Libvirt VM

This role configures and creates (or destroys) VMs on a KVM hypervisor.

Requirements

The host should have Virtualization Technology (VT) enabled and should be preconfigured with libvirt/KVM.

Role Variables

• libvirt_vm_default_console_log_dir: The default directory in which to store VM console logs, if a VM-specific log file path is not given. Default is "/var/log/libvirt/qemu/".

• libvirt_vm_image_cache_path: The directory in which to cache downloaded images. Default is "/tmp/".

• libvirt_vm_engine: virtualisation engine. If not set, the role will attempt to auto-detect the optimal engine to use.

• libvirt_vm_emulator: path to emulator binary. If not set, the role will attempt to auto-detect the correct emulator to use.

• libvirt_vm_arch: CPU architecture, default is x86_64.

• libvirt_vm_uri: Override the libvirt connection URI. See the libvirt docs docs for more details.

• libvirt_vm_virsh_default_env: Variables contained within this dictionary are added to the environment used when executing virsh commands.

• libvirt_vms: list of VMs to be created/destroyed. Each one may have the following attributes:

  • state: set to present to create or absent to destroy the VM. Defaults to present.

  • name: the name to assign to the VM.

  • memory_mb: the memory to assign to the VM, in megabytes.

  • vcpus: the number of VCPU cores to assign to the VM.

  • machine: Virtual machine type. Default is None if libvirt_vm_engine is kvm, otherwise pc-1.0.

  • cpu_mode: Virtual machine CPU mode. Default is host-passthrough if libvirt_vm_engine is kvm, otherwise host-model.

  • volumes: a list of volumes to attach to the VM. Each volume is defined with the following dict:

    • pool: Name or UUID of the storage pool from which the volume should be allocated.
    • name: Name to associate with the volume being created.
    • capacity: volume capacity (can be suffixed with M,G,T or MB,GB,TB, etc)
    • device: disk
    • format: options include raw, qcow2, vmdk. See man virsh for the full range. Default is qcow2
    • image: (optional) a URL to an image with which the volume is initalised (full copy).
    • backing_image: (optional) name of the backing volume which is assumed to already be the same pool (copy-on-write).
    • image and backing_image are mutually exclusive options.

  • interfaces: a list of network interfaces to attach to the VM. Each network interface is defined with the following dict:

    • type: The type of the interface. Possible values:

      • network: Attaches the interface to a named Libvirt virtual network. This is the default value.
      • direct: Directly attaches the interface to one of the host's physical interfaces, using the macvtap driver.

    • network: Name of the network to which an interface should be attached. Must be specified if and only if the interface type is network.

    • source: A dict defining the host interface to which this VM interface should be attached. Must be specified if and only if the interface type is direct. Includes the following attributes:

      • dev: The name of the host interface to which this VM interface should be attached.
      • mode: options include vepa, bridge, private and passthrough. See man virsh for more details. Default is vepa.

  • console_log_enabled: if true, log console output to a file at the path specified by console_log_path, instead of to a PTY. If false, direct terminal output to a PTY at serial port 0. Default is false.

  • console_log_path: Path to console log file. Default is {{ libvirt_vm_default_console_log_dir }}/{{ name }}-console.log.

  • start: Whether to immediately start the VM after defining it. Default is true.

  • autostart: Whether to start the VM when the host starts up. Default is true.

  • xml_template: Optionally supply a modified XML template. Base customisation off the default vm.xml.j2 template so as to include the expected jinja expressions the role uses.

N.B. the following variables are deprecated: libvirt_vm_state, libvirt_vm_name, libvirt_vm_memory_mb, libvirt_vm_vcpus, libvirt_vm_engine, libvirt_vm_machine, libvirt_vm_cpu_mode, libvirt_vm_volumes, libvirt_vm_interfaces and libvirt_vm_console_log_path. If the variable libvirt_vms is left unset, its default value will be a singleton list containing a VM specification using these deprecated variables.

Dependencies

None

Example Playbook

---
- name: Create VMs
  hosts: hypervisor
  roles:
    - role: stackhpc.libvirt-vm
      libvirt_vms:
        - state: present
          name: 'vm1'
          memory_mb: 512
          vcpus: 2
          volumes:
            - name: 'data1'
              device: 'disk'
              format: 'qcow2'
              capacity: '400GB'
              pool: 'my-pool'
          interfaces:
            - network: 'br-datacentre'

        - state: present
          name: 'vm2'
          memory_mb: 1024
          vcpus: 1
          volumes:
            - name: 'data2'
              device: 'disk'
              format: 'qcow2'
              capacity: '200GB'
              pool: 'my-pool'
          interfaces:
            - network: 'br-datacentre'

Author Information

• Mark Goddard ([email protected])