Docker Contexts

Using the host on each command that we use is redundant and error-prone. For example, a deployment may fail due to it reaching a different host because we omitted to specify the host when running the command and we executed a different command on our local host.

For this case, Docker Contexts can be of help.

By creating contexts, we can switch our Docker configuration to multiple contexts and pick the right context per case.

So, let’s create a context for our EC2 host:

$ docker context create ec2-remote --docker host=ssh://ec2-user@18.130.80.179

Although we have created the context, we are still in the default context. Let’s switch to the recently created context:

$ docker context use ec2-remote

Run the following command:

$ docker run -it --rm redis

Check the results on the server:

ssh ec2-user@18.130.80.179 docker ps
CONTAINER ID   IMAGE     COMMAND      ...