Changes to contrib collector release process, and latest tag

[puckpuck]

With 0.42.0 of the collector contrib release came about some changes that were not communicated.

The 0.42.0 image has a different binary name, going from otelcolcontrib to otelcol-contrib. Though the entry point should handle this, it is still a change that will cause pain to some deployments.

The latest tag image isn't the same as the 0.42.0 image. latest still has the old binary name, and the image itself is over 50MB, while the 0.42.0 image is around 29MB in size.

Tagging @jpkrohling on this per this CNCF slack thread: https://cloud-native.slack.com/archives/C01N6P7KR6W/p1641846859039500

[jpkrohling]

While unfortunate, I would just keep the binary name change. Changing it back would potentially break people again.

I think the image size is OK, but I have yet to check why this is different. And about the latest, we could certainly fix this for 0.43. @silverlyra, it should be relatively easy to do with the new Go structs, right?

[puckpuck]

Should the binary name change be documented in a changelog?

[Aneurysm9]

I suspect that the size change is related to the change in debug symbol stripping noted in #58.

[jpkrohling]

Should the binary name change be documented in a changelog?

It might be too late for that already, but doing it retroactively is indeed possible: https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CHANGELOG.md#v0420

[silverlyra]

And about the latest, we could certainly fix this for 0.43.

@jpkrohling If I’m understanding this issue right, the fix in this repo would be update DockerManifest and add a second identical manifest with the latest tag in its name instead of {{ .Version }}.

For the core otelcol distribution, I think that would suffice, as the current published latest is out of date anyway:

But as this issue notes, otelcol-contrib has a recent but completely different latest image:

I don’t know where that image is published from, but that’d need to be turned off as well.

[silverlyra]

Ah I’m thinking about it a bit more and keeping the latest tag up to date is not quite so straightforward. We’d only want to update it when publishing a tag that is newer than the current latest by a semver comparison.

That’d either need to be done outside of goreleaser, or we’d need to stop relying on a pre-generated and committed .goreleaser.yml and switch to generating it on demand.

[jpkrohling]

I don’t know where that image is published from, but that’d need to be turned off as well.

This was being published by the otel-collector core repository before we switched to building the distribution here in this repository. I understand that the job that published the image there got disabled already.

Ah I’m thinking about it a bit more and keeping the latest tag up to date is not quite so straightforward. We’d only want to update it when publishing a tag that is newer than the current latest by a semver comparison.

Good point. While this is true for the moment, it might not be true after v1. Is that handled by the Docker GitHub Action? We could have a workflow that is kicked on tags, publishing images to latest only (if this case is handled by that action).

[mx-psi]

The latest tag is now reliably updated, and we decided to keep the binary rename so I am closing this :)