internal/api/middleware.go - master - t3/s3-server

internal/api/middleware.go
80 строк2 KB
Ivan
end-to-end logging
25 июл 2026, 00:10
25 июл 2026, 00:102107e02
package api

import (
	"log/slog"
	"net/http"
	"time"

	"github.com/google/uuid"
)

// isValidRequestID checks that the request ID is a non-empty alphanumeric + hyphen string up to 64 chars.
func isValidRequestID(rid string) bool {
	if rid == "" || len(rid) > 64 {
		return false
	}
	for _, c := range rid {
		if (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '-' {
			continue
		}
		return false
	}
	return true
}

// RequestIDMiddleware reads or generates a request/correlation ID.
// Accepts client-supplied X-Request-ID (validated). Otherwise generates a UUIDv4.
// Sets the response header and adds it to the request context.
func RequestIDMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		rid := r.Header.Get("X-Request-ID")
		if !isValidRequestID(rid) {
			rid = uuid.NewString()
		}
		w.Header().Set("X-Request-ID", rid)
		ctx := WithRequestID(r.Context(), rid)
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

// statusRecorder wraps http.ResponseWriter to capture the status code and byte count.
type statusRecorder struct {
	http.ResponseWriter
	status  int
	written int64
}

func (r *statusRecorder) WriteHeader(code int) {
	r.status = code
	r.ResponseWriter.WriteHeader(code)
}

func (r *statusRecorder) Write(b []byte) (int, error) {
	if r.status == 0 {
		r.status = http.StatusOK
	}
	n, err := r.ResponseWriter.Write(b)
	r.written += int64(n)
	return n, err
}

// LoggingMiddleware logs every request with method, path, status, duration, bytes, and request_id.
func LoggingMiddleware(logger *slog.Logger) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			start := time.Now()
			sr := &statusRecorder{ResponseWriter: w, status: http.StatusOK}

			next.ServeHTTP(sr, r)

			logger.Info("request",
				"method", r.Method,
				"path", r.URL.Path,
				"status", sr.status,
				"bytes", sr.written,
				"duration", time.Since(start).String(),
				"request_id", RequestIDFromContext(r.Context()),
			)
		})
	}
}