Add a resource detector for Gitlab CICD

[chameleon82]

Fixes for Gitlab CI: #6759

This PR adds a resource detector for Gitlab CI which sets values according to to semantic conventions for cicd](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/attributes-registry/cicd.md) and vcs resources:

cicd.pipeline.name
cicd.pipeline.task.run.id
cicd.pipeline.task.name
cicd.pipeline.task.type
cicd.pipeline.run.id
cicd.pipeline.task.run.url.full
vcs.repository.ref.name
vcs.repository.ref.type
vcs.repository.change.id
vcs.repository.url.full

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: chameleon82 / name: Aleksandr Nekrasov (819ab2d, 4e282e8, 2eddc5a)

[flc1125]

You can adjust this kind of format. semconv.CICDPipelineNameKey.String("xxxxx")

[flc1125]

os.Setenv be changed to t.Setenv

[flc1125]

We might need to add a configuration here: versions.yaml

Of course, the specific location to add it might need to be evaluated by @open-telemetry/go-approvers.

---

Don't forget there are two similar files:

• https://github.com/open-telemetry/opentelemetry-go-contrib/blob/daafaee72ec56a090b0cc1408293d31ecbc17e75/detectors/gcp/version.go
• https://github.com/open-telemetry/opentelemetry-go-contrib/blob/daafaee72ec56a090b0cc1408293d31ecbc17e75/detectors/gcp/version_test.go

[chameleon82]

added as experimental version, but can't find version for the another component https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/detectors/azure/azurevm. not sure if this is expected for experimental versions

[dmathieu]

Did you go through our new instrumentation docs?
https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/instrumentation/README.md#new-instrumentation

Could you develop on why this needs to be a go-contrib instrumentation, and can't be owned by you, or GitLab?

[pellared]

First of all, thanks for your will in contributing to OTel 👍

This proposes a new module and it lacks a code owner.
This PR won't be accepted (and possibly even reviewed) if no code owner is found.

Please check https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/CONTRIBUTING.md#code-owners for more information.

[pellared]

Did you go through our new instrumentation docs? https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/instrumentation/README.md#new-instrumentation

Could you develop on why this needs to be a go-contrib instrumentation, and can't be owned by you, or GitLab?

I created #6762

I think that we cannot expect contributors to find https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/instrumentation/README.md#new-instrumentation

[chameleon82]

Thanks @dmathieu and @pellared for pointing those good points.
Yes, it is not directly related to instrumentation (which can be very different in the case - worker/runner or go test framework). And as I see current work on cicd semantic, it can be a good idea to have commonly used systems (github/gitlab) covered with contrib module.

I'm looking for both cases (gitlab pipelines otel observability and go test observability with tracing) and will be happy to contribute as much I can into it, but as currently not a part of a working group and do not participate SIG's - may not be a proper maintainer.

Let's ask @dnsmichi, @sguyon opinion on this as Gitlab representatives.