How to add artifacts from another image to ddev web-build?

[MurzNN]

I need to build a custom utility, using another image, and copy the results to the ddev web image.
So, I created a separate Dockerfile.xk6-elastic with the content:

FROM golang:1.20-alpine AS k6-build
WORKDIR $GOPATH/src/go.k6.io/k6
ADD . .
RUN apk --no-cache add git
RUN CGO_ENABLED=0 go install go.k6.io/xk6/cmd/xk6@latest
RUN CGO_ENABLED=0 xk6 build --with github.com/elastic/[email protected] --output /tmp/k6

# Adding "arg base-image"
ARG BASE_IMAGE
# Using "from as" construction
FROM $BASE_IMAGE AS ${BASE_IMAGE}_final
# Using "copy" construction
COPY --from=k6-build /tmp/k6 /usr/bin/k6
# End k6

But after restarting the ddev - I got the error:

failed to solve: circular dependency detected on stage: k6-build

How can I resolve this problem?

[MurzNN]

Seems this happens because ddev removes the line:

FROM $BASE_IMAGE AS ${BASE_IMAGE}_final

from the final compiled Dockerfile, here is the contents of the .ddev/.webimageBuild/Dockerfile:

### From user Dockerfile /home/alexey_korepov/projects/myproject/.ddev/web-build/Dockerfile.k6-elastic:
FROM golang:1.20-alpine AS k6-build
WORKDIR $GOPATH/src/go.k6.io/k6
ADD . .
RUN apk --no-cache add git
RUN CGO_ENABLED=0 go install go.k6.io/xk6/cmd/xk6@latest
RUN CGO_ENABLED=0 xk6 build --with github.com/elastic/[email protected] --output /tmp/k6

# Adding "arg base-image"
# Using "from as" construction
# Using "copy" construction
COPY --from=k6-build /tmp/k6 /usr/bin/k6
# End k6

So the line just disappeared!

[MurzNN]

@rfay Not so exotic from my point of view ;) I just need to compile a k6 utility to use inside ddev - here is their original Dockerfile https://github.com/elastic/xk6-output-elasticsearch/blob/main/Dockerfile

Maybe you could advise a more easy way to compile a tool in Golang, to integrate it into the ddev-web container?

[stasadev]

I don't use such builds, so I can't recommend something better. If this k6 is used in many DDEV projects, it might be worth building it somewhere else and then adding it to the container via curl/wget.

[rfay]

You can certainly compile in a Dockerfile; Just install golang or use related technique in the Dockerfile. But @stasadev 's suggestion is probably better. There are several add-ons that build things like PHP extensions, which is harder.

[MurzNN]

You can certainly compile in a Dockerfile; Just install golang or use related technique in the Dockerfile.

Yes, but this way will keep a lot of garbage after compiling, but I need only the single compiled file as an artifact, with no other files. This is because the approach of using a separate container to compile is much better.

If this k6 is used in many DDEV projects, it might be worth building it somewhere else and then adding it to the container via curl/wget.

Yes, downloading the built binary is much easier, but it is not provided by the maintainers. And while downloading, I need to also match the correct architecture (linux-amd64, macos-arm64, etc), but with compilation - it compiles to the current architecture automatically.

So my described approach seems to work well, only duplicating the actions looks not so good.

[rfay]

Yes, but this way will keep a lot of garbage after compiling, but I need only the single compiled file as an artifact, with no other files. This is because the approach of using a separate container to compile is much better.

That's actually not true; there are many docker build examples where the intended target is kept and nothing else.

Anyway, glad you have a solution!