docker exec · Knowledge & Memory Center

Get a shell inside

SHELL

1docker exec -it <container> sh

2# or, if the image has bash:

3docker exec -it <container> bash

4

5# run one command without a shell

6docker exec <container> <command>

Flag reference

SHELL

1-it # interactive shell with a TTY

2-u root # run as a specific user

3-w /app # working directory for the command

4-e KEY=value # extra env var for this command only

5-d # run the command in the background

Examples

SHELL

1# Open a shell (bash first, sh on Alpine)

2docker exec -it <container> bash

3docker exec -it <container> sh

4

5# One-off commands

6docker exec <container> env

7docker exec <container> cat /etc/hosts

8

9# Database consoles

10docker exec -it db psql -U postgres

11docker exec -it cache redis-cli

12

13# As root, to install a debugging tool

14docker exec -u root -it <container> sh

Only works on a running container. For a crashed one use docker logs, or start a debug copy with docker run --rm -it --entrypoint sh <image>
Minimal images (Alpine, distroless) often have no bash; distroless has no shell at all
Anything you change or install is lost when the container is recreated: fix the Dockerfile instead

!

exec starts a new process next to PID 1; exiting the shell does not stop the container.