Cli: build natively on the cross compile architectures

[andrewhsu]

Description

Would like the ability to build natively on the cross compile architectures, i.e. arm, amd64, s390x, ppc64le.

Steps to reproduce the issue:

On an arm machine:

$ make -f docker.Makefile binary

Describe the results you received:

Dockerfile used to build the binary is x86_64 only:

panic: standard_init_linux.go:175: exec user process caused "exec format error" [recovered]
    panic: standard_init_linux.go:175: exec user process caused "exec format error"

Describe the results you expected:

A valid native binary in the build dir.

Additional information you deem important (e.g. issue happens only occasionally):

Workaround for now is to cross-compile the other architectures on an x86_64 machine:

$ make -f docker.Makefile cross

[andrewhsu]

/cc @dnephin @seemethere

[dnephin]

How important is it that we re-use the binary target? Would it be ok to have a binary-arch-native target?

We could add a new Dockerfile like this:

Dockerfile.multiarch

ARG    ARCH
FROM   $ARCH/golang:1-8.3
WORKDIR /go/src/github.com/docker/cli

And use:

• https://hub.docker.com/r/s390x/golang/
• https://hub.docker.com/r/ppc64le/golang/
• https://hub.docker.com/r/arm32v7/golang/ (v6 also exists)

[andrewhsu]

@dnephin A binary-arch-native target would be fine.

I suppose we just have to be mindful if you are on a mac and run make binary-archive-native. The make target would have to detect running on a mac and build the mac binary as a cross compile in a linux container.

[tophj-ibm]

A multi-arch repo also works pretty well here.

I don't know if there is any plans for an "official" one, but I used tianon's trollin repo and changed the FROM in dockerfiles/Dockerfile.dev to trollin/golang and that works.

[dnephin]

I believe this pattern should also support windows images.

[thaJeztah]

@andrewhsu @tophj-ibm with the golang images now being multi arch; is there any adjustment needed in this repository?

[dnephin]

It looks like the -alpine version is not multi-arch just yet (alpine is still a WIP). Hopefully that will be done soon and everything will just work.

[tophj-ibm]

@thaJeztah We are still waiting on alpine, and then golang:x-alpine to be multiarch (waiting on z). Once that happens I don't think anything will have to change here.

[thaJeztah]

Oh; yes, forgot we're using the Alpine version here

[tophj-ibm]

alpine + golang:1.8.5-alpine3.6 is multi-arch now, so this should work on all the supported linux/arch combinations. Just tested master on ppc64le and everything looks 👍

[seemethere]

@dnephin this is probably good to close

[dnephin]

Thanks! I'm happy with this solution.