Routing containers through a different gateway

I am really having a tough time figuring out how to route a container (or a group of containers) through a different gateway.
My network is set up that I want the rancher server to route through x.x.x.1 for most traffic, but some containers will need to route through x.x.x.254.

1: is there a way to do this at the container setup level… (i.e. adjust the bridge or management network to use .254 as the gateway)
2: is there a way to put custom persistent iptables rules on my Rancher host such that I can manually route the container through the correct gateway?

Anyone have this mystery figured out already?

Did you try configuring the custom routes on the host directly? Rancher takes care of routing only between containers on network.