Can multiple Docker containers run using the same host/port?

Question

Been looking into using Docker for a REST service project. One question I have is whether we could use Docker to run multiple versions of the service on the same host/port.

For example, I want to have an endpoint at {myserver}:8080/v1/ and another at {myserver}:8080/v2/.

If it's relevant at all, these would be Java:8 based Docker images constructed with a java jar on the Spring Boot REST framework.

Is this possible with Docker containers?

Answer 1

You can run both containers using different host ports, and use a haproxy/nginx/varnish (native or inside another container) listening to the host port, and redirecting to the right container based on the URL.

Answer 2

This is as much a question about the way tcp ports work as the way docker works. In the same way that two applications can't bind to the same tcp port, neither can two docker containers.

As @Sergei Rodionov points out SO_REUSEPORT can be used to allow multiple processes to share the same tcp port (and this can be specified when launching your java application). I don't think this will work across containers.