Update and Cleanup

containrrr/watchtower is a service that monitors Docker images for updates, automatically applying them to running containers.

Automatic image updates + cleanup

compose.yaml

services:
  watchtower:
    image: containrrr/watchtower:latest
    # Automatic cleanup (removes older image pulls from wasting disk space):
    environment:
      - WATCHTOWER_CLEANUP=true
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

Updating only specific containers

The default watchtower service will check every 24 hours for any new image updates to pull, not only the images defined within your compose.yaml.

The images to update can be restricted with a custom command that provides a list of containers names and other config options. Configuration is detailed in the watchtower docs.

Manual cleanup

watchtower also supports running on-demand with docker run or compose.yaml via the --run-once option.

You can also directly invoke cleanup of Docker storage with:

• docker image prune --all
• docker system prune --all (also removes unused containers, networks, build cache).
• Avoid the --all option to only remove "dangling" content (eg: Orphaned images).