Libvirt Host

This role configures a host as a Libvirt/KVM hypervisor. It can also configure storage pools and networks on the host.

Requirements

The host should have Virtualization Technology (VT) enabled.

Role Variables

libvirt_host_pools is a list of pools to define and start. Each item should be a dict containing the following items:

name The name of the pool.
type The type of the pool, currently only dir is supported.
capacity The capacity, in bytes, of the pool.
path The absolute path to the pool's backing directory.
mode The access mode of the pool. N.B.: This should be specified as an integer without a leading zero; for example: mode: 755.
owner The owner of the pool.
group The group of the pool.

libvirt_host_networks is a list of networks to define and start. Each item should be a dict containing the following items:

name The name of the network.
mode The forwarding mode of the network, bridge, route and nat are supported.
bridge The name of the bridge interface for this network.
ip IP address of the virtual bridge, mandatory for route and nat mode.
netmask Netmask of the virtual bridge, mandatory for route and nat mode.
domain DNS domain name for route and nat mode, default to the network name (optional).
dhcp_start First IP of the DHCP range in route or nat mode (optional).
dhcp_end Last IP of the DHCP range in route or nat mode (optional).

libvirt_host_require_vt is whether to require that Intel Virtualisation Technology (VT) is enabled in order to run this role. While this provides better VM performance, it may not be available in certain environments. The default value is true.

libvirt_host_qemu_emulators: List of architectures for which to install QEMU system emulators, e.g. x86. The default value is ['x86'] if

libvirt_host_require_vt is false, otherwise the default value is an empty list.

libvirt_host_enable_efi_support: Whether to enable EFI support. This defaults to false as extra packages need to be installed.

libvirt_host_var_prefix: This determines The directory under /var/run that libvirt uses to store state, e.g unix domain sockets, as well as the default name of the PID file. Override this if you have a conflict with the default socket e.g it could be in use by the nova_libvirt container. Defaults to "".

libvirt_host_socket_dir: Where the libvirtd socket is created. Defaults to /var/run/{{ libvirt_host_var_prefix }} if libvirt_host_var_prefix is set, otherwise "".

libvirt_host_pid_path: Path to PID file which prevents multiple instances of the daemon from spawning. Defaults to /var/run/{{ libvirt_host_var_prefix }}.pid if libvirt_host_var_prefix is set, otherwise "".

libvirt_host_libvirtd_args: Command line arguments passed to libvirtd by the init system when libvirtd is started - quotes will be added

libvirt_host_uri: The libvirt connnection URI. Defaults to qemu+unix:///system?socket={{ libvirt_host_socket_dir }}/libvirt-sock if libvirt_host_var_prefix is set, otherwise "". If set to a falsey value, an explicit connection URI will not be set when calling virsh or any of the virt_ ansible modules.

libvirt_host_python3: Whether the python3 version of the libvirt python bindings should be installed. If false, the python 2 bindings will be installed.

Dependencies

None

Example Playbook

---
- name: Ensure that Libvirt is configured
  hosts: all
  roles:
    - role: stackhpc.libvirt-host
      libvirt_host_pools:
        - name: my-pool
          type: dir
          capacity: 1024
          path: /path/to/pool
          mode: 755
          owner: my-user
          group: my-group
      libvirt_host_networks:
        - name: br-example
          mode: bridge
          bridge: br-example
        - name: brnat-example
          mode: nat
          bridge: brnat-example
          domain: example.local
          ip: 192.168.133.254
          netmask: 255.255.255.0
          dhcp_start: 192.168.133.100
          dhcp_end: 192.168.133.200

Author Information

Mark Goddard (mark@stackhpc.com)