Usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...] Run a command in a running container Options: -d, --detach Detached mode: run command in the background --detach-keys Override the key sequence for detaching a container -e, --env=[] Set environment variables --help Print usage -i, --interactive Keep STDIN open even if not attached --privileged Give extended privileges to the command -t, --tty Allocate a pseudo-TTY -u, --user Username or UID (format: <name|uid>[:<group|gid>])
The docker exec command runs a new command in a running container.
The command started using docker exec only runs while the container's primary process (PID 1) is running, and it is not restarted if the container is restarted.
docker exec on a running containerFirst, start a container.
$ docker run --name ubuntu_bash --rm -i -t ubuntu bash
This will create a container named ubuntu_bash and start a Bash session.
Next, execute a command on the container.
$ docker exec -d ubuntu_bash touch /tmp/execWorks
This will create a new file /tmp/execWorks inside the running container ubuntu_bash, in the background.
Next, execute an interactive bash shell on the container.
$ docker exec -it ubuntu_bash bash
This will create a new Bash session in the container ubuntu_bash.
docker exec on a paused containerIf the container is paused, then the docker exec command will fail with an error:
$ docker pause test test $ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 1ae3b36715d2 ubuntu:latest "bash" 17 seconds ago Up 16 seconds (Paused) test $ docker exec test ls FATA[0000] Error response from daemon: Container test is paused, unpause the container before exec $ echo $? 1