Observability

Every request goes through, from the outermost:

1. the otelhttp instrumentation,
2. the request log,
3. the panic recovery,
4. the routing, the middlewares and the handler.

Traces

Each request gets a server span:

• named after the route: GET /users/{id}, or just the method when no route matches,
• with the HTTP semantic conventions attributes: http.route, http.request.method, http.response.status_code, url.path, client.address, body sizes…
• with an error status for 5xx responses.

The incoming trace context (traceparent, baggage…) is extracted with the application propagator, so the span continues the trace of the caller. Spans created in handlers with r.Context() are children of the request span.

Metrics

The HTTP server metrics of the semantic conventions, with the http.route, http.request.method and http.response.status_code attributes:

Metric	Description
http.server.request.duration	Duration of the requests
http.server.request.body.size	Size of the request bodies
http.server.response.body.size	Size of the response bodies

Logs

Each request is logged as http request, at error level for 5xx responses and info level otherwise, with:

Attribute	Example
method	GET
path	/users/42
route	GET /users/{id}
status	200
response_size	512
duration	1.2ms

The log is correlated with the request span. Disable request logs with httpserver.log.enabled: false.

Panics

A panic in a handler or a middleware is logged at error level, with its stack, and answered with a 500 if nothing was written yet. The span and the request log record the 500. A panic(http.ErrAbortHandler) aborts the response, as with the standard server.

Exclude paths

Requests to health checks or other noisy endpoints can be excluded from spans, metrics and request logs, with Go regular expressions matched against the request path:

httpserver:
  observability:
    exclude:
      - "^/livez$"
      - "^/readyz$"