feat(logging): implement per-request logging middleware with access log

Signed-off-by: Noooste <83548733+Noooste@users.noreply.github.com>

backend/internal/middleware/logging.go

@@ -0,0 +1,82 @@
+package middleware
+
+import (
+	"time"
+
+	logpkg "Noooste/garage-ui/pkg/logger"
+
+	"github.com/gofiber/fiber/v3"
+	"github.com/rs/zerolog"
+)
+
+// LoggerLocalsKey is the fiber.Ctx.Locals key carrying the per-request logger.
+const LoggerLocalsKey = "logger"
+
+// Logging returns middleware that (1) builds a per-request zerolog.Logger
+// bound with request_id/method/path/remote_ip/user_agent, (2) injects it into
+// c.Context() so service layers can retrieve it via logger.FromCtx, and
+// (3) emits a single access-log line after the handler runs.
+//
+// The base logger is the one to derive from — typically the global zerolog
+// logger configured at startup. Tests pass a buffer-backed logger here.
+//
+// Access-log line fields: request_id, method, path, remote_ip, user_agent,
+// status, duration_ms, bytes_out. Skipped for /health and OPTIONS.
+// Level is chosen from status: >=500 error, >=400 warn, else info.
+func Logging(base zerolog.Logger) fiber.Handler {
+	return func(c fiber.Ctx) error {
+		requestID, _ := c.Locals(RequestIDLocalsKey).(string)
+
+		reqLogger := base.With().
+			Str("request_id", requestID).
+			Str("method", c.Method()).
+			Str("path", c.Path()).
+			Str("remote_ip", c.IP()).
+			Str("user_agent", c.Get("User-Agent")).
+			Logger()
+
+		c.Locals(LoggerLocalsKey, reqLogger)
+		c.SetContext(logpkg.IntoCtx(c.Context(), reqLogger))
+
+		start := time.Now()
+		err := c.Next()
+		duration := time.Since(start)
+
+		if skipAccessLog(c) {
+			return err
+		}
+
+		status := c.Response().StatusCode()
+		bytesOut := len(c.Response().Body())
+
+		evt := eventForStatus(&reqLogger, status)
+		evt.
+			Int("status", status).
+			Float64("duration_ms", float64(duration.Microseconds())/1000.0).
+			Int("bytes_out", bytesOut).
+			Msg("http_request")
+
+		return err
+	}
+}
+
+func skipAccessLog(c fiber.Ctx) bool {
+	if c.Method() == fiber.MethodOptions {
+		return true
+	}
+	if c.Path() == "/health" {
+		return true
+	}
+	return false
+}
+
+func eventForStatus(l *zerolog.Logger, status int) *zerolog.Event {
+	switch {
+	case status >= 500:
+		return l.Error()
+	case status >= 400:
+		return l.Warn()
+	default:
+		return l.Info()
+	}
+}