'gateway4' is cumbersome

[Mark Shuttleworth]

Most of us still live in an IPv4 world, and being explicit about that seems cumbersome. Could the syntax for netplan accommodate these:

  gateway: v4-addr
  gateway: v6-addr
  gateway: [ v4-addr, v6-addr ]

In other words, either give the one, or the other, or a list of both?

[Mathieu Trudel-Lapierre (cyphermox)]

The list looks to me like a support case waiting to happen. It might have people think they can add more ipv4 addresses as "gateway", and then they might not get the behavior they expect (should it be multiple gateways at the same metric? only the last applies? etc.)

I wonder if it would work well to deprecate that syntax and instead push for people to write routes: ; provided we make it easier and clearer to write a default route.

[Mark Shuttleworth (sabdfl)]

I don't think the risk is very high, since 'netplan generate' would surely provide helpful feedback ;)

[Lukas Märdian (slyon)]

After some more discussion with the netplan team, we decided to deprecate the 'gateway4/6' fields in favor of using 'default' routes. The 'to: default' stanza was introduced to the routing configuration, which is a shortcut that works in the same way for IPv4 and IPv6.

The documentation was updated accordingly, and if somebody uses the (now deprecated) gateway4/6 fields it will still work, but print a warning.

https://github.com/canonical/netplan/pull/216

This is available as of netplan.io 0.103