External_link networking issue

Hello everyone,

I would like to start by telling you I am by no means a Docker expert, so I may just be looking at this in the wrong way.

Anyway, my issue is as followed:
One of my compose containers has to read data from an external container (etcd). When this container is launched within the docker-compose.yml and linked to there is no issue (“etcd:2379” is accessible as a host). As soon as I externalize the etcd container (start it from outside the compose file) and replace the link with an external link ("- etcd:etcd") networking no longer works.

If you would like to see a docker-compose.yml please ask.

Kind regards,
Toon Sevrin


As very well documented external links in version 2 require at least one commonly shared network.

Hi @exorath, can you kindly explain how you specify a commonly shared network? I’m just getting started and I’m unable to specify commonly shared networks as each network gets prefixed with the project name and I therefore cannot specify a network in a different compose.

Is Flannel being used for networking? Typically Flannel would be used with etcd.