Arch Linux

mouseman

Member

From: Outta nowhere

Registered: 2014-04-04

Posts: 291

policy based routing with cgroups

On one of my machines I've set the default gateway to a router that goes out over a VPN. There is one process (maybe more in the future), syncthing-relaysrv, that I want to go out over a different gateway. Syncthing-relaysrv does not seem to work via the VPN gateway. Besides, I don't want it to run via the VPN anyway.

I've setup a cgroup based on this page.

When I spawn a new bash prompt and echo its process ID to tasks in this cgroup, I can check my external IP from that bash prompt and confirm it is working. I can remove the PID from the file and redo the check to see the VPN IP address.

When I add the PID from the syncthing-relaysrv process (I checked with ps aux|grep syncting and from the systemctl status syncthhing-relay where it lists its PID too), after some seconds the status will list the following message:

syncthing-relaysrv[17244]: 2018/04/14 13:44:35 pool.go:61: https://relays.syncthing.net/endpoint unknown response type from server 400

When I change the gateway to bypass the VPN and restart syncthing relay service, it will say

syncthing-relaysrv[18911]: 2018/04/14 14:46:02 pool.go:54: Joined https://relays.syncthing.net/endpoint rejoining in 48m0s

I can't seem to figure out why syncthing-relaysrv does not want to work with the gateway set via iptables/cgroup, while other processes seem to work fine (bash).

Any ideas why this might be and how I can solve this issue?

Thanks.