Thank you. I hope you can find some usefulness in it. You can also do things by compose labels. As well as dynamically at runtime. Either interactively or as arguments.

This question is usually asked a lot.

This started as a project to prove that you could check for updates without first pulling every new image to compare against, while that’s not why it kept get getting traction my original answer to this question still seems true:

From Watchtower Docs - Arguments

Due to Docker API limitations the latest image will still be pulled from the registry.

And:

Do not pull new images. When this flag is specified, watchtower will not attempt to pull new images from the registry. Instead it will only monitor the local image cache for changes

It’s also a different approach. With dockcheck you’d run it and then make the choice what you’ll update there and then. Selectively choosing exactly what containers to update at the moment. Or have it completely unattended auto update a selection of images.

With the notifications, you can get notified and then have a sitdown and auto-update what you choose.

It’s just different workflows and options.

The upcoming release will also add a new option to backup the image being updated and then autoprune old backups after N days. To allow for easy rollback if a new image breaks.

Thank you! Yeah I’m the same - if the first thing I see on a project page is some picture or video or output of what it’s about I’m much more intrigued to read on.

Tooting my own horn here and I know it’s not a 1-1 replacement, but as others mentioned some great alternatives (diun, cup, wud) I’d like to suggest dockcheck.

Very nice! Now posted here: https://github.com/mag37/dockcheck/discussions/146

Thats really nice! Thank you so much for the writeup.

Would you mind if I added this as a discussion (crediting you and this post!) in the github project? Or if you’d like to copypaste it yourself to get the credit and be a part of the discussion.

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It’s a different approach. This project started as a proof of concept - just to show that it’s possible to check for updates without pulling the whole image first (which is how Watchtower does it).

Then it evolved to orchestrate granular automatic updates with a bunch of extra functionality - while still adhering to the core goal of keeping it simple and lightweight.

Thank you! Oh! That’s pretty cool, do you mind sharing bits of how this is done? Would be nice to incorporate into a notify-template in the future.

Thank you!

I sadly don’t have too much insights in the other alternatives, I try to not compare too much - maybe I should study them a bit more to understand the wider picture. There’s a few more I forgot to mention; renovate and dependabot.

While I think all those tools are great and have functionality that my project cant fulfill - I strive to keep dockcheck simple and lightweight. Options and functionality have been bolted on bit by bit while still trying to have it as simple as possible in its core functions - so a user could just download the main script dockcheck.sh and run it to list updates and optionally update. Everything else is optional, extras.

I guess it depends on what you’re looking for. If you’d like a GUI or more in depth setup or reporting - I’d look elsewhere, but if you’d like simplicity and maybe schedule it to notify you when there’s updates available - my project may be the thing.

So my answer would be yes: if you’re running docker compose this project is very newbie friendly and easy to get going!