Add support for linux/s390x architecture

[bwalk-at-ibm]

The s390x CPU architecture is the base for IBM zSeries (aka mainframe) systems. It is beneficial for users of this platform to have a supported way to install pre-compiled binaries for the OpenTelemetry collector in a Linux environment. This issue and associated pull requests will enable the building of all relevant binary artifacts for linux/s390x as part of the regular CI pipeline.

IBM has performed tests internally to ensure successful build (via cross-compilation) and runtime (on native platform) integrity of the OpenTelemetry collector (core and contrib) via the unit test suites and specific use-cases.

For more information and discussion please refer to the initial feature request issue (#378).

[jpkrohling]

We need this done before on the core and contrib repositories before adding to -releases, so that we are sure the code at least compiles once we are ready to perform a release.

[bwalk-at-ibm]

IIUC, we wait for the merge until the PRs for core and contrib have been merged, right? Or is there anything else required from my side?

[jpkrohling]

Looks like EasyCLA is still not happy about this one.

[bwalk-at-ibm]

Looks like EasyCLA is still not happy about this one.

I have refreshed it, don't know why it expired(?).

[codeboten]

Looks like goreleaser is failing for s390x, any idea? https://github.com/open-telemetry/opentelemetry-collector-releases/actions/runs/6157223841/job/16732668333?pr=384#step:7:60

[bwalk-at-ibm]

Hmm, I'm not that familiar with goreleaser but I can dig into it. But from what I understand in the error message, the build fails with installing ca-certificates in the Docker build image, which I can not reproduce on a native s390x machine:

$ podman run -it --rm alpine:3.16
Resolved "alpine" as an alias (/etc/containers/registries.conf.d/000-shortnames.conf)
Trying to pull docker.io/library/alpine:3.16...
Getting image source signatures
Copying blob e5761c1ed80a done
Copying config 16c78d841b done
Writing manifest to image destination
Storing signatures
/ # apk --update add ca-certificates
fetch https://dl-cdn.alpinelinux.org/alpine/v3.16/main/s390x/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.16/community/s390x/APKINDEX.tar.gz
(1/1) Installing ca-certificates (20230506-r0)
Executing busybox-1.35.0-r17.trigger
Executing ca-certificates-20230506-r0.trigger
OK: 6 MiB in 15 packages
/ # uname -m
s390x

I also didn't hit this when testing the cross-compile/build on x86 prior to sending the PR but let me verify this.

On second thought, looks like something went wrong with the cross-compile setup:

#6 ERROR: process "/bin/sh -c apk --update add ca-certificates" did not complete successfully: exit code: 1
------
 > [certs 2/2] RUN apk --update add ca-certificates:
0.618 exec /bin/sh: exec format error
------

That looks like it's trying to execute an s390x-executable in a non-s390x environment.

Seems we don't install the s390x version for QEMU in the pipeline:

Found it. Let's try again.

[codeboten]

Thanks for fixing @bwalk-at-ibm, to return to @jpkrohling's comment, is the plan to add this platform to the list of platforms in the contrib repo as well?

[bwalk-at-ibm]

Thanks for fixing @bwalk-at-ibm, to return to @jpkrohling's comment, is the plan to add this platform to the list of platforms in the contrib repo as well?

That's the idea. Here's the PR open-telemetry/opentelemetry-collector-contrib#25139.

[codeboten]

The contrib & core PRs have been merged. Thanks @bwalk-at-ibm 👍🏻

[bwalk-at-ibm]

Thanks a lot!