add prometheus metrics for apis

[drinktee]

Preflight Checklist

• I could not find a solution in the existing issues, docs, nor discussions
• I have joined the ZITADEL chat

Describe your problem

It need to add prometheus metrics for apis. Just like http://xxxx:8888/metrics

Describe your ideal solution

add a middleware for metric

Version

No response

Additional Context

No response

[muhlemmer]

You can add your own middleware using options:

https://pkg.go.dev/github.com/zitadel/oidc/v3/pkg/op#WithHTTPMiddleware

We already have OpenTelemetry included in the package for metrics. If you define a tracer in your main package and pass the context, you should get metrics out of the OIDC package.

[muhlemmer]

It is also possible to configure OTEL to export to prometheus using this package: https://pkg.go.dev/go.opentelemetry.io/otel/exporters/prometheus

All the base infrastructure is already present in OIDC. The package consumer needs to setup otel with the desired exporter, in this case prometheus. Such setup is not in the scope of the OIDC library. Therefore I will now close this issue.