Docker-通过其公共IP访问同一台机器上的另一个容器，而无需Docker链接

Question

On a VPS with a static, publicly routable IP, I have a simple web server running (on port 8080) in a container that exports port 8080 ( -p 0.0.0.0:8080:8080 ).

If I spin up another container on the same box and try to curl <public ip of host>:8080 it resolves the address, tries to connect but fails when making the request (it just hangs).

From the host's shell (outside containers), curl <public ip of host>:8080 succeeds.

Why is this happening? My feeling is that, somehow, the virtual network cards fail to communicate with each other. Is there a workaround (besides using docker links)?

Answer 1

According to Docker's advanced networking docs ( http://docs.docker.io/use/networking/ ): "Docker uses iptables under the hood to either accept or drop communication between containers."

As such, I believe you would need to setup inbound and outbound routing with iptables. This article gives a solid description of how to do so: http://blog.codeaholics.org/2013/giving-dockerlxc-containers-a-routable-ip-address/