Ubuntu 18: support Netplan configuration

[troyengel]

The new Ubuntu 18 release uses Netplan (a Canonical invention) to configure networking, as outlined here in these links:

• https://netplan.io/
• http://manpages.ubuntu.com/manpages/bionic/en/man5/netplan.5.html
• https://insights.ubuntu.com/2017/12/01/ubuntu-bionic-netplan

Bonding will require code updates to support writing the YAML, etc.

[terackspace]

Sorting out the desired end state, I ran into this shenanigan:

• https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1753431

It's unclear if being required to name the slaves with dummy data to define them is per design, or if it's a bug in implementation. It's enough to set dhcp4: false on the definition of the slave (which is already the default) to satisfy it's needs.

I also have found that an attempt to install ifenslave will trigger an install of ifupdown which is undesirable; unpacking the DEB file and using the script directly works fine, it seems to be a packaging thing. I'm going to engage Canonical about this item under our company login.

[terackspace]

Starting configuration - this device has a quad-port NIC, eno1 and eno2 are the bonding pair. The eno3 interface is a secondary network not associated with bonding, however provides a bit of context about the config itself on a real life server.

network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      addresses: [ 172.24.16.188/22 ]
      gateway4: 172.24.16.1
      nameservers:
          search: [ domain.com ]
          addresses:
              - "8.8.8.8"
              - "1.1.1.1"
    eno3:
      optional: true
      addresses: [ 10.132.99.73/27 ]
      routes:
        - to: 10.191.192.0/18
          via: 10.132.99.65
          on-link: true

The resulting bonded configuration which works with netplan generate and netplan apply on the fly (while logged in over SSH).

network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      dhcp4: false
      dhcp6: false
    eno2:
      dhcp4: false
      dhcp6: false
    eno3:
      optional: true
      addresses: [ 10.132.99.73/27 ]
      routes:
        - to: 10.191.192.0/18
          via: 10.132.99.65
          on-link: true
  bonds:
    bond0:
      addresses: [ 172.24.16.188/22 ]
      gateway4: 172.24.16.1
      nameservers:
          search: [ domain.com ]
          addresses:
            - "8.8.8.8"
            - "1.1.1.1"
      interfaces:
        - eno1
        - eno2
      parameters:
        mode: active-backup
        mii-monitor-interval: 100

The use of primary: <interface> is not required in the configuration of the bond.