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, logical and rbd are supported. lvm2 is supported as an alias for logical, but this alias is deprecated and will be removed in a future release.
• capacity The capacity, in bytes, of the pool. (optional)
• 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. (only dir)
• owner The owner of the pool. (only dir)
• group The group of the pool. (only dir)
• source The name of the volume group (when type is logical) or RBD pool (when type is rbd).
• pvs A list of physical volumes the volume group consists of. (only when type is logical)
• hosts The list of the Ceph monitors IPs or hostnames. (only rbd)
• username The username used for RADOS authentification. (only rbd)
• passphrase The passphrase used for RADOS authentification. (only rbd)

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).
• routes Optional list of additionals routes defined as following:
  • address Address of the route, required.
  • prefix Prefix of the route, required.
  • gateway Gateway of the route, required.
  • metric Metric of the route (optional).
• ipv6 IPv6 address of the virtual bridge (optional).
• ipv6_prefix IPv6 prefix of the virtual bridge (optional).
• routesv6 Optional list of additionals IPv6 routes defined as following:
  • address IPv6 address of the route, required.
  • prefix IPv6 previx of the route, required.
  • gateway gateway of the route, required.
  • metric metric of the route (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.

libvirt_host_install_daemon: Whether to install and enable the libvirt daemon. Default is true.

libvirt_host_install_client: Whether to install and enable the libvirt client. Default is true.

libvirt_host_extra_daemon_packages: List of additional packages to install on libvirt daemon hosts.

libvirt_host_extra_client_packages: List of additional packages to install on libvirt client hosts.

libvirt_host_libvirtd_conf_enabled: Whether to configure libvirtd.conf. Default is true.

libvirt_host_libvirtd_conf: Configuration for libvirtd.conf. Dict mapping option names to values. Default is an empty dict.

libvirt_host_qemu_conf_enabled: Whether to configure qemu.conf. Default is true.

libvirt_host_qemu_conf: Configuration for qemu.conf. Dict mapping option names to values. Default is an empty dict.

libvirt_host_enable_sasl_support: Whether to enable SASL authentication support. Default is false.

libvirt_host_sasl_conf_enabled: Whether to configure SASL authentication (/etc/sasl2/libvirt.conf). Default is the same as libvirt_host_enable_sasl_support.

libvirt_host_sasl_conf: Configuration for SASL authentication (/etc/sasl2/libvirt.conf). String.

libvirt_host_sasl_mech_list: List of enabled libvirt SASL authentication mechanisms. Default is ["SCRAM-SHA-256"] when libvirt_host_tls_listen is true, otherwise ["DIGEST-MD5"].

libvirt_host_sasl_credentials: List of SASL authentication credentials to create. Each item is a dict containing username and password items. Default is a single item list containing libvirt_host_sasl_authname and libvirt_host_sasl_password.

libvirt_host_sasl_authname: Username for SASL authentication. Default is libvirt.

libvirt_host_sasl_password: Password for SASL authentication. Default is unset.

libvirt_host_sasl_auth_conf_enabled: Whether to configure SASL authentication credentials (/etc/libvirt/auth.conf). Default is the same as libvirt_host_enable_sasl_support.

libvirt_host_sasl_auth_conf: Configuration for SASL authentication credentials (/etc/libvirt/auth.conf). String.

libvirt_host_sasl_auth_conf_filename: Name of file to write SASL authentication credentials to. Default is "/etc/libvirt/auth.conf".

libvirt_host_sasl_auth_conf_owner: Owner of file to write SASL authentication credentials to. Default is "root".

libvirt_host_sasl_auth_conf_group: Group of file to write SASL authentication credentials to. Default is "root".

libvirt_host_sasl_auth_conf_mode: Mode of file to write SASL authentication credentials to. Default is "0600".

libvirt_host_tcp_listen: Whether to enable the systemd TCP socket unit. Default is false.

libvirt_host_tcp_listen_address: Systemd TCP socket ListenStream. See man systemd.socket for format. Default is unset.

libvirt_host_tls_listen: Whether to enable the systemd TLS socket unit. Default is false.

libvirt_host_tls_listen_address: Systemd TLS socket ListenStream. See man systemd.socket for format. Default is unset.

libvirt_host_tls_server_cert: TLS server certificate. Default is unset.

libvirt_host_tls_server_key: TLS server key. Default is unset.

libvirt_host_tls_client_cert: TLS client certificate. Default is unset.

libvirt_host_tls_client_key: TLS client key. Default is unset.

libvirt_host_tls_cacert: TLS CA certificate. Default is unset.

libvirt_host_configure_apparmor: Whether to configure AppArmor for directory storage pools.

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
        - name: lvm_pool
          type: logical
          source: vg1
          target: /dev/vg1
          pvs:
            - /dev/sda3
        - name: rbd-pool
          type: rbd
          source: rbd
          hosts:
            - 192.168.42.200
            - 192.168.42.204
            - 192.168.42.208
          username: admin
          passphrase: xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

      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)