Diun VS hadolint

Thanks, I used to use it. I moved to using diun to just notify of updates but not apply them though.

https://crazymax.dev/diun/ and docker compose

Similar to Watchtower but without the option to auto-update containers, just notifying is diun. But imo it does that better and more reliable than Watchtower does. You can get notified by Email, Discord, Pushover, Telegram and many more options.

If your apps are container images, then there are tools like diun, watchtower and whatsupdocker, those can watch the image repository (like Docker Hub) and notify you if a new/updated image has been found. Some can even download and auto-update for you, but that comes at some risk of course.

You might want to have a look at https://crazymax.dev/diun/ which is purpose built for what you're trying to do (notify when an update is available, but not install).

Watchtower is inferior to a project like DIUN this way. Because with double you can actually be notified by newer image versions and act accordingly. But automatic updates (which latest is aswell) are bad practice.

diun is very similar to that, but it doesnt auto-update, just notifies but does that very well imo.

I use https://crazymax.dev/diun/ to send notifications of new images. I also hook it into webbooks with CI for mirroring images, but you should be able to use something like portainer webhooks to auto pull images.

To skip the "move your scripts to standalone files" step some devs don't like, consider something like https://github.com/hadolint/hadolint which runs Shellcheck over inline scripts within Containerfiles.

This is neat :)

I love going and making containers smaller and faster to build.

I don't know if it's useful for alpine, but adding a --mount=type=cache argument to the RUN command that `apk add`s might shave a few seconds off rebuilds. Probably not worth it, in your case, unless you're invalidating the cached layer often (adding or removing deps, intentionally building without layer caching to ensure you have the latest packages).

Hadolint is another tool worth checking out if you like spending time messing with Dockerfiles: https://github.com/hadolint/hadolint

With Depot, we make use of two Dockerfile linters, hadolint and a set of Dockerfile linter rules that Semgrep has written to make a bit of a smarter Dockerfile linter.

# Download hadolint wget https://github.com/hadolint/hadolint/releases/download/v2.12.0/hadolint-Linux-x86_64 # Download SHA256 checksum wget https://github.com/hadolint/hadolint/releases/download/v2.12.0/hadolint-Linux-x86_64.sha256 # Validate the checksum sha256sum -c hadolint-Linux-x86_64.sha256 # Make the file executable chmod + ./hadolint-Linux-x86_64 # Rename the file mv hadolint-Linux-x86_64 hadolint

The most common linter I've seen and used it Hadolint, which does: https://github.com/hadolint/hadolint/wiki/DL3002 I didn't bother checking to see if alternatives also support this as well though.

Some discussion on that here:

https://github.com/koalaman/shellcheck/issues/58

The hadolint project does shell checking for Dockerfiles and it uses shellcheck:

https://github.com/hadolint/hadolint

So the approach is definitely feasible, but you do need a new project and probably it needs to be written in Haskell.

how does this compare to something like hadolint?

Also, have you run across Hadolint for linting? https://github.com/hadolint/hadolint