docker-exec - Man Page

Run a command in a running container

Examples (TL;DR)

Enter an interactive shell session on an already-running container: docker exec --interactive --tty container_name /bin/bash
Run a command in the background (detached) on a running container: docker exec --detach container_name command
Select the working directory for a given command to execute into: docker exec --interactive -tty --workdir path/to/directory container_name command
Run a command in background on existing container but keep stdin open: docker exec --interactive --detach container_name command
Set an environment variable in a running bash session: docker exec --interactive --tty --env variable_name=value container_name /bin/bash
Run a command as a specific user: docker exec --user user container_name command