So I've got a Plex server running on my Docker swarm!! If I kill a node magically it'll start Plex somewhere else. This is great! Now comes the fun part...
With old-school containers I would just port forward port 32400 on my router to the server that was running Plex and it would work find. Now that Plex can run in multiple different places I need to figure out how to forward the port to some static resource. I could use HAProxy to bind some bridge interface and run it on every node to provide failover...but I'd like to see if there's an easier way to accomplish this.
What's the best way to forward ports to services in Docker Swarm?
Port forwarding is built into the new swarm mode. There's a section on load balancing in the documentation:
The swarm manager uses ingress load balancing to expose the services you want to make available externally to the swarm. The swarm manager can automatically assign the service a PublishedPort or you can configure a PublishedPort for the service in the 30000-32767 range.
External components, such as cloud load balancers, can access the service on the PublishedPort of any node in the cluster whether or not the node is currently running the task for the service. All nodes in the swarm cluster route ingress connections to a running task instance.
Swarm mode has an internal DNS component that automatically assigns each service in the swarm a DNS entry. The swarm manager uses internal load balancing to distribute requests among services within the cluster based upon the DNS name of the service.
The following article discusses how to integrate a proxy load balancer into the docker engine