)
       This method changes the route table associated with a given subnet. You must pass the
       replacement route table ID and the association ID. To replace the main route table, use
       its association ID and the ID of the route table you wish to replace it with.

       On success, a new associationID is returned.

       Required arguments:

        -association_id  The association ID

        -route_table_id   The route table ID or a M::EC2::VPC::RouteTable object.

   $success = $ec2->create_route($route_table_id,$destination,$target)
   $success = $ec2->create_route(-route_table_id => $id, -destination_cidr_block => $block,
       -target=>$target)
       This method creates a routing rule in a route table within a VPC. It takes three mandatory
       arguments consisting of the route table, the CIDR address block to match packet
       destinations against, and a target to route matching packets to. The target may be an
       internet gateway, a NAT instance, or a network interface ID.

       Network packets are routed by matching their destination addresses against a CIDR block.
       For example, 0.0.0.0/0 matches all addresses, while 10.0.1.0/24 matches 10.0.1.*
       addresses. When a packet matches more than one rule, the most specific matching routing
       rule is chosen.

       In the named argument form, the following arguments are recognized:

        -route_table_id    The ID of a route table, or a VM::EC2::VPC::RouteTable
                           object.

        -destination_cidr_block
                           The CIDR address block to match against packet destinations.

        -destination       A shorthand version of -destination_cidr_block.

        -target            The destination of matching packets. See below for valid
                           targets.

       The -target value can be any one of the following:

        1. A VM::EC2::VPC::InternetGateway object, or an internet gateway ID matching
           the regex /^igw-[0-9a-f]{8}$/

        2. A VM::EC2::Instance object, or an instance ID matching the regex
        /^i-[0-9a-f]{8}$/.

        3. A VM::EC2::NetworkInterface object, or a network interface ID
           matching the regex /^eni-[0-9a-f]{8}$/.

       On success, this method returns true.

   $success = $ec2->delete_route($route_table_id,$destination_block)
       This method deletes a route in the specified routing table. The destination CIDR block is
       used to indicate which route to delete. On success, the method returns true.

   $success = $ec2->replace_route($route_table_id,$destination,$target)
   $success = $ec2->replace_route(-route_table_id => $id, -destination_cidr_block => $block,
       -target=>$target)
       This method replaces an existing routing rule in a route table within a VPC. It takes
       three mandatory arguments consisting of the route table, the CIDR address block to match
       packet destinations against, and a target to route matching packets to. The target may be
       an internet gateway, a NAT instance, or a network interface ID.

       Network packets are routed by matching their destination addresses against a CIDR block.
       For example, 0.0.0.0/0 matches all addresses, while 10.0.1.0/24 matches 10.0.1.*
       addresses. When a packet matches more than one rule, the most specific matching routing
       rule is chosen.

       In the named argument form, the following arguments are recognized:

        -route_table_id    The ID of a route table, or a VM::EC2::VPC::RouteTable
                           object.

        -destination_cidr_block
                           The CIDR address block to match against packet destinations.

        -destination       A shorthand version of -destination_cidr_block.

        -target            The destination of matching packets. See below for valid
                           targets.

       The -target value can be any one of the following:

        1. A VM::EC2::VPC::InternetGateway object, or an internet gateway ID matching
           the regex /^igw-[0-9a-f]{8}$/

        2. A VM::EC2::Instance object, or an instance ID matching the regex
        /^i-[0-9a-f]{8}$/.

        3. A VM::EC2::NetworkInterface object, or a network interface ID
           matching the regex /^eni-[0-9a-f]{8}$/.

       On success, this method returns true.

   $gateway = $ec2->create_internet_gateway()
       This method creates a new Internet gateway. It takes no arguments and returns a
       VM::EC2::VPC::InternetGateway object. Gateways are initially independent of any VPC, but
       later can be attached to one or more VPCs using attach_internet_gateway().

   $success = $ec2->delete_internet_gateway($internet_gateway_id)
   $success = $ec2->delete_internet_gateway(-internet_gateway_id=>$id)
       This method deletes the indicated internet gateway. It may be called with a single
       argument corresponding to the route table's ID, or using the named form with argument
       -internet_gateway_id.

   @gateways = $ec2->describe_internet_gateways(@gateway_ids)
   @gateways = $ec2->describe_internet_gateways(\%filters)
   @gateways = $ec2->describe_internet_gateways(-internet_gateway_id=>\@ids, -filter
       =>\$filters)
       This method describes all or some of the internet gateways available to you. You may use
       the filter to restrict the search to a particular type of internet gateway using one or
       more of the filters described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeInternetGateways.html.

       Some of the commonly used filters are:

        attachment.vpc-id       ID of one of the VPCs the gateway is attached to
        attachment.state        State of the gateway, always "available"
        tag:<key>               Value of a tag

       On success this method returns a list of VM::EC2::VPC::InternetGateway objects.

   $boolean = $ec2->attach_internet_gateway($internet_gateway_id,$vpc_id)
   $boolean = $ec2->attach_internet_gateway(-internet_gateway_id => $id, -vpc_id              =>
       $id)
       This method attaches an internet gateway to a VPC.  You can use internet gateway and VPC
       IDs, or their corresponding VM::EC2::VPC::InternetGateway and VM::EC2::VPC objects.

       Required arguments:

        -internet_gateway_id ID of the network interface to attach.
        -vpc_id              ID of the instance to attach the interface to.

       On success, this method a true value.

       Note that it may be more convenient to attach and detach gateways via methods in the
       VM::EC2::VPC and VM::EC2::VPC::Gateway objects.

        $vpc->attach_internet_gateway($gateway);
        $gateway->attach($vpc);

   $boolean = $ec2->detach_internet_gateway($internet_gateway_id,$vpc_id)
   $boolean = $ec2->detach_internet_gateway(-internet_gateway_id => $id, -vpc_id              =>
       $id)
       This method detaches an internet gateway to a VPC.  You can use internet gateway and VPC
       IDs, or their corresponding VM::EC2::VPC::InternetGateway and VM::EC2::VPC objects.

       Required arguments:

        -internet_gateway_id ID of the network interface to detach.
        -vpc_id              ID of the VPC to detach the gateway from.

       On success, this method a true value.

       Note that it may be more convenient to detach and detach gateways via methods in the
       VM::EC2::VPC and VM::EC2::VPC::Gateway objects.

        $vpc->detach_internet_gateway($gateway);
        $gateway->detach($vpc);

   @acls = $ec2->describe_network_acls(-network_acl_id=>\@ids, -filter=>\%filters)
   @acls = $ec2->describe_network_acls(\@network_acl_ids)
   @acls = $ec2->describe_network_acls(%filters)
       Provides information about network ACLs.

       Returns a series of VM::EC2::VPC::NetworkAcl objects.

       Optional parameters are:

        -network_acl_id      -- ID of the network ACL(s) to return information on.
                                This can be a string scalar, or an arrayref.

        -filter              -- Tags and other filters to apply.

       The filter argument is a hashreference in which the keys are the filter names, and the
       values are the match strings. Some filters accept wildcards.

       There are a number of filters, which are listed in full at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeNetworkAcls.html

       Here is a alpha-sorted list of filter names: association.association-id,
       association.network-acl-id, association.subnet-id, default, entry.cidr, entry.egress,
       entry.icmp.code, entry.icmp.type, entry.port-range.from, entry.port-range.to,
       entry.protocol, entry.rule-action, entry.rule-number, network-acl-id, tag-key, tag-value,
       tag:key, vpc-id

   $acl = $ec2->create_network_acl(-vpc_id=>$vpc_id)
   $acl = $ec2->create_network_acl($vpc_id)
       Creates a new network ACL in a VPC. Network ACLs provide an optional layer of security (on
       top of security groups) for the instances in a VPC.

       Arguments:

        -vpc_id            -- The VPC ID to create the ACL in

       Retuns a VM::EC2::VPC::NetworkAcl object on success.

   $boolean = $ec2->delete_network_acl(-network_acl_id=>$id)
   $boolean = $ec2->delete_network_acl($id)
       Deletes a network ACL from a VPC. The ACL must not have any subnets associated with it.
       The default network ACL cannot be deleted.

       Arguments:

        -network_acl_id    -- The ID of the network ACL to delete

       Returns true on successful deletion.

   $boolean = $ec2->create_network_acl_entry(%args)
       Creates an entry (i.e., rule) in a network ACL with the rule number you specified. Each
       network ACL has a set of numbered ingress rules and a separate set of numbered egress
       rules. When determining whether a packet should be allowed in or out of a subnet
       associated with the ACL, Amazon VPC processes the entries in the ACL according to the rule
       numbers, in ascending order.

       Arguments:

        -network_acl_id       -- ID of the ACL where the entry will be created
                                 (Required)
        -rule_number          -- Rule number to assign to the entry (e.g., 100).
                                 ACL entries are processed in ascending order by
                                 rule number.  Positive integer from 1 to 32766.
                                 (Required)
        -protocol             -- The IP protocol the rule applies to. You can use
                                 -1 to mean all protocols.  See
                                 http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml
                                 for a list of protocol numbers. (Required)
        -rule_action          -- Indicates whether to allow or deny traffic that
                                  matches the rule.  allow | deny (Required)
        -egress               -- Indicates whether this rule applies to egress
                                 traffic from the subnet (true) or ingress traffic
                                 to the subnet (false).  Default is false.
        -cidr_block           -- The CIDR range to allow or deny, in CIDR notation
                                 (e.g., 172.16.0.0/24). (Required)
        -icmp_code            -- For the ICMP protocol, the ICMP code. You can use
                                 -1 to specify all ICMP codes for the given ICMP
                                 type.  Required if specifying 1 (ICMP) for protocol.
        -icmp_type            -- For the ICMP protocol, the ICMP type. You can use
                                 -1 to specify all ICMP types.  Required if
                                 specifying 1 (ICMP) for the protocol
        -port_from            -- The first port in the range.  Required if specifying
                                 6 (TCP) or 17 (UDP) for the protocol.
        -port_to              -- The last port in the range.  Required if specifying
                                 6 (TCP) or 17 (UDP) for the protocol.

       Returns true on successful creation.

   $success = $ec2->delete_network_acl_entry(-network_acl_id=>$id, -rule_number   =>$int, -egress
       =>$bool)
       Deletes an ingress or egress entry (i.e., rule) from a network ACL.

       Arguments:

        -network_acl_id       -- ID of the ACL where the entry will be created

        -rule_number          -- Rule number of the entry (e.g., 100).

       Optional arguments:

        -egress    -- Whether the rule to delete is an egress rule (true) or ingress
                      rule (false).  Default is false.

       Returns true on successful deletion.

   $assoc_id = $ec2->replace_network_acl_association(-association_id=>$assoc_id,
       -network_acl_id=>$id)
       Changes which network ACL a subnet is associated with. By default when you create a
       subnet, it's automatically associated with the default network ACL.

       Arguments:

        -association_id    -- The ID of the association to replace

        -network_acl_id    -- The ID of the network ACL to associated the subnet with

       Returns the new association ID.

   $success = $ec2->replace_network_acl_entry(%args)
       Replaces an entry (i.e., rule) in a network ACL.

       Arguments:

        -network_acl_id       -- ID of the ACL where the entry will be created
                                 (Required)
        -rule_number          -- Rule number of the entry to replace. (Required)
        -protocol             -- The IP protocol the rule applies to. You can use
                                 -1 to mean all protocols.  See
                                 http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml
                                 for a list of protocol numbers. (Required)
        -rule_action          -- Indicates whether to allow or deny traffic that
                                  matches the rule.  allow | deny (Required)
        -egress               -- Indicates whether this rule applies to egress
                                 traffic from the subnet (true) or ingress traffic
                                 to the subnet (false).  Default is false.
        -cidr_block           -- The CIDR range to allow or deny, in CIDR notation
                                 (e.g., 172.16.0.0/24). (Required)
        -icmp_code            -- For the ICMP protocol, the ICMP code. You can use
                                 -1 to specify all ICMP codes for the given ICMP
                                 type.  Required if specifying 1 (ICMP) for protocol.
        -icmp_type            -- For the ICMP protocol, the ICMP type. You can use
                                 -1 to specify all ICMP types.  Required if
                                 specifying 1 (ICMP) for the protocol
        -port_from            -- The first port in the range.  Required if specifying
                                 6 (TCP) or 17 (UDP) for the protocol.
        -port_to              -- The last port in the range.  Only required if
                                 specifying 6 (TCP) or 17 (UDP) for the protocol and
                                 is a different port than -port_from.

       Returns true on successful replacement.

DHCP Options

       These methods manage DHCP Option objects, which can then be applied to a VPC to configure
       the DHCP options applied to running instances.

   $options = $ec2->create_dhcp_options(\%configuration_list)
       This method creates a DhcpOption object, The single required argument is a configuration
       list hash (which can be passed either as a hashref or a flattened hash) with one or more
       of the following keys:

        -domain_name            Domain name for instances running in this VPC.

        -domain_name_servers    Scalar or arrayref containing up to 4 IP addresses of
                                domain name servers for this VPC.

        -ntp_servers            Scalar or arrayref containing up to 4 IP addresses
                                of network time protocol servers

        -netbios_name_servers   Scalar or arrayref containing up to 4 IP addresses for
                                NetBIOS name servers.

        -netbios_node_type      The NetBios node type (1,2,4 or 8). Amazon recommends
                                using "2" at this time.

       On successful completion, a VM::EC2::VPC::DhcpOptions object will be returned. This can be
       associated with a VPC using the VPC object's set_dhcp_options() method:

        $vpc     = $ec2->create_vpc(...);
        $options = $ec2->create_dhcp_options(-domain_name=>'test.com',
                                             -domain_name_servers=>['204.16.255.55','216.239.34.10']);
        $vpc->set_dhcp_options($options);

   $success = $ec2->delete_dhcp_options($dhcp_id)
       Delete the indicated DHCPOptions, returning true if successful. You may also use the named
       argument -dhcp_options_id..

   @options = $ec2->describe_dhcp_options(@option_ids)
   @options = $ec2->describe_dhcp_options(\%filters)
   @options = $ec2->describe_dhcp_options(-dhcp_options_id=>$id, -filter         => \%filters)
       This method returns a list of VM::EC2::VPC::DhcpOptions objects, which describe a set of
       DHCP options that can be assigned to a VPC. Called with no arguments, it returns all
       DhcpOptions. Pass a list of option IDs or a filter hashref in order to restrict the
       search.

       Optional arguments:

        -dhcp_options_id     Scalar or arrayref of DhcpOption IDs.
        -filter              Hashref of filters.

       Available filters are described at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeDhcpOptions.html.

   $success = $ec2->associate_dhcp_options($vpc_id => $dhcp_id)
   $success = $ec2->associate_dhcp_options(-vpc_id => $vpc_id,-dhcp_options_id => $dhcp_id)
       Associate a VPC ID with a DHCP option set. Pass an ID of 'default' to restore the default
       DHCP options for the VPC.

Virtual Private Networks

       These methods create and manage Virtual Private Network (VPN) connections to an Amazon
       Virtual Private Cloud (VPC).

   @gtwys = $ec2->describe_vpn_gateways(-vpn_gateway_id=>\@ids, -filter        =>\%filters)
   @gtwys = $ec2->describe_vpn_gateways(@vpn_gateway_ids)
   @gtwys = $ec2->describe_vpn_gateways(%filters)
       Provides information on VPN gateways.

       Return a series of VM::EC2::VPC::VpnGateway objects.  When called with no arguments,
       returns all VPN gateways.  Pass a list of VPN gateway IDs or use the assorted filters to
       restrict the search.

       Optional parameters are:

        -vpn_gateway_id         ID of the gateway(s) to return information on.
                                This can be a string scalar, or an arrayref.

        -filter                 Tags and other filters to apply.

       The filter argument is a hashreference in which the keys are the filter names, and the
       values are the match strings. Some filters accept wildcards.

       There are a number of filters, which are listed in full at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeVpnGateways.html

       Here is a alpha-sorted list of filter names: attachment.state, attachment.vpc-id,
       availability-zone, state, tag-key, tag-value, tag:key, type, vpn-gateway-id

   $vpn_gateway = $ec2->create_vpn_gateway(-type=>$type)
   $vpn_gateway = $ec2->create_vpn_gateway($type)
   $vpn_gateway = $ec2->create_vpn_gateway
       Creates a new virtual private gateway. A virtual private gateway is the VPC-side endpoint
       for a VPN connection. You can create a virtual private gateway before creating the VPC
       itself.

        -type switch is optional as there is only one type as of API 2012-06-15

       Returns a VM::EC2::VPC::VpnGateway object on success

   $success = $ec2->delete_vpn_gateway(-vpn_gateway_id=>$id);
   $success = $ec2->delete_vpn_gateway($id);
       Deletes a virtual private gateway.  Use this when a VPC and all its associated components
       are no longer needed.  It is recommended that before deleting a virtual private gateway,
       detach it from the VPC and delete the VPN connection.  Note that it is not necessary to
       delete the virtual private gateway if the VPN connection between the VPC and data center
       needs to be recreated.

       Arguments:

        -vpn_gateway_id    -- The ID of the VPN gateway to delete.

       Returns true on successful deletion

   $state = $ec2->attach_vpn_gateway(-vpn_gateway_id=>$vpn_gtwy_id, -vpc_id        =>$vpc_id)
       Attaches a virtual private gateway to a VPC.

       Arguments:

        -vpc_id          -- The ID of the VPC to attach the VPN gateway to

        -vpn_gateway_id  -- The ID of the VPN gateway to attach

       Returns the state of the attachment, one of:
          attaching | attached | detaching | detached

   $success = $ec2->detach_vpn_gateway(-vpn_gateway_id=>$vpn_gtwy_id, -vpc_id        =>$vpc_id)
       Detaches a virtual private gateway from a VPC. You do this if you're planning to turn off
       the VPC and not use it anymore. You can confirm a virtual private gateway has been
       completely detached from a VPC by describing the virtual private gateway (any attachments
       to the virtual private gateway are also described).

       You must wait for the attachment's state to switch to detached before you can delete the
       VPC or attach a different VPC to the virtual private gateway.

       Arguments:

        -vpc_id          -- The ID of the VPC to detach the VPN gateway from

        -vpn_gateway_id  -- The ID of the VPN gateway to detach

       Returns true on successful detachment.

   @vpn_connections = $ec2->describe_vpn_connections(-vpn_connection_id=>\@ids,
       -filter=>\%filters);
   @vpn_connections = $ec2->describe_vpn_connections(@vpn_connection_ids)
   @vpn_connections = $ec2->describe_vpn_connections(%filters);
       Gives information about VPN connections

       Returns a series of VM::EC2::VPC::VpnConnection objects.

       Optional parameters are:

        -vpn_connection_id      ID of the connection(s) to return information on.
                                This can be a string scalar, or an arrayref.

        -filter                 Tags and other filters to apply.

       The filter argument is a hashreference in which the keys are the filter names, and the
       values are the match strings. Some filters accept wildcards.

       There are a number of filters, which are listed in full at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeVpnConnections.html

       Here is a alpha-sorted list of filter names: customer-gateway-configuration, customer-
       gateway-id, state, tag-key, tag-value, tag:key, type, vpn-connection-id, vpn-gateway-id

   $vpn_connection = $ec2->create_vpn_connection(-type               =>$type,
       -customer_gateway_id=>$gtwy_id, -vpn_gateway_id     =>$vpn_id)
       Creates a new VPN connection between an existing virtual private gateway and a VPN
       customer gateway. The only supported connection type is ipsec.1.

       Required Arguments:

        -customer_gateway_id       -- The ID of the customer gateway

        -vpn_gateway_id            -- The ID of the VPN gateway

       Optional arguments:
        -type                      -- Default is the only currently available option:
                                      ipsec.1 (API 2012-06-15)

        -static_routes_only        -- Indicates whether or not the VPN connection
                                      requires static routes. If you are creating a VPN
                                      connection for a device that does not support
                                      BGP, you must specify this value as true.

       Returns a VM::EC2::VPC::VpnConnection object.

   $success = $ec2->delete_vpn_connection(-vpn_connection_id=>$vpn_id)
   $success = $ec2->delete_vpn_connection($vpn_id)
       Deletes a VPN connection. Use this if you want to delete a VPC and all its associated
       components. Another reason to use this operation is if you believe the tunnel credentials
       for your VPN connection have been compromised. In that situation, you can delete the VPN
       connection and create a new one that has new keys, without needing to delete the VPC or
       virtual private gateway. If you create a new VPN connection, you must reconfigure the
       customer gateway using the new configuration information returned with the new VPN
       connection ID.

       Arguments:

        -vpn_connection_id       -- The ID of the VPN connection to delete

       Returns true on successful deletion.

   @gtwys = $ec2->describe_customer_gateways(-customer_gateway_id=>\@ids, -filter
       =>\%filters)
   @gtwys = $ec2->describe_customer_gateways(\@customer_gateway_ids)
   @gtwys = $ec2->describe_customer_gateways(%filters)
       Provides information on VPN customer gateways.

       Returns a series of VM::EC2::VPC::CustomerGateway objects.

       Optional parameters are:

        -customer_gateway_id    ID of the gateway(s) to return information on.
                                This can be a string scalar, or an arrayref.

        -filter                 Tags and other filters to apply.

       The filter argument is a hashreference in which the keys are the filter names, and the
       values are the match strings. Some filters accept wildcards.

       There are a number of filters, which are listed in full at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeCustomerGateways.html

       Here is a alpha-sorted list of filter names: bgp-asn, customer-gateway-id, ip-address,
       state, type, tag-key, tag-value, tag:key

   $cust_gtwy = $ec2->create_customer_gateway(-type      =>$type, -ip_address=>$ip, -bgp_asn
       =>$asn)
       Provides information to AWS about a VPN customer gateway device. The customer gateway is
       the appliance at the customer end of the VPN connection (compared to the virtual private
       gateway, which is the device at the AWS side of the VPN connection).

       Arguments:

        -ip_address     -- The IP address of the customer gateway appliance

        -bgp_asn        -- The Border Gateway Protocol (BGP) Autonomous System Number
                           (ASN) of the customer gateway

        -type           -- Optional as there is only currently (2012-06-15 API) only
                           one type (ipsec.1)

        -ip             -- Alias for -ip_address

       Returns a VM::EC2::VPC::CustomerGateway object on success.

   $success = $ec2->delete_customer_gateway(-customer_gateway_id=>$id)
   $success = $ec2->delete_customer_gateway($id)
       Deletes a VPN customer gateway. You must delete the VPN connection before deleting the
       customer gateway.

       Arguments:

        -customer_gateway_id     -- The ID of the customer gateway to delete

       Returns true on successful deletion.

   $success = $ec2->create_vpn_connection_route(-destination_cidr_block=>$cidr,
       -vpn_connection_id     =>$id)
       Creates a new static route associated with a VPN connection between an existing virtual
       private gateway and a VPN customer gateway. The static route allows traffic to be routed
       from the virtual private gateway to the VPN customer gateway.

       Arguments:

        -destination_cidr_block     -- The CIDR block associated with the local subnet
                                        of the customer data center.

        -vpn_connection_id           -- The ID of the VPN connection.

       Returns true on successsful creation.

   $success = $ec2->delete_vpn_connection_route(-destination_cidr_block=>$cidr,
       -vpn_connection_id     =>$id)
       Deletes a static route associated with a VPN connection between an existing virtual
       private gateway and a VPN customer gateway. The static route allows traffic to be routed
       from the virtual private gateway to the VPN customer gateway.

       Arguments:

        -destination_cidr_block     -- The CIDR block associated with the local subnet
                                        of the customer data center.

        -vpn_connection_id           -- The ID of the VPN connection.

       Returns true on successsful deletion.

   $success = $ec2->disable_vgw_route_propogation(-route_table_id=>$rt_id, -gateway_id
       =>$gtwy_id)
       Disables a virtual private gateway (VGW) from propagating routes to the routing tables of
       an Amazon VPC.

       Arguments:

        -route_table_id        -- The ID of the routing table.

        -gateway_id            -- The ID of the virtual private gateway.

       Returns true on successful disablement.

   $success = $ec2->enable_vgw_route_propogation(-route_table_id=>$rt_id, -gateway_id
       =>$gtwy_id)
       Enables a virtual private gateway (VGW) to propagate routes to the routing tables of an
       Amazon VPC.

       Arguments:

        -route_table_id        -- The ID of the routing table.

        -gateway_id            -- The ID of the virtual private gateway.

       Returns true on successful enablement.

Elastic Network Interfaces

       These methods create and manage Elastic Network Interfaces (ENI). Once created, an ENI can
       be attached to instances and/or be associated with a public IP address. ENIs can only be
       used in conjunction with VPC instances.

   $interface = $ec2->create_network_interface($subnet_id)
   $interface = $ec2->create_network_interface(%args)
       This method creates an elastic network interface (ENI). If only a single argument is
       provided, it is treated as the ID of the VPC subnet to associate with the ENI. If multiple
       arguments are provided, they are treated as -arg=>value parameter pairs.

       Arguments:

       The -subnet_id argument is mandatory. Others are optional.

        -subnet_id           --  ID of the VPC subnet to associate with the network
                                  interface (mandatory)

        -private_ip_address  --  The primary private IP address of the network interface,
                                  or a reference to an array of private IP addresses. In the
                                  latter case, the first element of the array becomes the
                                  primary address, and the subsequent ones become secondary
                                  addresses. If no private IP address is specified, one will
                                  be chosen for you. See below for more information on this
                                  parameter.

        -private_ip_addresses -- Same as -private_ip_address, for readability.

        -secondary_ip_address_count -- An integer requesting this number of secondary IP
                                 addresses to be allocated automatically. If present,
                                 cannot provide any secondary addresses explicitly.

        -description          -- Description of this ENI.

        -security_group_id    -- Array reference or scalar containing IDs of the security
                                  group(s) to assign to this interface.

       You can assign multiple IP addresses to the interface explicitly, or by allowing EC2 to
       choose addresses within the designated subnet automatically. The following examples
       demonstrate the syntax:

        # one primary address, chosen explicitly
        -private_ip_address => '192.168.0.12'

        # one primary address and two secondary addresses, chosen explicitly
        -private_ip_address => ['192.168.0.12','192.168.0.200','192.168.0.201']

        # one primary address chosen explicitly, and two secondaries chosen automatically
        -private_ip_address => ['192.168.0.12','auto','auto']

        # one primary address chosen explicitly, and two secondaries chosen automatically (another syntax)
        -private_ip_address => ['192.168.0.12',2]

        # one primary address chosen automatically, and two secondaries chosen automatically
        -private_ip_address => [auto,2]

       You cannot assign some secondary addresses explicitly and others automatically on the same
       ENI. If you provide no -private_ip_address parameter at all, then a single private IP
       address will be chosen for you (the same as -private_ip_address=>'auto').

       The return value is a VM::EC2::NetworkInterface object

   $result = $ec2->assign_private_ip_addresses(%args)
       Assign one or more secondary private IP addresses to a network interface. You can either
       set the addresses explicitly, or provide a count of secondary addresses, and let Amazon
       select them for you.

       Required arguments:

        -network_interface_id    The network interface to which the IP address(es)
                                 will be assigned.

        -private_ip_address      One or more secondary IP addresses, as a scalar string
        -private_ip_addresses    or array reference. (The two arguments are equivalent).

       Optional arguments:

        -allow_reassignment      If true, allow assignment of an IP address is already in
                                 use by another network interface or instance.

       The following are valid arguments to -private_ip_address:

        -private_ip_address => '192.168.0.12'                    # single address
        -private_ip_address => ['192.168.0.12','192.168.0.13]    # multiple addresses
        -private_ip_address => 3                                 # autoselect three addresses

       The mixed form of address, such as ['192.168.0.12','auto'] is not allowed in this call.

       On success, this method returns true.

   $result = $ec2->unassign_private_ip_addresses(%args)
       Unassign one or more secondary private IP addresses from a network interface.

       Required arguments:

        -network_interface_id    The network interface to which the IP address(es)
                                 will be assigned.

        -private_ip_address      One or more secondary IP addresses, as a scalar string
        -private_ip_addresses    or array reference. (The two arguments are equivalent).

       The following are valid arguments to -private_ip_address:

        -private_ip_address => '192.168.0.12'                    # single address
        -private_ip_address => ['192.168.0.12','192.168.0.13]    # multiple addresses

       On success, this method returns true.

   $result = $ec2->delete_network_interface($network_interface_id);
   $result = $ec2->delete_network_interface(-network_interface_id => $id);
       Deletes the specified network interface. Returns a boolean indicating success of the
       delete operation.

   @ifs = $ec2->describe_network_interfaces(@interface_ids)
   @ifs = $ec2->describe_network_interfaces(\%filters)
   @ifs =
       $ec2->describe_network_interfaces(-network_interface_id=>\@interface_ids,-filter=>\%filters)
       Return a list of elastic network interfaces as VM::EC2::VPC::NetworkInterface objects. You
       may restrict the list by passing a list of network interface IDs, a hashref of filters or
       by using the full named-parameter form.

       Optional arguments:

        -network_interface_id    A single network interface ID or an arrayref to
                                  a list of IDs.

        -filter                  A hashref for filtering on tags and other attributes.

       The list of valid filters can be found at
       http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeNetworkInterfaces.html.

   @data = $ec2->describe_network_interface_attribute($network_id,$attribute)
       This method returns network interface attributes. Only one attribute can be retrieved at a
       time. The following is the list of attributes that can be retrieved:

        description           -- hashref
        groupSet              -- hashref
        sourceDestCheck       -- hashref
        attachment            -- hashref

       These values can be retrieved more conveniently from the VM::EC2::NetworkInterface object,
       so there is no attempt to parse the results of this call into Perl objects.

   $boolean = $ec2->modify_network_interface_attribute($interface_id,-$attribute_name=>$value)
       This method changes network interface attributes. Only one attribute can be set per call
       The following is the list of attributes that can be set:

        -description             -- interface description
        -security_group_id       -- single security group ID or arrayref to a list of group ids
        -source_dest_check       -- boolean; if false enables packets to be forwarded, and is necessary
                                      for NAT and other router tasks
        -delete_on_termination   -- [$attachment_id=>$delete_on_termination]; Pass this a two-element
                                      array reference consisting of the attachment ID and a boolean
                                      indicating whether deleteOnTermination should be enabled for
                                      this attachment.

   $boolean = $ec2->reset_network_interface_attribute($interface_id => $attribute_name)
       This method resets the named network interface attribute to its default value. Only one
       attribute can be reset per call. The AWS documentation is not completely clear on this
       point, but it appears that the only attribute that can be reset using this method is:

        source_dest_check       -- Turns on source destination checking

       For consistency with modify_network_interface_attribute, you may specify attribute names
       with or without a leading dash, and using either under_score or mixedCase naming:

        $ec2->reset_network_interface_atribute('eni-12345678' => 'source_dest_check');
        $ec2->reset_network_interface_atribute('eni-12345678' => '-source_dest_check');
        $ec2->reset_network_interface_atribute('eni-12345678' => sourceDestCheck);

   $attachmentId =
       $ec2->attach_network_interface($network_interface_id,$instance_id,$device_index)
   $attachmentId = $ec2->attach_network_interface(-network_interface_id => $id, -instance_id
       => $id, -device_index         => $index)
       This method attaches a network interface to an instance using the indicated device index.
       You can use instance and network interface IDs, or VM::EC2::Instance and
       VM::EC2::NetworkInterface objects. You may use an integer for -device_index, or use the
       strings "eth0", "eth1" etc.

       Required arguments:

        -network_interface_id ID of the network interface to attach.
        -instance_id          ID of the instance to attach the interface to.
        -device_index         Network device number to use (e.g. 0 for eth0).

       On success, this method returns the attachmentId of the new attachment (not a
       VM::EC2::NetworkInterface::Attachment object, due to an AWS API inconsistency).

       Note that it may be more convenient to attach and detach network interfaces via methods in
       the VM::EC2::Instance and VM::EC2::NetworkInterface objects:

        $instance->attach_network_interface($interface=>'eth0');
        $interface->attach($instance=>'eth0');

   $boolean = $ec2->detach_network_interface($attachment_id [,$force])
       This method detaches a network interface from an instance. Both the network interface and
       instance are specified using their attachmentId. If the $force flag is present, and true,
       then the detachment will be forced even if the interface is in use.

       Note that it may be more convenient to attach and detach network interfaces via methods in
       the VM::EC2::Instance and VM::EC2::NetworkInterface objects:

        $instance->detach_network_interface($interface);
        $interface->detach();

Elastic Load Balancers (ELB)

       The methods in this section allow you to retrieve information about Elastic Load
       Balancers, create new ELBs, and change the properties of the ELBs.

       The primary object manipulated by these methods is VM::EC2::ELB. Please see the
       VM::EC2::ELB manual page

   @lbs = $ec2->describe_load_balancers(-load_balancer_name=>\@names)
   @lbs = $ec2->describe_load_balancers(@names)
       Provides detailed configuration information for the specified ELB(s).

       Optional parameters are:

           -load_balancer_names     Name of the ELB to return information on.
                                    This can be a string scalar, or an arrayref.

           -lb_name,-lb_names,
             -load_balancer_name    Aliases for -load_balancer_names

       Returns a series of VM::EC2::ELB objects.

   $success = $ec2->delete_load_balancer(-load_balancer_name=>$name)
   $success = $ec2->delete_load_balancer($name)
       Deletes the specified ELB.

       Arguments:

        -load_balancer_name    -- The name of the ELB to delete

        -lb_name               -- Alias for -load_balancer_name

       Returns true on successful deletion.  NOTE:  This API call will return success regardless
       of existence of the ELB.

   $healthcheck = $ec2->configure_health_check(-load_balancer_name  => $name, -healthy_threshold
       => $cnt, -interval            => $secs, -target              => $target, -timeout
       => $secs, -unhealthy_threshold => $cnt)
       Define an application healthcheck for the instances.

       All Parameters are required.

           -load_balancer_name    Name of the ELB.

           -healthy_threashold    Specifies the number of consecutive health probe successes
                                  required before moving the instance to the Healthy state.

           -interval              Specifies the approximate interval, in seconds, between
                                  health checks of an individual instance.

           -target                Must be a string in the form: Protocol:Port[/PathToPing]
                                   - Valid Protocol types are: HTTP, HTTPS, TCP, SSL
                                   - Port must be in range 1-65535
                                   - PathToPing is only applicable to HTTP or HTTPS protocol
                                     types and must be 1024 characters long or fewer.

           -timeout               Specifies the amount of time, in seconds, during which no
                                  response means a failed health probe.

           -unhealthy_threashold  Specifies the number of consecutive health probe failures
                                  required before moving the instance to the Unhealthy state.

           -lb_name               Alias for -load_balancer_name

       Returns a VM::EC2::ELB::HealthCheck object.

   $success = $ec2->create_app_cookie_stickiness_policy(-load_balancer_name => $name,
       -cookie_name        => $cookie, -policy_name        => $policy)
       Generates a stickiness policy with sticky session lifetimes that follow that of an
       application-generated cookie. This policy can be associated only with HTTP/HTTPS
       listeners.

       Required arguments:

           -load_balancer_name    Name of the ELB.

           -cookie_name           Name of the application cookie used for stickiness.

           -policy_name           The name of the policy being created. The name must
                                  be unique within the set of policies for this ELB.

           -lb_name               Alias for -load_balancer_name

       Returns true on successful execution.

   $success = $ec2->create_lb_cookie_stickiness_policy(-load_balancer_name       => $name,
       -cookie_expiration_period => $secs, -policy_name              => $policy)
       Generates a stickiness policy with sticky session lifetimes controlled by the lifetime of
       the browser (user-agent) or a specified expiration period. This policy can be associated
       only with HTTP/HTTPS listeners.

       Required arguments:

           -load_balancer_name         Name of the ELB.

           -cookie_expiration_period   The time period in seconds after which the
                                       cookie should be considered stale. Not
                                       specifying this parameter indicates that the
                                       sticky session will last for the duration of
                                       the browser session.  OPTIONAL

           -policy_name                The name of the policy being created. The name
                                       must be unique within the set of policies for
                                       this ELB.

           -lb_name                    Alias for -load_balancer_name

       Returns true on successful execution.

   $lb = $ec2->create_load_balancer(-load_balancer_name => $name, -listeners          =>
       \@listeners, -availability_zones => \@zones, -scheme             => $scheme, )
       Creates a new ELB.

       Required arguments:

           -load_balancer_name         Name of the ELB.

           -listeners                  Must either be a L<VM::EC2::ELB:Listener> object
                                       (or arrayref of objects) or a hashref (or arrayref
                                       of hashrefs) containing the following keys:

                     Protocol            -- Value as one of: HTTP, HTTPS, TCP, or SSL
                     LoadBalancerPort    -- Value in range 1-65535
                     InstancePort        -- Value in range 1-65535
                       and optionally:
                     InstanceProtocol    -- Value as one of: HTTP, HTTPS, TCP, or SSL
                     SSLCertificateId    -- Certificate ID from AWS IAM certificate list

           -availability_zones    Literal string or array of strings containing valid
                                  availability zones.  Optional if subnets are
                                  specified in a VPC usage scenario.

       Optional arguments:

           -scheme                The type of ELB.  By default, Elastic Load Balancing
                                  creates an Internet-facing LoadBalancer with a
                                  publicly resolvable DNS name, which resolves to
                                  public IP addresses.  Specify the value 'internal'
                                  for this option to create an internal LoadBalancer
                                  with a DNS name that resolves to private IP addresses.
                                  This option is only available in a VPC.

           -security_groups       The security groups assigned to your ELB within your
                                  VPC.  String or arrayref.

           -subnets               A list of subnet IDs in your VPC to attach to your
                                  ELB.  String or arrayref.  REQUIRED if availability
                                  zones are not specified above.

       Argument aliases:

           -zones                 Alias for -availability_zones
           -lb_name               Alias for -load_balancer_name

       Returns a VM::EC2::ELB object if successful.

   $success = $ec2->create_load_balancer_listeners(-load_balancer_name => $name, -listeners
       => \@listeners)
       Creates one or more listeners on a ELB for the specified port. If a listener with the
       given port does not already exist, it will be created; otherwise, the properties of the
       new listener must match the properties of the existing listener.

        -listeners    Must either be a L<VM::EC2::ELB:Listener> object (or arrayref of
                      objects) or a hash (or arrayref of hashes) containing the
                      following keys:

                    Protocol            -- Value as one of: HTTP, HTTPS, TCP, or SSL
                    LoadBalancerPort    -- Value in range 1-65535
                    InstancePort        -- Value in range 1-65535
                     and optionally:
                    InstanceProtocol    -- Value as one of: HTTP, HTTPS, TCP, or SSL
                    SSLCertificateId    -- Certificate ID from AWS IAM certificate list

        -lb_name      Alias for -load_balancer_name

       Returns true on successful execution.

   $success = $ec2->delete_load_balancer_listeners(-load_balancer_name  => $name,
       -load_balancer_ports => \@ports)
       Deletes listeners from the ELB for the specified port.

       Arguments:

        -load_balancer_name     The name of the ELB

        -load_balancer_ports    An arrayref of strings or literal string containing
                                the port numbers.

        -ports                  Alias for -load_balancer_ports

        -lb_name                Alias for -load_balancer_name

       Returns true on successful execution.

   @z = $ec2->disable_availability_zones_for_load_balancer(-load_balancer_name => $name,
       -availability_zones => \@zones)
       Removes the specified EC2 Availability Zones from the set of configured Availability Zones
       for the ELB.  There must be at least one Availability Zone registered with a LoadBalancer
       at all times.  Instances registered with the ELB that are in the removed Availability Zone
       go into the OutOfService state.

       Arguments:

        -load_balancer_name    The name of the ELB

        -availability_zones    Arrayref or literal string of availability zone names
                               (ie. us-east-1a)

        -zones                 Alias for -availability_zones

        -lb_name               Alias for -load_balancer_name

       Returns an array of VM::EC2::AvailabilityZone objects now associated with the ELB.

   @z = $ec2->enable_availability_zones_for_load_balancer(-load_balancer_name => $name,
       -availability_zones => \@zones)
       Adds one or more EC2 Availability Zones to the ELB.  The ELB evenly distributes requests
       across all its registered Availability Zones that contain instances.

       Arguments:

        -load_balancer_name    The name of the ELB

        -availability_zones    Array or literal string of availability zone names
                               (ie. us-east-1a)

        -zones                 Alias for -availability_zones

        -lb_name               Alias for -load_balancer_name

       Returns an array of VM::EC2::AvailabilityZone objects now associated with the ELB.

   @i = $ec2->register_instances_with_load_balancer(-load_balancer_name => $name, -instances
       => \@instance_ids)
       Adds new instances to the ELB.  If the instance is in an availability zone that is not
       registered with the ELB will be in the OutOfService state.  Once the zone is added to the
       ELB the instance will go into the InService state.

       Arguments:

        -load_balancer_name    The name of the ELB

        -instances             An arrayref or literal string of Instance IDs.

        -lb_name               Alias for -load_balancer_name

       Returns an array of instances now associated with the ELB in the form of VM::EC2::Instance
       objects.

   @i = $ec2->deregister_instances_from_load_balancer(-load_balancer_name => $name, -instances
       => \@instance_ids)
       Deregisters instances from the ELB. Once the instance is deregistered, it will stop
       receiving traffic from the ELB.

       Arguments:

        -load_balancer_name    The name of the ELB

        -instances             An arrayref or literal string of Instance IDs.

        -lb_name               Alias for -load_balancer_name

       Returns an array of instances now associated with the ELB in the form of VM::EC2::Instance
       objects.

   $success = $ec2->set_load_balancer_listener_ssl_certificate(-load_balancer_name => $name,
       -load_balancer_port => $port, -ssl_certificate_id => $cert_id)
       Sets the certificate that terminates the specified listener's SSL connections.  The
       specified certificate replaces any prior certificate that was used on the same ELB and
       port.

       Required arguments:

        -load_balancer_name    The name of the the ELB.

        -load_balancer_port    The port that uses the specified SSL certificate.

        -ssl_certificate_id    The ID of the SSL certificate chain to use.  See the
                               AWS Identity and Access Management documentation under
                               Managing Server Certificates for more information.

       Alias arguments:

        -lb_name    Alias for -load_balancer_name

        -port       Alias for -load_balancer_port

        -cert_id    Alias for -ssl_certificate_id

       Returns true on successful execution.

   @states = $ec2->describe_instance_health(-load_balancer_name => $name, -instances          =>
       \@instance_ids)
       Returns the current state of the instances of the specified LoadBalancer. If no instances
       are specified, the state of all the instances for the ELB is returned.

       Required arguments:

           -load_balancer_name     The name of the ELB

       Optional parameters:

           -instances              Literal string or arrayref of Instance IDs

           -lb_name                Alias for -load_balancer_name

           -instance_id            Alias for -instances

       Returns an array of VM::EC2::ELB::InstanceState objects.

   $success = $ec2->create_load_balancer_policy(-load_balancer_name => $name, -policy_name
       => $policy, -policy_type_name   => $type_name, -policy_attributes  => \@attrs)
       Creates a new policy that contains the necessary attributes depending on the policy type.
       Policies are settings that are saved for your ELB and that can be applied to the front-end
       listener, or the back-end application server, depending on your policy type.

       Required Arguments:

        -load_balancer_name   The name associated with the LoadBalancer for which the
                              policy is being created. This name must be unique within
                              the client AWS account.

        -policy_name          The name of the ELB policy being created. The name must
                              be unique within the set of policies for this ELB.

        -policy_type_name     The name of the base policy type being used to create
                              this policy. To get the list of policy types, use the
                              describe_load_balancer_policy_types function.

       Optional Arguments:

        -policy_attributes    Arrayref of hashes containing AttributeName and AttributeValue

        -lb_name              Alias for -load_balancer_name

       Returns true if successful.

   $success = $ec2->delete_load_balancer_policy(-load_balancer_name => $name, -policy_name
       => $policy)
       Deletes a policy from the ELB. The specified policy must not be enabled for any listeners.

       Arguments:

        -load_balancer_name    The name of the ELB

        -policy_name           The name of the ELB policy

        -lb_name               Alias for -load_balancer_name

       Returns true if successful.

   @policy_descs = $ec2->describe_load_balancer_policies(-load_balancer_name => $name,
       -policy_names       => \@names)
       Returns detailed descriptions of ELB policies. If you specify an ELB name, the operation
       returns either the descriptions of the specified policies, or descriptions of all the
       policies created for the ELB. If you don't specify a ELB name, the operation returns
       descriptions of the specified sample policies, or descriptions of all the sample policies.
       The names of the sample policies have the ELBSample- prefix.

       Optional Arguments:

        -load_balancer_name  The name of the ELB.

        -policy_names        The names of ELB policies created or ELB sample policy names.

        -lb_name             Alias for -load_balancer_name

       Returns an array of VM::EC2::ELB::PolicyDescription objects if successful.

   @policy_types = $ec2->describe_load_balancer_policy_types(-policy_type_names => \@names)
       Returns meta-information on the specified ELB policies defined by the Elastic Load
       Balancing service. The policy types that are returned from this action can be used in a
       create_load_balander_policy call to instantiate specific policy configurations that will
       be applied to an ELB.

       Required arguemnts:

        -load_balancer_name    The name of the ELB.

       Optional arguments:

        -policy_type_names    Literal string or arrayref of policy type names

        -names                Alias for -policy_type_names

       Returns an array of VM::EC2::ELB::PolicyTypeDescription objects if successful.

   $success = $ec2->set_load_balancer_policies_of_listener(-load_balancer_name => $name,
       -load_balancer_port => $port, -policy_names       => \@names)
       Associates, updates, or disables a policy with a listener on the ELB.  Multiple policies
       may be associated with a listener.

       Required arguments:

        -load_balancer_name    The name associated with the ELB.

        -load_balancer_port    The external port of the LoadBalancer with which this
                               policy applies to.

        -policy_names          List of policies to be associated with the listener.
                               Currently this list can have at most one policy. If the
                               list is empty, the current policy is removed from the
                               listener.  String or arrayref.

       Returns true if successful.

   @sgs = $ec2->apply_security_groups_to_load_balancer(-load_balancer_name => $name,
       -security_groups    => \@groups)
       Associates one or more security groups with your ELB in VPC.  The provided security group
       IDs will override any currently applied security groups.

       Required arguments:

        -load_balancer_name The name associated with the ELB.

        -security_groups    A list of security group IDs to associate with your ELB in
                            VPC. The security group IDs must be provided as the ID and
                            not the security group name (For example, sg-123456).
                            String or arrayref.

       Returns a series of VM::EC2::SecurityGroup objects.

   @subnets = $ec2->attach_load_balancer_to_subnets(-load_balancer_name => $name, -subnets
       => \@subnets)
       Adds one or more subnets to the set of configured subnets for the ELB.

       Required arguments:

        -load_balancer_name    The name associated with the ELB.

        -subnets               A list of subnet IDs to add for the ELB.  String or
                               arrayref.

       Returns a series of VM::EC2::VPC::Subnet objects corresponding to the subnets the ELB is
       now attached to.

   @subnets = $ec2->detach_load_balancer_from_subnets(-load_balancer_name => $name, -subnets
       => \@subnets)
       Removes subnets from the set of configured subnets in the VPC for the ELB.

       Required arguments:

        -load_balancer_name    The name associated with the ELB.

        -subnets               A list of subnet IDs to add for the ELB.  String or
                               arrayref.

       Returns a series of VM::EC2::VPC::Subnet objects corresponding to the subnets the ELB is
       now attached to.

   $success = $ec2->set_load_balancer_policies_for_backend_server(-instance_port      => $port,
       -load_balancer_name => $name, -policy_names       => \@policies)
       Replaces the current set of policies associated with a port on which the back- end server
       is listening with a new set of policies. After the policies have been created, they can be
       applied here as a list.  At this time, only the back- end server authentication policy
       type can be applied to the back-end ports; this policy type is composed of multiple public
       key policies.

       Required arguments:

        -load_balancer_name    The name associated with the ELB.

        -instance_port         The port number associated with the back-end server.

        -policy_names          List of policy names to be set. If the list is empty,
                               then all current polices are removed from the back-end
                               server.

       Aliases:

        -port      Alias for -instance_port
        -lb_name   Alias for -load_balancer_name

       Returns true if successful.

AWS SECURITY TOKENS

       AWS security tokens provide a way to grant temporary access to resources in your EC2 space
       without giving them permanent accounts. They also provide the foundation for mobile
       services and multifactor authentication devices (MFA).

       Used in conjunction with VM::EC2::Security::Policy and VM::EC2::Security::Credentials, you
       can create a temporary user who is authenticated for a limited length of time and pass the
       credentials to him or her via a secure channel. He or she can then create a credentials
       object to access your AWS resources.

       Here is an example:

        # on your side of the connection
        $ec2 = VM::EC2->new(...);  # as usual
        my $policy = VM::EC2::Security::Policy->new;
        $policy->allow('DescribeImages','RunInstances');
        my $token = $ec2->get_federation_token(-name     => 'TemporaryUser',
                                               -duration => 60*60*3, # 3 hrs, as seconds
                                               -policy   => $policy);
        my $serialized = $token->credentials->serialize;
        send_data_to_user_somehow($serialized);

        # on the temporary user's side of the connection
        my $serialized = get_data_somehow();
        my $token = VM::EC2::Security::Credentials->new_from_serialized($serialized);
        my $ec2   = VM::EC2->new(-security_token => $token);
        print $ec2->describe_images(-owner=>'self');

       For temporary users who are not using the Perl VM::EC2 API, you can transmit the required
       fields individually:

        my $credentials   = $token->credentials;
        my $access_key_id = $credentials->accessKeyId;
        my $secret_key    = $credentials->secretKey;
        my $session_token = $credentials->sessionToken;
        send_data_to_user_somehow($session_token,
                                  $access_key_id,
                                  $secret_key);

       Calls to get_federation_token() return a VM::EC2::Security::Token object. This object
       contains two sub-objects, a VM::EC2::Security::Credentials object, and a
       VM::EC2::Security::FederatedUser object. The Credentials object contains a temporary
       access key ID, secret access key, and session token which together can be used to
       authenticate to the EC2 API.  The FederatedUser object contains the temporary user account
       name and ID.

       See VM::EC2::Security::Token, VM::EC2::Security::FederatedUser,
       VM::EC2::Security::Credentials, and VM::EC2::Security::Policy.

   $token = $ec2->get_federation_token($username)
   $token = $ec2->get_federation_token(-name=>$username,@args)
       This method creates a new temporary user under the provided username and returns a
       VM::EC2::Security::Token object that contains temporary credentials for the user, as well
       as information about the user's account. Other options allow you to control the duration
       for which the credentials will be valid, and the policy the controls what resources the
       user is allowed to access.

       Required arguments:
            -name The username

           The username must comply with the guidelines described in
           http://docs.amazonwebservices.com/IAM/latest/UserGuide/LimitationsOnEntities.html:
           essentially all alphanumeric plus the characters [+=,.@-].

       Optional arguments:
            -duration_seconds Length of time the session token will be valid for,
                               expressed in seconds.

            -duration         Same thing, faster to type.

            -policy           A VM::EC2::Security::Policy object, or a JSON string
                                complying with the IAM policy syntax.

           The duration must be no shorter than 1 hour (3600 seconds) and no longer than 36 hours
           (129600 seconds). If no duration is specified, Amazon will default to 12 hours. If no
           policy is provided, then the user will not be able to execute any actions.

           Note that if the temporary user wishes to create a VM::EC2 object and specify a region
           name at create time (e.g. VM::EC2->new(-region=>'us-west-1'), then the user must have
           access to the DescribeRegions action:

            $policy->allow('DescribeRegions')

           Otherwise the call to new() will fail.

   $token = $ec2->get_session_token(%args)
       This method creates a temporary VM::EC2::Security::Token object for an anonymous user. The
       token has no policy associated with it, and can be used to run any of the EC2 actions
       available to the user who created the token. Optional arguments allow the session token to
       be used in conjunction with MFA devices.

       Required arguments:
           none

       Optional arguments:
            -duration_seconds Length of time the session token will be valid for,
                               expressed in seconds.

            -duration         Same thing, faster to type.

            -serial_number    The identification number of the user's MFA device,
                                if any.

            -token_code       The code provided by the MFA device, if any.

           If no duration is specified, Amazon will default to 12 hours.

           See http://docs.amazonwebservices.com/IAM/latest/UserGuide/Using_ManagingMFA.html for
           information on using AWS in conjunction with MFA devices.

LAUNCH CONFIGURATIONS

   @lc = $ec2->describe_launch_configurations(-names => \@names);
   @lc = $ec->describe_launch_configurations(@names);
       Provides detailed information for the specified launch configuration(s).

       Optional parameters are:

         -launch_configuration_names   Name of the Launch config.
                                         This can be a string scalar or an arrayref.

         -name  Alias for -launch_configuration_names

       Returns a series of VM::EC2::LaunchConfiguration objects.

   $success = $ec2->create_launch_configuration(%args);
       Creates a new launch configuration.

       Required arguments:

         -name           -- scalar, name for the Launch config.
         -image_id       -- scalar, AMI id which this launch config will use
         -instance_type  -- scalar, instance type of the Amazon EC2 instance.

       Optional arguments:

         -block_device_mappings  -- list of hashref
         -ebs_optimized          -- scalar (boolean). false by default
         -iam_instance_profile   -- scalar
         -instance_monitoring    -- scalar (boolean). true by default
         -kernel_id              -- scalar
         -key_name               -- scalar
         -ramdisk                -- scalar
         -security_groups        -- list of scalars
         -spot_price             -- scalar
         -user_data              -- scalar

       Returns true on successful execution.

   $success = $ec2->delete_launch_configuration(-name => $name);
       Deletes a launch config.

         -name     Required. Name of the launch config to delete

       Returns true on success.

AUTOSCALING GROUPS

   @asg = $ec2->describe_autoscaling_groups(-auto_scaling_group_names => \@names);
       Returns information about autoscaling groups

         -auto_scaling_group_names     List of auto scaling groups to describe
         -names                        Alias of -auto_scaling_group_names

       Returns a list of VM::EC2::ASG.

   $success = $ec2->create_autoscaling_group(-name => $name, -launch_config => $lc, -max_size =>
       $max_size, -min_size => $min_size);
       Creates a new autoscaling group.

       Required arguments:

         -name             Name for the autoscaling group
         -launch_config    Name of the launch configuration to be used
         -max_size         Max number of instances to be run at once
         -min_size         Min number of instances

       Optional arguments:

         -availability_zones   List of availability zone names
         -load_balancer_names  List of ELB names
         -tags                 List of tags to apply to the instances run
         -termination_policies List of policy names
         -default_cooldown     Time in seconds between autoscaling activities
         -desired_capacity     Number of instances to be run after creation
         -health_check_type    One of "ELB" or "EC2"
         -health_check_grace_period    Mandatory for health check type ELB. Number of
                                       seconds between an instance is started and the
                                       autoscaling group starts checking its health
         -placement_group      Physical location of your cluster placement group
         -vpc_zone_identifier  Strinc containing a comma-separated list of subnet
                               identifiers

       Returns true on success.

   $success = $ec2->delete_autoscaling_group(-name => $name)
       Deletes an autoscaling group.

         -name     Name of the autoscaling group to delete

       Returns true on success.

   $success = $ec2->update_autoscaling_group(-name => $name);
       Updates an autoscaling group. Only required parameter is "-name"

       Optional arguments:

         -availability_zones       List of AZ's
         -termination_policies     List of policy names
         -default_cooldown
         -desired_capacity
         -health_check_type
         -health_check_grace_period
         -placement_group
         -vpc_zone_identifier
         -max_size
         -min_size

       Returns true on success;

   $success = $ec2->suspend_processes(-name => $asg_name, -scaling_processes => \@procs);
       Suspend the requested autoscaling processes.

         -name                 Name of the autoscaling group
         -scaling_processes    List of process names to suspend. Valid processes are:
               Launch
               Terminate
               HealthCheck
               ReplaceUnhealty
               AZRebalance
               AlarmNotification
               ScheduledActions
               AddToLoadBalancer

       Returns true on success.

   $success = $ec2->resume_processes(-name => $asg_name, -scaling_processes => \@procs);
       Resumes the requested autoscaling processes. It accepts the same arguments than
       "suspend_processes".

       Returns true on success.

INTERNAL METHODS

       These methods are used internally and are listed here without documentation (yet).

   $underscore_name = $ec2->canonicalize($mixedCaseName)
   $instance_id = $ec2->instance_parm(@args)
   @arguments = $ec2->value_parm(ParameterName => \%args)
   @arguments = $ec2->single_parm(ParameterName => \%args)
   @parameters = $ec2->prefix_parm($prefix, ParameterName => \%args)
   @parameters = $ec2->member_list_parm(ParameterName => \%args)
   @arguments = $ec2->list_parm(ParameterName => \%args)
   @arguments = $ec2->autoscaling_tags($argname, \%args)
   @arguments = $ec2->filter_parm(\%args)
   @arguments = $ec2->tagcreate_parm(\%args)
   @arguments = $ec2->tagdelete_parm(\%args)
   @arguments =
       $ec2->key_value_parameters($param_name,$keyname,$valuename,\%args,$skip_undef_values)
   @arguments = $ec2->launch_perm_parm($prefix,$suffix,$value)
   @arguments = $ec2->iam_parm($args)
   @arguments = $ec2->block_device_parm($block_device_mapping_string)
   $version = $ec2->version()
       API version.

   $ts = $ec2->timestamp
   $ua = $ec2->ua
       LWP::UserAgent object.

   @obj = $ec2->call($action,@param);
       Make a call to Amazon using $action and the passed arguments, and return a list of
       objects.

   $request = $ec2->make_request($action,@param);
       Set up the signed HTTP::Request object.

   $request = $ec2->_sign(@args)
       Create and sign an HTTP::Request.

   @param = $ec2->args(ParamName=>@_)
       Set up calls that take either method(-resource_id=>'foo') or method('foo').

MISSING METHODS

       As of 24 Dec 2012, the following Amazon API calls were NOT implemented. Volunteers to
       implement these calls are most welcome.

       BundleInstance CancelBundleTask CancelConversionTask CancelReservedInstancesListing
       CreateReservedInstancesListing DescribeBundleTasks DescribeConversionTasks
       DescribeReservedInstancesListings ImportInstance ImportVolume

OTHER INFORMATION

       This section contains technical information that may be of interest to developers.

   Signing and authentication protocol
       This module uses Amazon AWS signing protocol version 2, as described at
       http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/index.html?using-query-api.html.
       It uses the HmacSHA256 signature method, which is the most secure method currently
       available. For additional security, use "https" for the communications endpoint:

         $ec2 = VM::EC2->new(-endpoint=>'https://ec2.amazonaws.com');

   Subclassing VM::EC2 objects
       To subclass VM::EC2 objects (or implement your own from scratch) you will need to override
       the object dispatch mechanism. Fortunately this is very easy. After "use VM::EC2" call
       VM::EC2::Dispatch->add_override() one or more times:

        VM::EC2::Dispatch->add_override($call_name => $dispatch).

       The first argument, $call_name, is name of the Amazon API call, such as "DescribeImages".

       The second argument, $dispatch, instructs VM::EC2::Dispatch how to create objects from the
       parsed XML. There are three possible syntaxes:

        1) A CODE references, such as an anonymous subroutine.

           In this case the code reference will be invoked to handle the
           parsed XML returned from the request. The code will receive
           two arguments consisting of the parsed
           content of the response, and the VM::EC2 object used to generate the
           request.

        2) A VM::EC2::Dispatch method name, optionally followed by its arguments
           delimited by commas. Example:

                  "fetch_items,securityGroupInfo,VM::EC2::SecurityGroup"

           This tells Dispatch to invoke its fetch_items() method with
           the following arguments:

            $dispatch->fetch_items($parsed_xml,$ec2,'securityGroupInfo','VM::EC2::SecurityGroup')

           The fetch_items() method is used for responses in which a
           list of objects is embedded within a series of <item> tags.
           See L<VM::EC2::Dispatch> for more information.

           Other commonly-used methods are "fetch_one", and "boolean".

        3) A class name, such as 'MyVolume'

           In this case, class MyVolume is loaded and then its new() method
           is called with the four arguments ($parsed_xml,$ec2,$xmlns,$requestid),
           where $parsed_xml is the parsed XML response, $ec2 is the VM::EC2
           object that generated the request, $xmlns is the XML namespace
           of the XML response, and $requestid is the AWS-generated ID for the
           request. Only the first two arguments are really useful.

           I suggest you inherit from VM::EC2::Generic and use the inherited new()
           method to store the parsed XML object and other arguments.

       Dispatch tries each of (1), (2) and (3), in order. This means that class names cannot
       collide with method names.

       The parsed content is the result of passing the raw XML through a XML::Simple object
       created with:

        XML::Simple->new(ForceArray    => ['item'],
                         KeyAttr       => ['key'],
                         SuppressEmpty => undef);

       In general, this will give you a hash of hashes. Any tag named 'item' will be forced to
       point to an array reference, and any tag named "key" will be flattened as described in the
       XML::Simple documentation.

       A simple way to examine the raw parsed XML is to invoke any VM::EC2::Generic's as_string()
       method:

        my ($i) = $ec2->describe_instances;
        print $i->as_string;

       This will give you a Data::Dumper representation of the XML after it has been parsed.

       The suggested way to override the dispatch table is from within a subclass of VM::EC2:

        package 'VM::EC2New';
        use base 'VM::EC2';
         sub new {
             my $self=shift;
             VM::EC2::Dispatch->add_override('call_name_1'=>\&subroutine1).
             VM::EC2::Dispatch->add_override('call_name_2'=>\&subroutine2).
             $self->SUPER::new(@_);
        }

       See VM::EC2::Dispatch for a working example of subclassing VM::EC2 and one of its object
       classes.

DEVELOPING

       The git source for this library can be found at https://github.com/lstein/LibVM-EC2-Perl,
       To contribute to development, please obtain a github account and then either:

        1) Fork a copy of the repository, make your changes against this repository,
           and send a pull request to me to incorporate your changes.

        2) Contact me by email and ask for push privileges on the repository.

       See http://help.github.com/ for help getting started.

SEE ALSO

       Net::Amazon::EC2 VM::EC2::Dispatch VM::EC2::Generic VM::EC2::BlockDevice
       VM::EC2::BlockDevice::Attachment VM::EC2::BlockDevice::EBS VM::EC2::BlockDevice::Mapping
       VM::EC2::BlockDevice::Mapping::EBS VM::EC2::Error VM::EC2::Generic VM::EC2::Group
       VM::EC2::Image VM::EC2::Instance VM::EC2::Instance::ConsoleOutput
       VM::EC2::Instance::Metadata VM::EC2::Instance::MonitoringState
       VM::EC2::Instance::PasswordData VM::EC2::Instance::Set VM::EC2::Instance::State
       VM::EC2::Instance::State::Change VM::EC2::Instance::State::Reason VM::EC2::KeyPair
       VM::EC2::Region VM::EC2::ReservationSet VM::EC2::ReservedInstance
       VM::EC2::ReservedInstance::Offering VM::EC2::SecurityGroup VM::EC2::Snapshot
       VM::EC2::Staging::Manager VM::EC2::Tag VM::EC2::Volume

AUTHOR

       Lincoln Stein <lincoln.stein@gmail.com>.

       Copyright (c) 2011 Ontario Institute for Cancer Research

       This package and its accompanying libraries is free software; you can redistribute it
       and/or modify it under the terms of the GPL (either version 1, or at your option, any
       later version) or the Artistic License 2.0.  Refer to LICENSE for the full license text.
       In addition, please see DISCLAIMER.txt for disclaimers of warranty.