ansible-network-role

WARNING: This role can be dangerous to use. If you lose network connectivity to your target host by incorrectly configuring your networking, you may be unable to recover without physical access to the machine. Try also the --check ansible option for a dry-run.

This role enables users to configure network on target machines. The role can be used to configure:

• Ethernet interfaces
• Bridge interfaces
• Bonded interfaces
• VLAN interfaces
• IP configuration

General

The role supports two providers: nm and initscripts. The provider can be configured per host via the provider variable. In absence of explicit configuration, it is autodetected based on the distribution. The nm provider is used by default on RHEL7 and initscripts on RHEL6. However, note that the provider is not tied to a certain distribution, given that the required API is available. For nm this means that at least version 1.2 of NetworkManager's API is available. For initscripts, it requires the legacy network service as commonly available on Fedora/RHEL.

For each host a list of networking profiles can be configure via the network variable.

• For NetworkManager, profiles correspond to connection profiles as handled by NetworkManager.

• For initscripts, profiles correspond to ifcfg files in /etc/sysconfig/network-scripts/ifcfg-*.

Note that the role primarily operates on networking profiles (connections) and not on devices. For example, in the role you would not configure the current IP address of an interface. Instead, you create a profile with a certain IP configuration and optionally activate the profile on a device. Which means, to apply the configuration to the actual networking interface.

Limitations

Configure over the Network

Ansible usually works via the network, for example via SSH. This role doesn't answer how to bootstrap networking configuration. One option may be ansible-pull. Another to initially auto-configure the host during installation (ISO based, kickstart, etc.), so that the host is connected to a management LAN or VLAN. It strongly depends on your environment.

• For initscripts provider, deploying a profile merely means to create the ifcfg files. Nothing happening automatically until the play issues ifup or ifdown via the up or down states -- unless of course, there are other components that watch the ifcfg files and react on changes.

• For NetworkManager, modifying a connection with autoconnect enabled may result in the activation of the new profile on a previously disconnected interface. Also, deleting a NetworkManager connection that is currently active will tear down the interface. Therefore, the order of the steps may matter and or careful handling of autoconnect property may be necessary. This should be improved in NetworkManager RFE rh#1401515.

• It seems difficult to change networking of the target host in a way that breaks the current SSH connection of ansible. If you want to do that, ansible-pull might be a solution. Alternatively, a combination of async/poll with changing the ansible_host midway of the play.
  TODO The current role doesn't yet support to easily split the play in a pre-configure step, and a second step to activate the new configuration.

In general, to successfully run the play, one must understand which configuration is active in the first place and then carefully configure a sequence of steps to change to the new configuration. Don't cut off the branch on which you are sitting. The actual solution depends strongly on your environment.

If something goes wrong

When something goes wrong while configuring the networking remotely, you might need to get phyisical access to the machine to recover.

• TODO NetworkManager supports a checkpoint/rollback feature. At the beginning of the play we could create a checkpoint and if we lose connectivity due to an error, NetworkManager would automatically rollback after timeout. The limitations is that this would only work with NetworkManager, and it's not clear that rollback will result in a working configuration either.

Invalid and Wrong Configuration

The role will reject invalid configurations, so it is a good idea to test the role with --check first. There is no protection against wrong (but valid) configuration. Double-check your configuration before applying it.

Compatibility

The role supports the same configuration scheme for both providers. That means, you can use the same playbook with NetworkManager and initscripts. Note however, that not every option is handled exactly the same by every provider. Do a test run first with --check.

It is also not supported to create a configuration for one provider, and expect another provider to handle them. For example, creating proviles with initscripts provider and later enabling NetworkManager is not guaranteed to work automatically. Possibly you have to adjust the configuration so that it can be used by another provider.

For example what will work is to configure a RHEL6 host with initscripts and upgrade to RHEL7 while continuing to use initscripts on RHEL7. What is not guaranteed to work it to upgrade to RHEL7, disable initscripts and expect NetworkManager to take over the configuration automatically.

Depending on NetworkManager's configuration, connections may be stored as ifcfg files as well, but again it is not guaranteed that plain initscripts can handle these ifcfg files after disabling the NetworkManager service.

Variables

The role is configured via the network dictionary variable per host. The connection profiles are configured as network.connections, which is a list of dictionaries that have a name.

name

The name identifies the connection profile. It is not the name of the networking interface for which the profile applies, though it makes sense to restrict the profile to an interface and give them the same name. Note also that you can have multiple profiles for the same device, but of course only one profile can be active on the device at each time. Note that for NetworkManager, a connection can only be active at one device at a time.

• For NetworkManager, the name translates to connection.id. Altough NetworkManager supports multiple connections with the same connection.id, this role cannot handle a duplicate name. Specifying a name multiple times refers to the same connection profile.

• For initscripts, the name determines the ifcfg file name /etc/sysconfig/network-scripts/-ifcfg-$NAME. Note that here too the name doesn't specify the DEVICE but a filename. As a consequence '/' is not a valid character for the name.

state

Example

network:
  connections:
    - name: "eth0"
      state: "absent"

Above example ensures the absence of a connection profile. If a profile with name eth0 exists, it will be deleted.

• For NetworkManager this deletes all connection profiles with the matching connection.id. Deleting a profile usually does not change the current networking configuration, unless the profile was currently activated on a device. In that case deleting the currently active connection profile disconnects the device. That makes the device eligible to autoconnect another connection (see also rh#1401515).

• For initscripts it results in the deletion of the ifcfg file. Usually that has no side-effect, unless some component is watching the sysconfig directory.

We already saw that state absent before. There are more states:

• absent
• present
• up
• down

If the state variable is omitted, the default is up -- unless a type is specified, in which case the default is present.

Example

network:
  connections:
    - name: "eth0"
      #state: present        # default, as a type is present
      type: "ethernet"
      autoconnect: yes
      mac: "d6:06:b9:56:12:5d"
      ip:
        dhcp4: yes

Above example creates a new connection profile or ensures that it is present with the given configuration. It has implicitly state present, due to the presence of type. On the other hand, the present state requires at least a type variable.

Valid values for type are:

• ethernet
• bridge
• bond
• team
• vlan

state present does not directly result in a change in the network configuration. That is, the profile is only created or modified, not activated.

• For NetworkManager, note the new connection profile is created with autoconnect turned on by default. Thus, NetworkManager may very well decide right away to activate the new profile on a currently disconnected device. (rh#1401515).

autoconnect

By default, profiles are created with autoconnect enabled.

• For NetworkManager, this translates to the connection.autoconnect property.

• For initscripts, this corresponds to the ONBOOT property.

mac

The mac address is optional and restricts the profile to be usable only on devices with the given MAC address. mac only makes sense for type ethernet to match a non-virtual device with the profile.

• For NetworkManager mac is the permanent MAC address ethernet.mac-address.

• For initscripts, this means the currently configurd MAC address of the device (HWADDR).

interface_name

For type ethernet, this option restricts the profile to the given interface by name. This argument is optional and by default a profile is not restricted to any interface by name. Note that with persistent interface naming, the interface is predictable based on the hardware configuration. Otherwise, the mac address might be an option.

For virtual interface types like bridges, this argument is the name of the created interface. In case of a missing interface_name, the profile name name is used.

Note the destinction between the profile name name and the device name interface_name, which may or may not be the same.

state: up

Example

network:
  connections:
    - name: "eth0"
      #state: up        # implicit default, as there is no type specified
      wait: 0

The above example defaults to state=up and requires an existing profile to activate. Note that if neither type nor state is specifed, up is implied. Thus in above example the state is redundant.

• For NetworkManager this results in nmcli connection id {{name}} up.

• For initscripts it is the same as ifup {{name}}.

up also supports an optional integer argument wait. wait=0 will only initiate the activation but not wait until the device is fully connected. Connection will complete in the background, for example after a DHCP lease was received. wait: <SECONDS> is a timeout for how long we give the device to activate. The default is wait=-1 which uses a suitable timeout. Note that this argument only makes sense for NetworkManager. TODO wait different from zero is not yet implemented.

Note that up always re-activates the profile and possibly changes the networking configuration, even if the profile was already active before. As such, it always changes the system.

state: down

Example

network:
  connections:
    - name: eth0
      state: down
      wait: 0

Another state is down.

• For NetworkManager it is like calling nmcli connection id {{name}} down.

• For initscripts this means to call ifdown {{name}}.

This is the opposite of the up state. It also will always issue the command to deactivate the profile, even it if seemingly is currently not active. As such, down always changes the system.

For NetworkManager, a wait argument is supported like for up state.

Refer to the same connection multiple times

Example

network:
  connections:
    - name: "Wired0"
      type: "ethernet"
      interface_name: "eth0"
      ip:
        dhcp4: yes

    - name: "Wired0"

As said, the name identifies a unique profile. However, you can refer to the same profile multiple times. Thus above example makes perfectly sense to create a profile and activate it within the same play.

ip

The IP configuration supports the following options:

network:
  connections:
    - name: "eth0"
      type: "ethernet"
      ip:
        route_metric4: 100
        dhcp4: no
        #dhcp4_send_hostname: no
        gateway4: 192.168.5.1

        route_metric6: -1
        auto6: no
        gateway6: fc00::1

        address:
          - 192.168.5.3/24
          - 10.0.10.3/16
          - fc00::80/7

Manual addressing can be specified via a list of addresses and prefixes address. Also, manual addressing can be combined with either dhcp4 and auto6 for DHCPv4 and SLAAC. The dhcp4 and auto6 keys can be omitted and the default depends on the presence of manual addresses.

If dhcp4 is enabled, it can be configured whether the DHCPv4 request includes the hostname via dhcp4_send_hostname. Note that dhcp4_send_hostname is only supported by the nm provider and translates to ipv4.dhcp-send-hostname property.

• For NetworkManager, route_metric4 and route_metric6 corresponds to the ipv4.route-metric and ipv6.route-metric properties, respectively. If specified, it determines the route metric for DHCP assigned routes and the default route, and thus the priority for multiple interfaces.

Slaves to bridge/bond/team devices cannot specify ip settings.

Virtual types and Slaves

Device types like bridge, bond, team work similar:

network:
  connections:
    - name: "br0"
      type: bridge
      #interface_name: br0    # defaults to the connection name

Note that team is not supported on RHEL6 kernels.

For slaves of these virtual types, the special properites slave_type and master must be set. Also note that slaves cannot have ip settings.

network:
  connections:
    - name: br0
      type: bridge
      ip:
        dhcp4: no
        auto6: no

    - name: br0-bond0
      type: bond
      interface_name: bond0
      master: br0
      slave_type: bridge

    - name: br0-bond0-eth1
      type: ethernet
      interface_name: eth1
      master: br0-bond0
      slave_type: bond

Note that the master refers to the name of a profile in the ansible playbook. That is, it is neither an interface-name, nor a connection-id of NetworkManager.

• For NetworkManager, master will be converted to the connection.uuid of the corresponding profile.

• For initscripts, the master is looked up as the DEVICE from the corresponding ifcfg file.

As master refers to other profiles of the same or another play, the order of the connections list matters. Also, --check ignores the value of the master and assumes it will be present during a real run. That means, in presence of an invalid master, --check may signal success but the actual play run fails.

type: vlan

VLANs work too:

network:
  connections:
    - name: eth1-profile
      autoconnet: no
      type: ethernet
      interface_name: eth1
      ip:
        dhcp4: no
        auto6: no

    - name: eth1.6
      autoconnect: no
      type: vlan
      parent: eth1-profile
      vlan_id: 6
      ip:
        address:
          - 192.168.10.5/24
        auto6: no

Like for master, the parent references the connection profile in the ansible role.

provider

Whether to use nm or initscripts is detected based on the distribution. It can be however be explicitly set via network.provider or network_provider variables.

Example

network:
  provider: nm
  connections:
    - name: "eth0"
      #...