Feature: BuildKit support

[akatsukilelouch]

What are you trying to do?

Building local containers that utilize buildkit build backend. I've personally hit a need for it due to extensive use of RUN --mount type=cache. Without it, redownloading packages for building OCI via OCI (multi-stage builds) increases time of builds drastically. Not only that but it also decreases SSD expectancy and uses extra ingress.

Why should it be done this way?

Allows building with buildkit backend! I've skimmed over testcontainers community modules and found out that only node supports buildkit now and that rust supports it too via bollard. I am not sure what's the state with official Go and Java modules, but skimming over other modules' issues haven't shown any BuildKit related items.

I am by no means expert and I've not spent time tinkering with Docker API, but just putting version=2 in params in docker/api/build.py leads to docker.errors.BuildError: Syntax error - can't find = in "label.decode(\"utf-8\")". Must be of the form: name=value for me (it's an error from moby namespace from the host, for sure).

If that's an error that is local to my build configuration, then please edit this message to reflect that or notify me, that might be misleading.

If you can provide hints what might be an issue, I'd be able to look for a solution in a few days and try to implement it myself, because I need it.

[akatsukilelouch]

Well, there's the issue in docker-py. I think this issue is worth staying in this repository so people would stumble upon it right away when trying to use buildkit with python testcontainers.

[akatsukilelouch]

There's also python-on-whales Docker python client that supposedly works with BuildKit.

[akatsukilelouch]

There's also python-on-whales Docker python client that supposedly works with BuildKit.

I've attempted trying using python-on-whales instead of docker-py as the client package for docker but it uses local docker command line tool instead of docker API and that might be a major (breaking) change (I was midway through when I realized that).

As a temporary minor change workaround we could just add a local CLI-based docker buildx plugin wrapper instead, why not. I'll look what I can do with docker-py.

[akatsukilelouch]

It was an issue with buildkit, I've submitted a PR to it: moby/buildkit#6428.