Any way to use --build-context in buildkit:rootless

[xuannguyenhehe]

I need to use feature --build-context in docker (https://docs.docker.com/build/concepts/context/#use-cases-for-named-contexts)

But I try some ways but no anyone work.

I need mount from second context into Dockerfile.

Example: docker build --build-context proto=../proto
And in Dockerfile I will

COPY --from proto . ../../

Anyone help me pls :(

[tonistiigi]

How is this related to rootless. You are not providing any error messages or setup descriptions.

[JimmyPesto]

I tried a couple of different parameters passed to the buildctl-daemonless.sh build command with no success. Adding --opt build-context:proto=/path/to/proto does start the build process; however, when

COPY --from=proto ...

is executed, the build process is trying to fetch a Docker Hub image called "proto" instead of referencing the extra local context.

I have not been able to find any documentation on how to pass an extra build context so far. What would be the correct parameters for --build-context in buildctl-daemonless.sh build? Based on this, I could test it and share a more detailed example.

[tonistiigi]

--opt context:proto=local:proto --local proto=/path/to/proto

https://github.com/moby/buildkit/blob/master/docs/reference/buildctl.md#dockerfile-specific-options

[JimmyPesto]

Works exactly as expected. Thanks a lot for your feedback.