don't use empty path as label for LAPI hits metrics (#4106)

Author: blotus

pkg/apiserver/controllers/v1/metrics.go

@@ -30,9 +30,13 @@ func PrometheusMachinesMiddleware() gin.HandlerFunc {
 	return func(c *gin.Context) {
 		machineID, _ := getMachineIDFromContext(c)
 		if machineID != "" {
+			fullPath := c.FullPath()
+			if fullPath == "" {
+				fullPath = "invalid-endpoint"
+			}
 			metrics.LapiMachineHits.With(prometheus.Labels{
 				"machine": machineID,
-				"route":   c.FullPath(),
+				"route":   fullPath,
 				"method":  c.Request.Method,
 			}).Inc()
 		}
@@ -45,9 +49,13 @@ func PrometheusBouncersMiddleware() gin.HandlerFunc {
 	return func(c *gin.Context) {
 		bouncer, _ := getBouncerFromContext(c)
 		if bouncer != nil {
+			fullPath := c.FullPath()
+			if fullPath == "" {
+				fullPath = "invalid-endpoint"
+			}
 			metrics.LapiBouncerHits.With(prometheus.Labels{
 				"bouncer": bouncer.Name,
-				"route":   c.FullPath(),
+				"route":   fullPath,
 				"method":  c.Request.Method,
 			}).Inc()
 		}
@@ -60,8 +68,13 @@ func PrometheusMiddleware() gin.HandlerFunc {
 	return func(c *gin.Context) {
 		startTime := time.Now()
 
+		fullPath := c.FullPath()
+		if fullPath == "" {
+			fullPath = "invalid-endpoint"
+		}
+
 		metrics.LapiRouteHits.With(prometheus.Labels{
-			"route":  c.FullPath(),
+			"route":  fullPath,
 			"method": c.Request.Method,
 		}).Inc()
 		c.Next()