Request to Add Metrics Instrumentation for Mux & Chi

[jwafle]

Background

Package Link: package instrumentation already exists for tracing.

Why can this instrumentation not be included in the package itself?

These packages already have tracing instrumentation in opentelemetry-go-contrib. I am seeking further guidance on whether the inclusion of HTTP metrics should be pursued in this repository, or if these packages should begin migration to the packages themselves.

N.B. I have already opened issues in the package repositories to raise issues about OTEL instrumentation:
chi: go-chi/chi#937
mux: gorilla/handlers#257

Why can this instrumentation not be hosted in a dedicated repository?

See above. Asking for clarification on this matter.

Proposed Solution

Either:

1. Begin migration of tracing instrumentation to the individual libraries, and continue adding metrics instrumentation from there.
2. Continue in opentelemetry-go-contrib and add metrics instrumentation here.

Tracing

n/a, already exists

Metrics

Instruments

All metrics instrumentation that I would like implemented for these packages are well defined in the semantic conventions: https://opentelemetry.io/docs/specs/semconv/http/http-metrics/

Prior Art

• https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/instrumentation/github.com

Tasks

• Code complete:
  • Comprehensive unit tests.
  • End-to-end integration tests.
  • Tests all passing.
  • Instrumentation functionality verified.
• Documented
  • Added to the OpenTelemetry Registry
  • README included for the module describing high-level purpose.
  • Complete documentation of all public API including package documentation.
  • Instrumentation documentation updated.
• Examples
  • Dockerfile file to build example application.
  • docker-compose.yml to run example in a docker environment to demonstrate instrumentation.