Painless Docker - 2nd Edition

Running Commands in Containers

Sometimes, after starting a container, you may want to run additional commands inside it. These commands are usually useful for debugging, exploration and administration tasks (like migrating databases). In this case, a useful command is docker exec.

To better understand how docker exec works, let's first create and start a container:

docker run -d --name my_ubuntu_container ubuntu sleep infinity

At this point, we have a running Ubuntu container that is executing the sleep infinity command to keep it alive. Now we can use docker exec to run additional commands:

# List files in the root directory of the container
docker exec