hadolint VS bocker

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

A (joke?) one-liner I came up with while thinking about solutions to centralized container management across multiple SSH hosts. Shame on me.

The name is inspired by bocker [0], albeit this doesn't re-implement docker-compose in bash, I found it to be fitting enough.

I'd love to see someone come up with a smarter and/or shorter way to do this.

[0] https://github.com/p8952/bocker

When I did a talk about docker I also wanted to show a bit of what it does under the hood without going through all the layers and without too much details. This ~120 lines of shell script is really good in providing just an intro into what's needed for containers: https://github.com/p8952/bocker/blob/master/bocker

i tried it and like the concnpt, but until it can be launched via a systemd userspace service (without previously manually booting it) among other problems i will keep using docker (or bocker)

> But you couldn't reimplement podman in a few hundred lines of code.

You don't even need a few hundred: https://github.com/p8952/bocker

And then there's 'dokku' which IIRC, started as a bash version of Heroku.

> Not all ideas have the same quality.

They really do. I've heard all kinds of things in my career, but almost none I would want to dedicate a portion of my life building. Not because they are bad ideas or won't work, but because of the person with the idea or it just didn't interest me. Those people went on to be moderately successful (like hundreds of millions worth) but I'm glad I wasn't on that ride.

Bocker is in this same category...docker clone in bash that's helpful in seeing what's really happening underneath with nsenter, namespaces, network bridging, cgroups, etc.

https://github.com/p8952/bocker

Docker implemented in around 100 lines of bash: https://github.com/p8952/bocker

This is the most mindblowing example for enterprise security teams that think Docker is a new threat on a single tenant Linux host.

No, buddies, all this stuff is already there. If you were fine with your visibility before*, you're still fine. Go find a real problem while we play with our developer dopamine.

* NARRATOR: They shouldn't have been.

Bocker[1] does a reasonably good job of showing the value of Docker was mostly in Docker hub.

[1] https://github.com/p8952/bocker

There is a cool project I've seen called "bocker" (https://github.com/p8952/bocker) which is something of a proof of concept of implementing Docker with bash, which speaks a bit to how Docker is indeed in many ways an amalgam of lower level primitives (such as chroot as you mentioned). Pretty neat!