Change log format to integrate with GCP

api/controller/controller.go

@@ -4,6 +4,7 @@ import (
 	"log/slog"
 
 	"github.com/gofiber/fiber/v2"
+	slogfiber "github.com/samber/slog-fiber"
 )
 
 type Controller interface {
@@ -31,6 +32,6 @@ func HandlerPrintf(c *fiber.Ctx, severity int, message string, v ...any) {
 		logger = slog.Error
 	}
 
-	args := append([]any{"method", c.Method(), "path", c.Path(), "request-id", c.Context().UserValue("request-id")}, v...)
+	args := append([]any{"request-id", slogfiber.GetRequestID(c)}, v...)
 	logger(message, args...)
 }

api/main.go

@@ -17,7 +17,21 @@ import (
 )
 
 func main() {
-	logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
+	// Replace keys to allow GCP to parse logs correctly
+	// https://cloud.google.com/logging/docs/structured-logging
+	opts := slog.HandlerOptions{
+		ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
+			switch a.Key {
+			case "level":
+				a.Key = "severity"
+			case "msg":
+				a.Key = "message"
+			}
+			return a
+		},
+	}
+
+	logger := slog.New(slog.NewJSONHandler(os.Stdout, &opts))
 	slog.SetDefault(logger)
 
 	slog.Info("Starting API service")