podinfo/pkg/api/http/logging.go

package http

import (
	"net/http"

	"go.opentelemetry.io/otel/trace"
	"go.uber.org/zap"
)

type LoggingMiddleware struct {
	logger *zap.Logger
}

func NewLoggingMiddleware(logger *zap.Logger) *LoggingMiddleware {
	return &LoggingMiddleware{
		logger: logger,
	}
}

func (m *LoggingMiddleware) Handler(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fields := []zap.Field{
			zap.String("proto", r.Proto),
			zap.String("uri", r.RequestURI),
			zap.String("method", r.Method),
			zap.String("remote", r.RemoteAddr),
			zap.String("user-agent", r.UserAgent()),
		}

		spanCtx := trace.SpanContextFromContext(r.Context())
		if spanCtx.HasTraceID() {
			fields = append(fields, zap.String("trace_id", spanCtx.TraceID().String()))
		}

		m.logger.Debug(
			"request started",
			fields...,
		)
		next.ServeHTTP(w, r)
	})
}