Notice that a tiny subset of github.com/prometheus/prometheus has been "vendored" in order to avoid an issue with transitive dependencies.

We only need a dependency on github.com/prometheus/prometheus/documentation/examples/custom-sd/adapter.

However, it depends on github.com/prometheus/prometheus/discovery, which brings all sd implementations, which results in a dependency nightmare (e.g., version of https://github.com/Azure/go-autorest conflicts with k8s.io/client-go).

That's why we opted for "vendoring" + manual editing to avoid transitive dependencies.