Editing a file stored on a container volume in production is a very bad idea. You should not do it and pass all configuration through your container orchestrator. Using a single node Docker Swarm for test purposes, it can be a huge time saver though.

Here’s how to do it. Ensure that your DOCKER_HOST environment is set such that running docker volume ls will show the volume storing the file you want to edit (let’s call this volume myvol). Accessing the file is actually very easy by running

docker run --rm -it -v myvol:/data ubuntu bash

You’ll find the content of the volume under the directory /data. You might first need to install your preferred editor if the image you run does not include it.