Provided by: uvtool-libvirt_0~git178-0ubuntu1_all bug


       uvt-kvm - Ubuntu virtualisation front-end for libvirt and KVM


       uvt-kvm list

       uvt-kvm create [options] name [filter ...]

       uvt-kvm wait [options] name

       uvt-kvm ip name

       uvt-kvm ssh [options] [user@]name [command ...]

       uvt-kvm destroy name


       uvtool  provides  a  unified  and integrated VM front-end to Ubuntu cloud image downloads,
       libvirt, and cloud-init.

       uvt-kvm uses the volume storage pool maintained by uvt-simplestreams-libvirt(1) as a basis
       to provide quick start and management of Ubuntu VMs by wrapping libvirt and cloud-init.

       uvt-kvm is not intended to wrap all possible use cases. Where possible, it provides access
       to some more  advanced  cases  using  options  to  override  entire  sections  of  default
       operation,  such  as  the  ability to directly override the backing volume image used, the
       libvirt domain definition, cloud-init  metadata  and  userdata,  and  directly  provide  a
       network-config  file.   For yet more complex cases, it is expected that the user will call
       libvirt directly (for example by using virsh(1)), and use uvt-kvm  for  only  the  simpler
       operations  required on affected VMs. See ADVANCED OVERRIDE OPTIONS and ADVANCED USAGE for


       uvt-kvm's interface is designed around subcommands. The subcommand  to  be  used  must  be
       specified  as  the first positional argument. Each subcommand has its own set of available

       Where a subcommand requires a VM to be specified, the VM name must be provided as a second
       positional  argument. When using uvt-kvm create to create VMs, the VM name is specified by
       the user at this time. Where  users  have  manipulated  libvirt  directly,  VM  names  are
       expected to match libvirt domain names.

       uvt-kvm list

       Print  a list of existing VMs to stdout. This list currently includes libvirt domains that
       are defined but were not created by uvt-kvm, but in future this is expected to  change  to
       VMs created by uvt-kvm only.

       uvt-kvm create [options] name [filter ...]

       Create a new VM based on a backing volume specified by the provided simplestreams filters.
       This VM will be called name, and the same name must be used when referring to the VM  from
       the other subcommands.

       Each filter operates on the images downloaded and managed by uvt-simplestreams-libvirt(1),
       and when combined together must uniquely specify a single  image.  See  uvt-simplestreams-
       libvirt(1) for details on image selection.

       Since backing volume images are downloaded and maintained by uvt-simplestreams-libvirt(1),
       it is necessary to first run uvt-simplestreams-libvirt(1) to download images  before  this
       subcommand will succeed. See EXAMPLES, below.

       If  no  filters  are  specified,  a  filter  of  release=release is assumed, where release
       corresponds to the current LTS release as returned by distro-info(1).

       Alternatively, see --backing-image-file under ADVANCED OVERRIDE OPTIONS below to supply  a
       backing image directly yourself.

       This subcommand supports an extensive set of options to modify the definition and behavior
       ADVANCED OVERRIDE OPTIONS below. Other general behavioural options:

       --no-start     Do  not  start  the  VM  after  creation.  This  is  useful to make further
                      customisations to the VM before using it. To start the VM  when  done,  use
                      virsh start name.

       uvt-kvm wait [options] name

       Wait for a VM to become ready. This includes: waiting for the VM to request an IP address,
       waiting for ssh to become available on this IP, and an ssh(1) operation  into  the  VM  to
       wait for cloud-init to finish and the system to enter runlevel 2.

       By  using  the  wait command, scripts can create, operate on and destroy VMs synchronously
       and reliably.

       --timeout timeout
                    Give up waiting after timeout seconds. Default: 120 seconds.

       --interval interval
                    For wait operations that must poll, poll every interval seconds.  Default:  8

       --remote-wait-script remote_wait_script
                    Run  remote_wait_script  through  sh(1) on the guest system, which must block
                    and  exit  with  a  zero  status  when  the   system   is   ready.   Default:
                    /usr/share/uvtool/,  which  assumes that upstart and cloud-init
                    are being used on the guest, waits for upstart to enter runlevel 2  and  then
                    waits for cloud-init to signal that it has finished booting the system.

                    When  remote_wait_script  is  run  on  the guest system, its environment will
                    define  the  variables  UVTOOL_WAIT_INTERVAL  and  UVTOOL_WAIT_TIMEOUT  which
                    contain the poll interval and wait timeout as specified by the --interval and
                    --timeout options, respectively.

       --remote-wait-user user
                    Run the remote wait script as user user.  It must be possible to ssh(1)  into
                    the guest system as this user for the remote wait mechanism to work.

       --insecure   Permit potentially insecure operations. See COMMON OPTIONS, below.

       --ssh-private-key-file ssh_private_key_file
                    Use ssh_private_key_file to authenticate to the guest machine when performing
                    the ssh(1) operation

                    Skip the ssh(1) operation. This will cause the command to exit  with  success
                    as  soon  as  the  ssh port is available, but without logging to the guest to
                    wait until it is ready internally.

       uvt-kvm ip name

       Guess the IP address of a VM and print it to stdout. Currently,  this  assumes  a  default
       (Ubuntu) installation of libvirt and dnsmasq on the host, and default networking behaviour
       on the VM. IP address guessing is currently implemented via libvirt-python.

       This subcommand assumes that the VM has successfully acquired an IP address, and will fail
       otherwise.  Callers can use uvt-kvm wait after creating or rebooting a VM to wait for this
       to become the case.

       In future, this subcommand may incorporate multiple IP address detection mechanisms.

       uvt-kvm ssh [options] [user@]name [command ...]

       Run ssh(1) against the VM. This is a limited wrapper around ssh(1) and the ip  subcommand,
       designed for ease-of-use in the common case. For full functionality, use the ip subcommand
       to obtain the VM's IP address, and then call ssh(1) directly instead.

       --insecure  Permit potentially insecure operations. See COMMON OPTIONS, below.

       --login-name user
       -l user

                   Specify the username to pass to ssh(1).  This is the  recommended  method  for
                   use  in scripts. This option overrides the username provided by the @ notation
                   in the first positional argument, and thus allows the VM name to include an  @
                   symbol. Default: ubuntu, to match the default on Ubuntu cloud images.

       uvt-kvm destroy name

       Stop  and  completely  destroy  an  existing  VM.  This  stops the libvirt domain if it is
       running, undefines it, and deletes  all  volumes  that  had  been  part  of  the  domain's
       definition. It does not, however, delete any backing volumes, thus keeping intact pristine
       Ubuntu cloud images as maintained by uvt-simplestreams-libvirt(8).


              Valid for: uvt-kvm wait, uvt-kvm ssh.

              Permit connections which may not be secure. For ssh(1) connections, this skips host
              key  validation.  This  is  no longer be required in the default case, since uvtool
              creates the guest's host keys, supplies them to the guest via cloud-init, and  thus
              knows  and  sets  the  expected  host  public key automatically. In the common non-
              default case, --insecure may be required but still should not be  a  problem  since
              the  guest  system  is  located  on  the  same  system and this network path can be
              trusted. However, uvt-kvm will refuse to make a  connection  (for  uvt-kvm ssh)  or
              skip steps (for uvt-kvm wait) without this option, in order to make absolutely sure
              that the user cannot compromise his path to the guest system without being aware of
              this caveat.

              Valid for: uvt-kvm create only.

              Turn  on  a  set  of options deemed most useful for developers but not suitable for
              turning on by default. Currently this is the same  as  specifying  --unsafe-caching
              and --log-console-output but this may change between releases.

              Scripts  should  never  use  this  option. To protect against future changes to the
              definition of this option, they should instead use the expansion defined above.


       Valid for: uvt-kvm create only.

       These options modify the definition of the guest VM, and its connection to the host.

       uvt-kvm create takes the default or user-supplied libvirt domain XML  template  definition
       and  modifies  it  according  to  the following parameters. Each of these parameters has a
       sensible default which may change between releases.

       --memory size
              Amount of system RAM in megabytes. Default: 512 (MiB).

       --disk size
              Size of the OS disk in gigabytes. Default: 8 (GiB).

       --ephemeral-disk size
              Add an ephemeral disk of Size gigabytes.

              Do not flush guest syncs to the host on the OS disk. This  can  improve  guest  I/O
              performance  at  the  cost  of  losing  data on host power failure.  This option is
              useful for ephemeral guest machines that do not need to be persistent beyond a host
              power cycle.

       --cpu cores
              Number of CPU cores. Default: 1.

       --bridge bridge
              Replace  the  first  defined  NIC  with one that connects to the given host bridge.
              Default: unaltered from the libvirt domain template.

       --mac mac
              Use this MAC address for the first defined NIC. Can be  used  in  conjunction  with
              --bridge. Default unspecified.

              Log  output  to a disk file on the host instead of to a pty. With libvirt's default
              configuration on Ubuntu, this log can be found in /var/log/libvirt/qemu/<name>.log.
              This  options  enables  retrospective  examination of VM console output, but breaks
              virsh console for interactive use.  On s390x this option is currently not supported
              due to incompatibilties with the sclp console used.

              Instead  of  the  default  CPU  model  -  which  is  host-model this will use host-
              passthrough which will try to make all of the host's CPU  features  (not  migration
              safe) available in the guest.  This option is deprecated and will later be removed.
              Please use --model instead.

              Set the CPU model that shall be used.  The default generally is host-model,  except
              on  arm64  where host-model won't work - there the default is host-passthrough.  If
              set to host-model or host-passthrough this will set the CPU mode.  If  set  to  any
              other  string  it will be handled as a named CPU passed to libvirt.  Allowed values
              are all CPUs listed on your host as usable=yes in  `virsh  domcapabilities`.   This
              option  has  no effect if the target is emulated, in this case the safe defaults of
              libvirt will be used.

       --machine-type type
              Set the machine type to the specified string before instantiating the  guest.   See
              kvm  -M  ?  for  a list of types supported by your current system.  If not set this
              section of the template is not altered before the guest is defined.   If  set  this
              modifies   the   internal   temporary   libvirt  domain  template  at  the  element
              domain->os->type and sets the attribute machine to the given value before  defining
              the  guest.  This  implies that libvirt will add the type-dependent default devices
              when defining the guest.

              If --machine-type is not specified, the current host is an x86_64  system  and  the
              requested  guest  is arch=amd64 then the machine type will by default be set to the
              latest available q35 based type to  overcome  the  ancient  compatibility  oriented
              defaults of libvirt on x86.


       Valid for: uvt-kvm create only.

       These options modify operation within the guest VM itself.

       Unless  --user-data  is  used  to  override  this  behaviour, uvt-kvm generates cloud-init
       userdata with some sensible defaults when a VM is created. These defaults can  be  altered
       using the following options:

       --password password

              Permit  login  to the VM to the default user ubuntu and password password.  This is
              useful for debugging purposes, since it  also  enables  a  VT  login.   Using  this
              command  line  option leaks the password used to other users on the same system, so
              should never be used in production for security reasons.

              Default: no password login.

       --run-script-once script_file
              Run script_file as root on the VM the first time it is  booted,  but  never  again.
              This option can be used multiple times to run multiple scripts. If the script exits
              with a non-zero status, it will be left on the VM in /tmp for debugging purposes.

              script_file will be copied  to  the  guest,  marked  as  executable,  and  executed
              directly,  so  it must be an appropriate binary, start with a shebang, or otherwise
              be directly executable by the guest kernel.

              Default: no scripts.

       --ssh-public-key-file ssh_public_key_file

              Permit login to the VM to the default user ubuntu and the  ssh  keys  specified  in

              Default:   use   the   output   of   ssh-add -L   if   available;   otherwise   use
              ~/.ssh/  If no source is found at all, then a warning will be printed to
              stderr, and VM creation will continue with no arrangement for access to the guest.

       --packages package_list

              Install  the comma-separated packages specified in package_list on first boot. This
              option can be used multiple times; each additional option adds to the final package

              Default: no packages.


       Valid for: uvt-kvm create only.

       --template template_file
              The base libvirt domain definition XML template to use when constructing a new VM's
              definition. This is dynamically altered before domain creation; see LIBVIRT  DOMAIN

              Default: /usr/share/uvtool/libvirt/template.xml.

       --guest-arch architecture
              Specify  the  architecture of the guest template file that will be selected.  If an
              explicit  --template  is  given  then  --guest-arch  has  no  effect.   If  neither
              --template  nor  --guest-arch  are  set  the  host's  architecture  will be used to
              determine the default xml template.

              If you set an architecture that requires emulation on the current  host  the  guest
              will be set up for that. See EMULATION OF FOREIGN ARCHITECTURES for more details on
              using an architecture that is different to the current system.

              Default: Current Host architecture

       --user-data user_data_file
              Override cloud-init userdata, instead using the file supplied. This  overrides  all
              options in the section CLOUD-INIT CONFIGURATION OPTIONS.

              Default: as described in CLOUD-INIT CONFIGURATION OPTIONS.

       --meta-data meta_data_file
              Override  default  cloud-init metadata, instead using the file supplied.  This does
              not override any other options, since cloud-init metadata is not otherwise tunable.

              Default: minimal file with automatically generated instance-id.

       --network-config network_config_file
              Provide cloud-init network-config using the file supplied.

              Default: no network-config file.

       --backing-image-file image_file
              Specify the name of a local file that will be used to  create  the  VM  instead  of
              relying  on the volume storage pool. It must point to a qcow2 formatted file.  This
              option overrides any simplestreams filters provided.


       uvt-kvm is carefully constructed to avoid impeding the ability of the user to directly use
       virsh(1)  or  other  libvirt  tooling at any time, and provides override options to supply
       backing image volumes and cloud-init userdata and metadata where possible. VMs created  by
       uvt-kvm  are not "special" in libvirt. What uvt-kvm does with VMs is well-defined, so that
       advanced users can manipulate a VM using libvirt directly without necessarily  losing  the
       ability for uvt-kvm to continue to manipulate that VM for common use cases.

       For  simplicity,  uvt-kvm  uses create to mean the definition, allocation and running of a
       VM, and destroy to mean the stopping and removing of all persistent state associated  with
       a  VM,  including  VM-specific disk image files and the VM definition itself. This matches
       the commonly expected lifecycle of VMs created with uvt-kvm.

       This works well for the common use case, but if  VMs  created  with  uvt-kvm  need  to  be
       manipulated with virsh(1) or libvirt directly, then it becomes necessary to understand how
       this matches up to the more complex libvirt terminology.

       In libvirt, a VM is called a domain.  A domain is first defined,  and  then  independently
       started.  In  libvirt  terminology,  destroy  means a VM stop; after a destroy, the domain
       still exists and can be  restarted.   undefine  finally  removes  the  domain  definition.
       Resources  associated  with  a  VM  (such as disk image files, which in libvirt are called
       volumes) must be created and destroyed separately.

       When uvt-kvm creates a VM, libvirt volumes are defined and populated, a libvirt domain  is
       defined,  marked  as  autostarted, and the domain started. When uvt-kvm destroys a VM, the
       corresponding libvirt domain is stopped, domain-specific volumes deleted and  the  libvirt
       domain itself is undefined.

       emulation  of  foreign  architectures  can be done with uvt-kvm. Currently armhf being the
       only supported target architecture. Please  be  aware  that  defining  filters  to  use  a
       different  architecture  image will not be enough. To let uvtool know that you want to run
       as a specific architecture you need to set --guest-arch If that is set to armhf (just like
       your simplestreams filters for the image would be) then uvt-kvm will use qemu-system-arm

       Since  in  these modes bootloaders often struggle uvt-kvm will provide externel kernel and
       initrd to boot the guest. To be able to extract those from the guest image it  needs  root
       permission when syncing the non native architecture image.


       # Update uvtool's libvirt volume storage pool with the
       # latest Precise image
       uvt-simplestreams-libvirt sync release=precise arch=amd64

       # Create an ssh key for the local user (if you don't have
       # one already)
       # (...)

       # Create an amd64 VM running Precise
       uvt-kvm create myvm release=precise arch=amd64

       # Wait for the VM to become ready
       uvt-kvm wait --insecure myvm

       # Shell into the VM to do some testing there
       uvt-kvm ssh --insecure myvm
       # (...)

       # Destroy the VM
       uvt-kvm destroy myvm


   Common Errors
       Failed to connect socket to '/var/run/libvirt/libvirt-sock': Permission denied

       Do  you  have  permission to connect to libvirt? On Ubuntu, you must belong to the libvirt
       group (this group was named libvirtd on 16.04 and earlier). Users with sudo(8) access  are
       added  to  this  group  by  default, but users only get group membership on the next login
       after the libvirt-bin package has been installed. To  temporarily  add  yourself  to  this
       group  in  advance of your next login, try newgrp libvirt (or newgrp libvirtd if on Ubuntu
       16.04 or earlier).

       no supported architecture for os type 'hvm'

       libvirt did not find KVM support on your system.  Try  sudo kvm-ok  for  diagnostics,  and
       service libvirt-bin restart to pick up any changes before retrying.

   Interactive console access
       If  you  cannot access the VM from the host system, try using --password to set a password
       for the default ubuntu user inside the VM, and then logging in to the VM over the  console
       in order to examine it from the inside.

       To   access   the  console  interactively,  use  virsh console name.  However,  note  that
       interactive access is disabled if  you  are  using  --log-console-output  or  -d,  so  for
       interactive access you will have to drop these options if you are using them.

       If  you  are using --user-data, then --password will be overridden by it and you will need
       to modify your cloud-init userdata manually to achieve the same effect.


       uvt-simplestreams-libvirt(1), distro-info(1), dnsmasq(8), virsh(1).