services: Fix metric from not publishing

When the metric variable is defined as a global variable (within the
`var` scope at the package level), then it will be instantiated as a
NoOp metric. Once the metrics package is initialized, then all the
metrics variables will transition from NoOp metrics to a real metric
type. This problem occurred because the global variables instantiation
happened before the metrics package initialization.

This commit fixes it by using the metrics variable after the metrics
package has been initialized. We can assume it's been initialized when
the code executed is production ("live") code.

Fixes: #26511
Fixes: 978b27c ("Metrics: Add services metrics")
Signed-off-by: Chris Tarazi <chris@isovalent.com>

pkg/service/service.go

@@ -33,12 +33,6 @@ import (
 
 const anyPort = "*"
 
-var (
-	updateMetric = metrics.ServicesEventsCount.WithLabelValues("update")
-	deleteMetric = metrics.ServicesEventsCount.WithLabelValues("delete")
-	addMetric    = metrics.ServicesEventsCount.WithLabelValues("add")
-)
-
 // ErrLocalRedirectServiceExists represents an error when a Local redirect
 // service exists with the same Frontend.
 type ErrLocalRedirectServiceExists struct {
@@ -719,9 +713,9 @@ func (s *Service) upsertService(params *lb.SVC) (bool, lb.ID, error) {
 	}
 
 	if new {
-		addMetric.Inc()
+		metrics.ServicesEventsCount.WithLabelValues("add").Inc()
 	} else {
-		updateMetric.Inc()
+		metrics.ServicesEventsCount.WithLabelValues("update").Inc()
 	}
 
 	s.notifyMonitorServiceUpsert(svc.frontend, svc.backends,
@@ -1617,7 +1611,7 @@ func (s *Service) deleteServiceLocked(svc *svcInfo) error {
 		s.healthServer.DeleteService(lb.ID(svc.frontend.ID))
 	}
 
-	deleteMetric.Inc()
+	metrics.ServicesEventsCount.WithLabelValues("delete").Inc()
 	s.notifyMonitorServiceDelete(svc.frontend.ID)
 
 	return nil