hadolint VS Moby

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

Having been featured in our February 2023, and January 2024 Release Radars, Moby is the original Linux Container runtime. This new version adds a bunch of changes to the Docker CLI and Moby itself with additional features. There's bug fixes and enhancements, with the main thing for users to be on the look out for containers that were created using Docker Engine 25.0.0. These containers might have duplicate MAC addresses, and thus must be recreated. The same goes for those containers created with Moby 25.0+ and with user defined MAC addresses. Read up on all these changes in the release notes.

Formlabs does this as well for their 3d printers, my earliest encounter of this was when Docker started getting popular: https://github.com/moby/moby/blob/master/pkg/namesgenerator/...

Try to use moby instead since that is the engine in Docker.

https://github.com/moby/moby

> Podman is designed to help with this by providing stronger default security settings compared to Docker. Features like rootless containers, user namespaces, and seccomp profiles, while available in Docker, aren't enabled by default and often require extra setup.

Seccomp has been enabled by default since 2015: https://github.com/moby/moby/pull/18780

It is true that Rootless isn't enabled by default but its "extra setup" can be done with a single command (`dockerd-rootless-setuptool.sh install`)

Perhaps.

Thing is, https://github.com/moby/moby/blob/670bc0a46c4ca03b75f1e72f73... is using https://github.com/mistifyio/go-zfs which features code like `out, err := zfsOutput("get", "-H", key, d.Name)` (Source: https://github.com/mistifyio/go-zfs/blob/master/zfs.go#L315) to get a single zfs property.

Somebody chose to use a library as abstraction that looks good but is implemented as a MVP (nothing wrong with that). "In the future, we hope to work directly with libzfs" should have raised an alarm somewhere, though.

AppArmor can restrict /proc and this is even used by docker: https://github.com/moby/moby/blob/master/contrib/apparmor/te...