Add back support for Go 1.19 when using Jaeger as a library

[mx-psi]

Which problem is this PR solving?

• Relates to [Feature]: Migrate to go 1.20  #4202

Short description of the changes

This partially reverts #4206 and fully reverts #4291 and #4293.

On the OpenTelemetry Collector project we aim to provide support for all officially supported Go versions. Per Go's support policy, Go 1.19 will remain a supported Go version until Go 1.21 is released.

Since we take a dependency on Jaeger as a library, we would prefer Jaeger to remain compatible with Go 1.19 as a library to be able to keep it updated.

This patch does not revert some changes on #4206; Jaeger binaries would continue to be built with Go 1.20 and benefit from all performance and security improvements that the 1.20 release cycle offers. It does impose the requirement that new code is compatible with Go 1.19 (which sounds okay to me since there was no specific need for Go 1.20 mentioned on the related issues, the only obvious downside is delaying the removal of some helper code).

Signed-off-by: Pablo Baeyens pablo.baeyens@datadoghq.com

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: +0.03 🎉

Comparison is base (6ab3f01) 97.05% compared to head (8de19fa) 97.08%.

❗ Current head 8de19fa differs from pull request most recent head db35d53. Consider uploading reports for the commit db35d53 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4328      +/-   ##
==========================================
+ Coverage   97.05%   97.08%   +0.03%     
==========================================
  Files         300      300              
  Lines       17697    17697              
==========================================
+ Hits        17176    17182       +6     
+ Misses        419      414       -5     
+ Partials      102      101       -1     

Flag	Coverage Δ
unittests	97.08% <ø> (+0.03%)	⬆️

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see 3 files with indirect coverage changes

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[mx-psi]

@yurishkuro I would love to know if this is something you (as the author/approver of some of the reverted PRs) and the Jaeger project would be willing to accept before I continue working on it. I would need to fix some unit tests, but otherwise this is the extent of the changes needed to add back support for Go 1.19. Would you mind chiming in? Also pinging @jpkrohling whose opinion can be valuable here.

[yurishkuro]

I'd be fine if this was only the go.mod change, but rolling back so many changes doesn't make sense to me. And frankly neither does the OTEL collector policy - it's not a library where last two versions policy makes sense, collector is a binary, you should be able to upgrade the runtime as you see fit.

[mx-psi]

@yurishkuro

I'd be fine if this was only the go.mod change, but rolling back so many changes doesn't make sense to me

To be clear, the rest of the changes are just "don't use errors.Join and use the previous thing", but I understand that this is bigger than expected, I will close the PR.

neither does the OTEL collector policy - it's not a library where last two versions policy makes sense, collector is a binary, you should be able to upgrade the runtime as you see fit.

The Collector is consumed as a library for a wide variety of use cases. This includes downstream distros, OpenTelemetry Collector builder users, vendor-specific observability agents like the Datadog Agent or the Grafana Agent or tooling. It's even used as a library by Jaeger itself :)

[yurishkuro]

I opened #4329 to decide if we want to institute similar policy going forward.