Docker-compose pub-sub Faye server won't publish over network

I have a Rails 3 application that is dependant on private_pub. In my attempt to dockerize this application everything seems to be working as expected except my Faye container. I know my application is able to connect to the container but it appears that Faye is failing to publish.

I asked this same question on StackOverflow awhile ago but have gotten no answers so I’ll bump it here.