Provided by: libvm-ec2-perl_1.28-2build1_all 
NAME
VM::EC2 - Perl interface to Amazon EC2, Virtual Private Cloud, Elastic Load Balancing,
Autoscaling, and Relational Database services
SYNOPSIS
NOTE: For information on AWS's VPC, load balancing, autoscaling and relational databases
services, see VM::EC2::VPC, VM::EC2::ELB, VM::EC2::REST::autoscaling, and
VM::EC2::REST::relational_database_service
# 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 2014-05-01 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
Open Stack open source cloud (http://www.openstack.org/).
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.
ASYNCHRONOUS CALLS
As of version 1.24, VM::EC2 supports asynchronous calls to AWS using AnyEvent::HTTP. This
allows you to make multiple calls in parallel for a significant improvement in
performance.
In asynchronous mode, VM::EC2 calls that ordinarily wait for AWS to respond and then
return objects corresponding to EC2 instances, volumes, images, and so forth, will instead
immediately return an AnyEvent condition variable. You can retrieve the result of the call
by calling the condition variable's recv() method, or by setting a callback to be executed
when the call is complete.
To make an asynchronous call, you can set the global variable $VM::EC2::ASYNC to a true
value
Here is an example of a normal synchronous call:
my @instances = $ec2->describe_instances();
Here is the asynchronous version initiated after setting $VM::EC2::ASYNC (using a local
block to limit its effects).
{
local $VM::EC2::ASYNC=1;
my $cv = $ec2->describe_instances(); # returns immediately
my @instances = $cv->recv;
}
In case of an error recv() will return undef and the error object can be recovered using
the condition variable's error() method (this is an enhancement over AnyEvent's standard
condition variable class):
my @instances = $cv->recv
or die "No instances found! error = ",$cv->error();
You may attach a callback CODE reference to the condition variable using its cb() method,
in which case the callback will be invoked when the APi call is complete. The callback
will be invoked with a single argument consisting of the condition variable. Ordinarily
you will call recv() on the variable and then do something with the result:
{
local $VM::EC2::ASYNC=1;
my $cv = $ec2->describe_instances();
$cv->cb(sub {my $v = shift;
my @i = $v->recv;
print "instances = @i\n";
});
}
For callbacks to be invoked, someone must be run an event loop using one of the event
frameworks that AnyEvent supports (e.g. Coro, Tk or Gtk). Alternately, you may simply run:
AnyEvent->condvar->recv();
If $VM::EC2::ASYNC is false, you can issue a single asynchronous call by appending
"_async" to the name of the method call. Similarly, if $VM::EC2::ASYNC is true, you can
make a single normal synchrous call by appending "_sync" to the method name.
For example, this is equivalent to the above:
my $cv = $ec2->describe_instances_async(); # returns immediately
my @instances = $cv->recv;
You may stack multiple asynchronous calls on top of one another. When you call recv() on
any of the returned condition variables, they will all run in parallel. Hence the three
calls will take no longer than the longest individual one:
my $cv1 = $ec2->describe_instances_async({'instance-state-name'=>'running'});
my $cv2 = $ec2->describe_instances_async({'instance-state-name'=>'stopped'});
my @running = $cv1->recv;
my @stopped = $cv2->recv;
Same thing with callbacks:
my (@running,@stopped);
my $cv1 = $ec2->describe_instances_async({'instance-state-name'=>'running'});
$cv1->cb(sub {@running = shift->recv});
my $cv2 = $ec2->describe_instances_async({'instance-state-name'=>'stopped'});
$cv1->cb(sub {@stopped = shift->recv});
AnyEvent->condvar->recv;
And here it is using a group conditional variable to block until all pending
describe_instances() requests have completed:
my %instances;
my $group = AnyEvent->condvar;
$group->begin;
for my $state (qw(pending running stopping stopped)) {
$group->begin;
my $cv = $ec2->describe_instances_async({'instance-state-name'=>$state});
$cv->cb(sub {my @i = shift->recv;
$instances{$state}=\@i;
$group->end});
}
$group->recv;
# when we get here %instances will be populated by all instances,
# sorted by their state.
If this looks mysterious, please consult AnyEvent for full documentation and examples.
Lastly, be advised that some of the objects returned by calls to VM::EC2, such as the
VM::EC2::Instance object, will make their own calls into VM::EC2 for certain methods. Some
of these methods will block (be synchronous) of necessity, even if you have set
$VM::EC2::ASYNC. For example, the instance object's current_status() method must block in
order to update the object and return the current status. Other object methods may behave
unpredictably in async mode. Caveat emptor!
API GROUPS
The extensive (and growing) Amazon API has many calls that you may never need. To avoid
the performance overhead of loading the interfaces to all these calls, you may use Perl's
import mechanism to load only those modules you care about. By default, all methods are
loaded.
Loading is controlled by the "use" import list, and follows the conventions described in
the Exporter module:
use VM::EC2; # load all methods!
use VM::EC2 'key','elastic_ip'; # load Key Pair and Elastic IP
# methods only
use VM::EC2 ':standard'; # load all the standard methods
use VM::EC2 ':standard','!key'; # load standard methods but not Key Pair
Related API calls are grouped together using the scheme described at
http://docs.aws.amazon.com/AWSEC2/latest/APIReference/OperationList-query.html. The
modules that define the API calls can be found in VM/EC2/REST/; you can read their
documentation by running perldoc VM::EC2::REST::"name of module":
perldoc VM::EC2::REST::elastic_ip
The groups that you can import are as follows:
:standard => ami, ebs, elastic_ip, instance, keys, general,
monitoring, tag, security_group, security_token, zone
:vpc => customer_gateway, dhcp, elastic_network_interface,
private_ip, internet_gateway, network_acl, route_table,
vpc, vpn, vpn_gateway
:misc => devpay, monitoring, reserved_instance,
spot_instance, vm_export, vm_import, windows
:scaling => elastic_load_balancer,autoscaling
:hpc => placement_group
:all => :standard, :vpn, :misc
:DEFAULT => :all
The individual modules are:
ami -- Control Amazon Machine Images
autoscaling -- Control autoscaling
customer_gateway -- VPC/VPN gateways
devpay -- DevPay API
dhcp -- VPC DHCP options
ebs -- Elastic Block Store volumes & snapshots
elastic_ip -- Elastic IP addresses
elastic_load_balancer -- The Elastic Load Balancer service
elastic_network_interface -- VPC Elastic Network Interfaces
general -- Get console output and account attributes
instance -- Control EC2 instances
internet_gateway -- VPC connections to the internet
keys -- Manage SSH keypairs
monitoring -- Control instance monitoring
network_acl -- Control VPC network access control lists
placement_group -- Control the placement of HPC instances
private_ip -- VPC private IP addresses
reserved_instance -- Reserve instances and view reservations
route_table -- VPC network routing
security_group -- Security groups for VPCs and normal instances
security_token -- Temporary credentials for use with IAM roles
spot_instance -- Request and manage spot instances
subnet -- VPC subnets
tag -- Create and interrogate resource tags.
vm_export -- Export VMs
vm_import -- Import VMs
vpc -- Create and manipulate virtual private clouds
vpn_gateway -- Create and manipulate VPN gateways within VPCs
vpn -- Create and manipulate VPNs within VPCs
windows -- Windows operating system-specific API calls.
zone -- Interrogate availability zones
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 an Open Stack 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');
INSTANCES
Load the 'instances' module to bring in methods for interrogating, launching and
manipulating EC2 instances. This module is part of the ':standard' API group. The methods
are described in detail in VM::EC2::REST::instance. Briefly:
@i = $ec2->describe_instances(-instance_id=>\@ids,-filter=>\%filters)
@i = $ec2->run_instances(-image_id=>$id,%other_args)
@s = $ec2->start_instances(-instance_id=>\@instance_ids)
@s = $ec2->stop_instances(-instance_id=>\@instance_ids,-force=>1)
@s = $ec2->reboot_instances(-instance_id=>\@instance_ids)
$b = $ec2->confirm_product_instance($instance_id,$product_code)
$m = $ec2->instance_metadata
@d = $ec2->describe_instance_attribute($instance_id,$attribute)
$b = $ec2->modify_instance_attribute($instance_id,-$attribute_name=>$value)
$b = $ec2->reset_instance_attribute($instance_id,$attribute)
@s = $ec2->describe_instance_status(-instance_id=>\@ids,-filter=>\%filters,%other_args);
VOLUMES
Load the 'ebs' module to bring in methods specific for elastic block storage volumes and
snapshots. This module is part of the ':standard' API group. The methods are described in
detail in VM::EC2::REST::ebs. Briefly:
@v = $ec2->describe_volumes(-volume_id=>\@ids,-filter=>\%filters)
$v = $ec2->create_volume(%args)
$b = $ec2->delete_volume($volume_id)
$a = $ec2->attach_volume($volume_id,$instance_id,$device)
$a = $ec2->detach_volume($volume_id)
$ec2->wait_for_attachments(@attachment)
@v = $ec2->describe_volume_status(-volume_id=>\@ids,-filter=>\%filters)
$ec2->wait_for_volumes(@volumes)
@d = $ec2->describe_volume_attribute($volume_id,$attribute)
$b = $ec2->enable_volume_io(-volume_id=>$volume_id)
@s = $ec2->describe_snapshots(-snapshot_id=>\@ids,%other_args)
@d = $ec2->describe_snapshot_attribute($snapshot_id,$attribute)
$b = $ec2->modify_snapshot_attribute($snapshot_id,-$argument=>$value)
$b = $ec2->reset_snapshot_attribute($snapshot_id,$attribute)
$s = $ec2->create_snapshot(-volume_id=>$vol,-description=>$desc)
$b = $ec2->delete_snapshot($snapshot_id)
$s = $ec2->copy_snapshot(-source_region=>$region,-source_snapshot_id=>$id,-description=>$desc)
$ec2->wait_for_snapshots(@snapshots)
AMAZON MACHINE IMAGES
Load the 'ami' module to bring in methods for creating and manipulating Amazon Machine
Images. This module is part of the ':standard" group. Full details are in
VM::EC2::REST::ami. Briefly:
@i = $ec2->describe_images(@image_ids)
$i = $ec2->create_image(-instance_id=>$id,-name=>$name,%other_args)
$i = $ec2->register_image(-name=>$name,%other_args)
$r = $ec2->deregister_image($image_id)
@d = $ec2->describe_image_attribute($image_id,$attribute)
$b = $ec2->modify_image_attribute($image_id,-$attribute_name=>$value)
$b = $ec2->reset_image_attribute($image_id,$attribute_name)
KEYS
Load the 'keys' module to bring in methods for creating and manipulating SSH keypairs.
This module is loaded with the ':standard' group and documented in VM::EC2::REST::keys.
@k = $ec2->describe_key_pairs(@names);
$k = $ec2->create_key_pair($name)
$k = $ec2->import_key_pair($name,$public_key)
$b = $ec2->delete_key_pair($name)
TAGS
The methods in this module (loaded with ':standard') 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, and
VM::EC2::REST::tag for methods that allow you to manipulate the tags on multiple objects
simultaneously. The methods defined by this module are:
@t = $ec2->describe_tags(-filter=>\%filters);
$b = $ec2->create_tags(-resource_id=>\@ids,-tag=>{key1=>value1...})
$b = $ec2->delete_tags(-resource_id=>$id1,-tag=>{key1=>value1...})
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-related methods are defined in the customer_gateway, dhcp,
elastic_network_interface, private_ip, internet_gateway, network_acl, route_table, vpc,
vpn, and vpn_gateway modules, and are loaded by importing ':vpc'. See VM::EC2::REST::vpc
for an introduction.
The VM::EC2::VPC and VM::EC2::VPC::Subnet modules define convenience methods that simplify
working with VPC objects. 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;
ELASTIC LOAD BALANCERS (ELB) AND AUTOSCALING
The methods in the 'elastic_load_balancer' and 'autoscaling' modules allow you to retrieve
information about Elastic Load Balancers, create new ELBs, and change the properties of
the ELBs, as well as define autoscaling groups and their launch configurations. These
modules are both imported by the ':scaling' import group. See
VM::EC2::REST::elastic_load_balancer and VM::EC2::REST::autoscaling for descriptions of
the facilities enabled by this module.
AWS SECURITY POLICY
The VM::EC2::Security::Policy module provides a simple Identity and Access Management
(IAM) policy statement generator geared for use with AWS security tokens (see next
section). Its facilities are defined in VM::EC2::Security::Token.
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). These methods are defined in
'security_token', which is part of the ':standard' group. See
VM::EC2::REST::security_token for details. Here is a quick example:
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');
SPOT AND RESERVED INSTANCES
The 'spot_instance' and 'reserved_instance' modules allow you to create and manipulate
spot and reserved instances. They are both part of the ':misc' import group. See
VM::EC2::REST::spot_instance and VM::EC2::REST::reserved_instance. For example:
@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";
WAITING FOR STATE CHANGES
VM::EC2 provides a series of methods that allow your script to wait in an efficient manner
for desired state changes in instances, volumes and other objects. They are described in
detail the individual modules to which they apply, but in each case the method will block
until each member of a list of objects transitions to a terminal state (e.g. "completed"
in the case of a snapshot). Briefly:
$ec2->wait_for_instances(@instances)
$ec2->wait_for_snapshots(@snapshots)
$ec2->wait_for_volumes(@volumes)
$ec2->wait_for_attachments(@attachment)
There is also a generic version of this defined in the VM::EC2 core:
$ec2->wait_for_terminal_state(\@objects,['list','of','states'] [,$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.
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)
@arguments = $ec2->member_hash_parms(ParameterName => \%args)
Create a parameter list from a hashref or arrayref of hashes
Created specifically for the RDS ModifyDBParameterGroup parameter 'Parameters', but may be
useful for other calls in the future.
ie:
The argument would be in the form:
[
{
ParameterName=>'max_user_connections',
ParameterValue=>24,
ApplyMethod=>'pending-reboot'
},
{
ParameterName=>'max_allowed_packet',
ParameterValue=>1024,
ApplyMethod=>'immediate'
},
];
The resulting output would be if the argname is '-parameters':
Parameters.member.1.ParameterName => max_user_connections
Parameters.member.1.ParameterValue => 24 Parameters.member.1.ApplyMethod => pending-reboot
Parameters.member.2.ParameterName => max_allowed_packet Parameters.member.2.ParameterValue
=> 1024 Parameters.member.2.ApplyMethod => immediate
@arguments = $ec2->list_parm(ParameterName => \%args)
@parameters = $ec2->member_list_parm(ParameterName => \%args)
@arguments = $ec2->filter_parm(\%args)
@arguments =
$ec2->key_value_parameters($param_name,$keyname,$valuename,\%args,$skip_undef_values)
@arguments =
$ec2->member_key_value_parameters($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()
Returns the API version to be sent to the endpoint. Calls guess_version_from_endpoint() to
determine this.
$version = $ec2->guess_version_from_endpoint()
This method attempts to guess what version string to use when communicating with various
endpoints. When talking to endpoints that contain the string "Eucalyptus" uses the old EC2
API "2009-04-04". When talking to other endpoints, uses the latest EC2 version string.
$ts = $ec2->timestamp
@obj = $ec2->call($action,@param);
Make a call to Amazon using $action and the passed arguments, and return a list of
objects.
if $VM::EC2::ASYNC is set to true, then will return a AnyEvent::CondVar object instead of
a list of objects. You may retrieve the objects by calling recv() or setting a callback:
$VM::EC2::ASYNC = 1;
my $cv = $ec2->call('DescribeInstances');
my @obj = $cv->recv;
or
$VM::EC2::ASYNC = 1;
my $cv = $ec2->call('DescribeInstances');
$cv->cb(sub { my @objs = shift->recv;
do_something(@objs);
});
$url = $ec2->login_url(-credentials => $credentials, -issuer => $issuer_url, -destination =>
$console_url);
Returns an HTTP::Request object that points to the URL to login a user with STS
credentials
-credentials => $fed_token->credentials - Credentials from an $ec2->get_federation_token call
-token => $token - a SigninToken from $ec2->get_signin_token call
-issuer => $issuer_url
-destination => $console_url - URL of the AWS console. Defaults to https://console.aws.amazon.com/console/home
-auto_scaling_group_names List of auto scaling groups to describe
-names Alias of -auto_scaling_group_names
-credentials or -token are required for this method to work
Usage can be:
my $fed_token = $ec2->get_federation_token(...);
my $token = $ec2->get_signin_token(-credentials => $fed_token->credentials);
my $url = $ec2->login_url(-token => $token->{SigninToken}, -issuer => $issuer_url, -destination => $console_url);
Or:
my $fed_token = $ec2->get_federation_token(...);
my $url = $ec2->login_url(-credentials => $fed_token->credentials, -issuer => $issuer_url, -destination => $console_url);
$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').
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:
$ec2 = VM::EC2->new(-endpoint=>'https://ec2.amazonaws.com');
Subclassing VM::EC2 objects
To subclass VM::EC2 objects (or implement your own from scratch) you will need to override
the object dispatch mechanism. Fortunately this is very easy. After "use VM::EC2" call
VM::EC2::Dispatch->register() one or more times:
VM::EC2::Dispatch->register($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->register('call_name_1'=>\&subroutine1).
VM::EC2::Dispatch->register('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.