When creating a route-map, the ability to use the quagga "set src" action would be very useful as it allows to configure the preferred local source when the system generates packets.
So for a practical usage, lets say I have a 172.30.1.0/30 tunnel on which someone is routing a 126.96.36.199 public IP to me.
I can then set the 188.8.131.52 IP on a loopback, then configure the default route to 172.30.1.1 but when the system generates packets, it would use 172.30.1.2 as source. The solution is then to have a route-map in quagga :
access-list acl_to_gw permit 172.30.1.1/32
route-map RM_SET_SRC permit 10
match ip next-hop acl_to_gw
set src 184.108.40.206
But currently there is no way to get VyOS to generate that "set src" part.
Also need a way to have VyOS generate the "ip protocol static route-map RM_SET_SRC" part as well. Not sure if that's already possible or not.