support building docker images using BuildKit

[helmlover]

The claim "Docker [...] Works out of the box." is no longer true.
That is because docker now uses BuildKit per default, while the BuildKit Dockerfile syntax is not supported when building docker images with testcontainers-node (e.g. with GenericContainer.fromDockerfile(buildContext).build())

When building a Dockerfile containing BuildKit-features e.g.

RUN--mount=type=cache,id=maven,target=/root/.m2/repository mvn --batch-mode --no-transfer-progress dependency:resolve dependency:resolve-plugins

through testcontains-node (with export 'DEBUG=testcontainers*'), the output currently looks like:

2023-05-12T08:52:02.265Z testcontainers:build [localhost/43420fa7dc4a:2c9e53cede2c] {"errorDetail":{"message":"the --mount option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled"},"error":"the --mount option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled"}

Exporting export DOCKER_BUILDKIT=1 does not change the problem/output.

PS: Sibling issue in testcontainers-java: testcontainers/testcontainers-java#2857

[cristianrgreco]

Hi @helmlover, see the parent issue: docker/for-linux#1136. BuildKit does not yet seem supported over the Docker HTTP API, as such is only currently available via the CLI.

[osa0805]

Hi,
Is there a plan to add this support ?

[praveensvsrk]

+1, we need support for this....curious if there a workaround available to achieve the RUN cache like functionality without buildkit features?

[silh]

It looks like what's necessary is a support for creating a session and running it in dockerode. Go implementation for that in terraform was added here - https://github.com/kreuzwerker/terraform-provider-docker/pull/387/files#diff-4596d40531ae2e21f6074d104e6dc7317537946b56d95df847c9209dfbe30fceR329 The session run code is here

[mikeseese]

Note that the API does support using BuildKit with the version option: this issue has fixed in the correct repo: https://github.com/moby/moby/blob/master/api/swagger.yaml#L8722-L8731

The linked upstream issue (docker/for-linux#1136) is on a deprecated/seemingly abandoned repo.

[silh]

The main problem is with setting up a websocket connect for the session which is required for version 2. IIRC, dockerode (or its underling library docker-modem) didn't support that.

[mikeseese]

I'm not sure about that, or the requirements for this module (as I'm just bubbling up the finding as I saw others waiting on an issue on an abandoned repo), but I am able to use dockerode's buildImage with { version: "2" } as an option and BuildKit is used.

[schummar]

I don't think that's right. Passing { version: "2" } to dockerode's buildImage doesn't do anything. The build still fails when using some BuildKit dependent feature like --mount=type=cache.

I quickly looked into it at some point and my impression was that is really not straight forward using build version 2 on the docker api. I am not sure about any of this but my impression was: You to have to implement a gRPC server on your side, then hijack the http connection to start a session which allow the docker daemon to make calls on your end!? It's baffling api design if you ask me 😁

[mikeseese]

@schummar I guess my verification was that prior to adding { version: "2" } to the build options object, I would receive the error during building my image:

the --chmod option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled

which referenced a COPY --chmod=755 ... line in my Dockerfile

and after adding it, I was able to build the image successfully 🤷 I can close my DefinitelyTyped PR if adding it doesn't support all BuildKit features

[silh]

@mikeseese that's still a valid option and should be added there. It exists in docker's API description - https://docs.docker.com/engine/api/v1.45/#tag/Image/operation/ImageBuild