Support for setting RoutesToDNS=true/false

[Richard Cunningham]

As per https://askubuntu.com/questions/1410196/dhcp-provided-dns-server-with-wrong-route-in-ubuntu-server-22-04 there seems to be no way to set RoutesToDNS via netplan config. This is causing issues bringing up machines in Openstack where DHCP supplies DNS addresses but the OS installs a route towards it's own interfaces and breaks DNS routing completely.

The solution described in the article above is a valid workaround but quite inconvenient and in an environment where we also rename the interfaces via udev rules dynamically the boot timing starts to get complicated.

It would be much more simple if we could just stop these routes being installed via netplan configuration.

[Lukas Märdian (slyon)]

This sounds like a fair feature request. Pull request are welcome against our upstream repository: https://github.com/canonical/netplan