Docker: Connecting to a Remote Host

I for one, maybe not everyone, but I for a long time though that to be able to communicate with a docker instance I had to be on that box.

First, after digging around I found the DOCKER_HOST environment variable, which served it purpose, and allowed me to connect to one or more of my docker hosts;

$ export DOCKER_HOST="ssh://me@dockerhost
$ docker ps
CONTAINER ID IMAGE...
1b2e8e4a546a casperghst42/pms-docker...
4de622e79fa6 casperghst42/httpserver...
...

Now after (unsuccessly) having looked at VS Code and it's Docker extension (which as of writing is broken in more than one way), I discovered Docker Contexts.

Instead of using DOCKER_HOST one should use docker contexts, which allow to setup multiple hosts to connect to.

Example:

$ docker context ls
NAME         TYPE         DESCRIPTION
default      moby         Current DOCKER_HOST based
dockerhost   * moby
....

Setting up a new context is quite easy:

$ docker context create <contextname> --docker "host=ssh://<user>@<host>"

To switch between Docker contexts is also quite easy:

$ docker context use <contextname>

Docker is not always easy, until you run into the right explanation.