IPAM added routes incompatible with vrf plugin

[chdxD1]

With #1151, more specifically https://github.com/mlguerrero12/plugins/blob/76020abb755d3e21776b752a80af1c65fa9e622c/plugins/meta/vrf/vrf.go#L122-L128, routes that are added without a src are filtered out when moving the interface to the VRF.

Creating routes without source is the default for the ipam_linux.go implementation: https://github.com/containernetworking/plugins/blob/main/pkg/ipam/ipam_linux.go#L133-L138

This leads to routes being dropped by the vrf CNI that were added previously by e.g. the macvlan CNI.

Maybe @mlguerrero12, can you elaborate why the specific route filter was needed? ("There were some routes that don't need to be added.")

[chdxD1]

Looking at the comment ("filter out connected IPV6 routes") it would make more sense to filter for route.Family == netlink.FAMILY_V4 || route.Gw != nil?

Probably the goal is to filter these routes here: fe80::/64 dev net1 proto kernel metric 256 pref medium?

[mlguerrero12]

Thanks @chdxD1! Indeed, this is a bug.