CWATCH (pronounced "quatch" is short for "container watch" - as this project started out as a "how do I do that?" to monitor containers. It has since turned into an image watcher, but "cwatch" sounds better :)

As mentioned above, this started as a "how do I do that?" - and yes, other options are available (i.e. WatchTower) - but that wouldn't have taught me anything. This has been an end to end experiment in getting (re)used to GitHub, DockerHub, Dockerfile and some scripting.

CWATCH is currently defaulted to run at 1am every day. This will likely get made configurable later. In a punch you can edit /etc/crontabs/root after setup :)

It requires that /var/run/docker.sock be bind mounted.
It assumes that you are using the standard Docker Hub Registry for your images....

Volumes

• /var/run/docker.sock:/var/run/docker.sock:ro
• /tmp/cwatch.txt:/var/log/cwatch (optional)

Environment

• DEBUG - Can be set to 1 for verbose output. Defaults to 0
• DOCKER_REGISTRY - Set this to whatever Docker Registry host you need. Defaults to registry.hub.docker.com
• DOCKER_REGISTRY_SERVICE - Set this to whatever Docker Registry service host you need. Defaults to registry.docker.io
• DOCKER_AUTH_SERVICE - Set this to whatever Docker Auth host you need. Defaults to auth.docker.io

Once installed, CWATCH will run every 1am, outputting to it's docker log. You can see the output via docker logs cwatch or in the logs window if you use Portainer. It also writes logs to /var/log/cwatch - so you can mount that as a bind mount (see above) if you want a local file

Every 1am, CWATCH will run and check each container for a newer Docker Registry image, and advise if one is available.

• msmtp support is coming shortly (to send emails)
• Images with no obvious tag will default to "latest" - this may not be desirable in all instances