Validate a Container With Docker Ls

Is a Docker container available on a registry? Here’s how I’d check, right from the CLI:

docker image ls <container-name>

You could use this when doing an upgrade. Perhaps we’re upgrading Debian to Bookworm, and we don’t know which Python versions are available on our new OS version. This command will tell you.

$ docker image ls python:3.10.12-slim-bookworm # Exists 😊
IMAGE                          ID             DISK USAGE   CONTENT SIZE   EXTRA
python:3.10.12-slim-bookworm   4d440b214e44        244MB         52.3MB

$ docker image ls python:3.10-slim-bookworm # Doesn't exist 😔
IMAGE   ID             DISK USAGE   CONTENT SIZE   EXTRA

Both return exit code 0, success. You can force exit code 1 for scripting with docker inspect <container-name>.

See docker image ls --help for more info.