Dual ISP policy routing appears to have broken docker networking for mail-receiver for community.osm.org

[Firefishy]

The mail-receiver container for community.osm.org is unable to connect to the IPs for community.osm.org

Likely an issue with policy routing or similar.

[Firefishy]

As a workaround I have manually host hacked community.openstreetmap.org in the container to point to 172.17.0.4 (Docker special IP for host)

[Firefishy]

This appears to fix the routing issue:

sudo ip route add 172.17.0.0/16 dev docker0 table 100

Need to backport it into chef.

[tomhughes]

Ah so it's actually the route back to 172.17 that is the problem, not the outgoing route from from 172.17 to the public address. That explains why I was having so much trouble fixing it.

I suspect that an additional rule would also work:

sudo ip rule add to 172.17.0.0/16 table main priority 50

[tomhughes]

Yes that seems to work so I've implemented it in openstreetmap/chef@e397f00.