[feat] - add validation for existing selectors

internal/analyzers/prometheus.go

@@ -68,8 +68,11 @@ func RunPrometheusAnalyzer(ctx context.Context, clientSets *k8sutil.ClientSets,
 
 	if !namespaceSelectorStatus {
 		if len(nilNamespaceSelectors) > 0 {
-			fmt.Printf("No %s is defined, defaulting to the same namespace of Prometheus\n", strings.Join(nilNamespaceSelectors, ", "))
-			// TODO check if selectors are already created
+			//fmt.Printf("No %s is defined, defaulting to the same namespace of Prometheus\n", strings.Join(nilNamespaceSelectors, ", "))
+			checkSelectorsCreated := checkServiceDiscovery(ctx,clientSets,namespace)
+			if !checkSelectorsCreated{
+				fmt.Printf("No Service Selectors are created yet")
+			}
 		}
 	} else {
 			fmt.Println("All namespace selectors are either empty or properly defined.")
@@ -86,8 +89,11 @@ func RunPrometheusAnalyzer(ctx context.Context, clientSets *k8sutil.ClientSets,
 
 	if !serviceSelectorStatus{
 		if emptyServiceSelectors!= nil {
-			fmt.Printf("Selectors are defined: %s\n", strings.Join(emptyServiceSelectors, ", "))
-			// TODO check if selectors are already created
+			//fmt.Printf("Selectors are defined: %s\n", strings.Join(emptyServiceSelectors, ", "))
+			checkServiceSelectorsCreated := checkServiceDiscovery(ctx,clientSets,namespace)
+			if !checkServiceSelectorsCreated{
+				fmt.Printf("No Service Selectors are created yet")
+			}
 		}
 	} 
 
@@ -246,3 +252,36 @@ func checkPrometheusServiceSelectorsStatus(serviceSelectors map[string]interface
 	}
 	return true, nil
 }
+
+func checkServiceDiscovery(ctx context.Context, clientSets *k8sutil.ClientSets, namespace string) bool {
+	var existingSelectors []string
+	podMonitor, err := clientSets.MClient.MonitoringV1().PodMonitors(namespace).List(ctx, metav1.ListOptions{})
+	if err != nil {
+		fmt.Errorf("Error listing PodMonitors: %v\n", err)
+	}
+	if len(podMonitor.Items) == 0 {
+		existingSelectors = append(existingSelectors,"podMonitor")
+	}	
+
+	serviceMonitor, err := clientSets.MClient.MonitoringV1().ServiceMonitors(namespace).List(ctx, metav1.ListOptions{})
+	if err != nil {
+		fmt.Errorf("Error listing PodMonitors: %v\n", err)
+	}
+	if len(serviceMonitor.Items) == 0 {
+		existingSelectors = append(existingSelectors,"serviceMonitor")
+	}
+
+	probe, err := clientSets.MClient.MonitoringV1().Probes(namespace).List(ctx, metav1.ListOptions{})
+	if err != nil {
+		fmt.Errorf("Error listing PodMonitors: %v\n", err)
+	}
+	if len(probe.Items) == 0 {
+		existingSelectors = append(existingSelectors,"probe")
+	}		
+	// TODO add scrapeconfig check
+
+	if len(existingSelectors) == 0 {
+		return false
+	}
+	return true
+}