Disable metrics endpoint access logs by default

Switch off the metrics endpoint access logs as it's unlikely they're
going to be of significant value, but allow them to be re-enabled by the
command-line or configuration file.

config/serve.yaml

@@ -11,4 +11,5 @@ endpoints:
 
 logging:
   json: true
+  metrics: false
   level: debug

internal/cmd/serve.go

@@ -124,6 +124,10 @@ func init() {
 	flags.Int("shutdown-timeout", shutdownTimeout, "Timeout (in seconds) to wait for requests to finish")
 	_ = viper.BindPFlag("endpoints.timeouts.shutdown", flags.Lookup("shutdown-timeout"))
 
+	viper.SetDefault("logging.metrics", false)
+	flags.Bool("log-metrics", false, "Set whether to log metrics port requests")
+	_ = viper.BindPFlag("logging.metrics", flags.Lookup("log-metrics"))
+
 	rootCmd.AddCommand(serveCmd)
 }
 

internal/serve/metrics/main.go

@@ -27,7 +27,10 @@ type Service struct {
 func NewService() *Service {
 	router := gin.New()
 
-	router.Use(middleware.Logger())
+	if viper.GetBool("logging.metrics") {
+		router.Use(middleware.Logger())
+	}
+
 	router.Use(middleware.Prometheus("metrics"))
 	router.Use(gin.Recovery())
 

internal/serve/middleware/logger.go

@@ -21,11 +21,6 @@ func Logger() gin.HandlerFunc {
 					http.StatusUnauthorized,
 					http.StatusNotFound,
 				),
-				// slogg.IgnorePath(
-				// 	"/alive",
-				// 	"/healthz",
-				// 	"/metrics",
-				// ),
 			},
 		},
 	)

schemas/serve.json

@@ -171,6 +171,9 @@
         "level": {
           "$ref": "#/$defs/logging-level"
         },
+        "metrics": {
+          "$ref": "#/$defs/logging-metrics"
+        },
         "json": {
           "$ref": "#/$defs/logging-json"
         }
@@ -181,9 +184,15 @@
       "type": "string",
       "enum": ["debug", "info", "warning", "error"]
     },
+    "logging-metrics": {
+      "description": "Set whether or not to log requests to the metrics port",
+      "type": "boolean",
+      "default": false
+    },
     "logging-json": {
       "description": "Set whether or not to use JSON-based structured logging",
-      "type": "boolean"
+      "type": "boolean",
+      "default": false
     }
   },
   "type": "object",