prometheus/storage/remote/otlptranslator/README.md

Copying from opentelemetry/opentelemetry-collector-contrib

This files in the prometheus/ and prometheusremotewrite/ are copied from the OpenTelemetry Project¹.

This is done instead of adding a go.mod dependency because OpenTelemetry depends on prometheus/prometheus and a cyclic dependency will be created. This is just a temporary solution and the long-term solution is to move the required packages from OpenTelemetry into prometheus/prometheus. We don't copy in ./prometheus through this script because that package imports a collector specific featuregate package we don't want to import. The featuregate package is being removed now, and in the future we will copy this folder too.

To update the dependency is a multi-step process:

1. Vendor the latest prometheus/prometheus@main into opentelemetry/opentelemetry-collector-contrib
2. Update the VERSION in update-copy.sh.
3. Run ./update-copy.sh.

Why copy?

This is because the packages we copy depend on the prompb package. While the package is relatively stable, there are still changes. For example, https://github.com/prometheus/prometheus/pull/11935 changed the types. This means if we depend on the upstream packages directly, we will never able to make the changes like above. Hence we're copying the code for now.

I need to manually change these files

When we do want to make changes to the types in prompb, we might need to edit the files directly. That is OK, please let @gouthamve or @jesusvazquez know so they can take care of updating the upstream code (by vendoring in prometheus/prometheus upstream and resolving conflicts) and then will run the copy script again to keep things updated.

---

1. https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/pkg/translator/prometheus and https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/pkg/translator/prometheusremotewrite ↩︎