fix: Handle gateway case where the baseline is missing or not labelled (

#245)

The CLI gateway command crashes if there is no baseline namespace. The
baseline namespace does not get labelled properly if it already exists.
This change fixes those issues.

kardinal-cli/cmd/root.go

@@ -569,7 +569,7 @@ var gatewayCmd = &cobra.Command{
 		}
 
 		if err := deployment.StartGateway(ctx, hostFlowIdMap); err != nil {
-			log.Fatal("An error occurred while creating a gateway", err)
+			log.Fatalf("An error occurred while creating a gateway: %v", err)
 		}
 	},
 }

kardinal-cli/deployment/gateway.go

@@ -72,25 +72,28 @@ func StartGateway(ctx context.Context, hostFlowIdMap map[string]string) error {
 		return fmt.Errorf("an error occurred while creating a kubernetes client:\n %v", err)
 	}
 
-	for host, flowId := range hostFlowIdMap {
-		logrus.Printf("Starting gateway for host: %s", host)
+	// TODO move these values to a shared library between Kardinal Manager, Kontrol and Kardinal CLI
+	kardinalLabelKey := "kardinal.dev"
+	enabledKardinal := "enabled"
 
-		// TODO move these values to a shared library between Kardinal Manager, Kontrol and Kardinal CLI
-		kardinalLabelKey := "kardinal.dev"
-		enabledKardinal := "enabled"
+	namespaceLabels := map[string]string{
+		kardinalLabelKey: enabledKardinal,
+	}
 
-		namespaceLabels := map[string]string{
-			kardinalLabelKey: enabledKardinal,
-		}
+	namespaceList, err := client.GetNamespacesByLabels(ctx, namespaceLabels)
+	if err != nil {
+		return fmt.Errorf("failed to list namespaces from Kubernetes: %v", err)
+	}
+	if len(namespaceList.Items) == 0 {
+		return fmt.Errorf("cannot start gateway because no Kardinal namespace was found")
+	}
+	if len(namespaceList.Items) > 1 {
+		return fmt.Errorf("cannot start gateway because more than one Kardinal namespace was found")
+	}
+	baselineNamespace := namespaceList.Items[0]
 
-		namespaceList, err := client.GetNamespacesByLabels(ctx, namespaceLabels)
-		if err != nil {
-			return fmt.Errorf("failed to list namespaces from Kubernetes: %v", err)
-		}
-		if len(namespaceList.Items) > 1 {
-			return fmt.Errorf("cannot start gateway because more than one Kardinal namespace was found")
-		}
-		baselineNamespace := namespaceList.Items[0]
+	for host, flowId := range hostFlowIdMap {
+		logrus.Printf("Starting gateway for host: %s", host)
 
 		// Check for pods in the baseline namespace
 		err = assertBaselineNamespaceReady(client.GetClientSet(), flowId, baselineNamespace.Name)

kardinal-manager/kardinal-manager/cluster_manager/cluster_manager.go

@@ -386,7 +386,11 @@ func (manager *ClusterManager) ensureNamespace(ctx context.Context, name string)
 		value, found := existingNamespace.Labels[istioLabel]
 		if !found || value != enabledIstioValue {
 			existingNamespace.Labels[istioLabel] = enabledIstioValue
-			manager.kubernetesClient.clientSet.CoreV1().Namespaces().Update(ctx, existingNamespace, globalUpdateOptions)
+			existingNamespace.Labels[kardinalLabelKey] = enabledKardinal
+			_, err = manager.kubernetesClient.clientSet.CoreV1().Namespaces().Update(ctx, existingNamespace, globalUpdateOptions)
+			if err != nil {
+				return stacktrace.Propagate(err, "Failed to update Namespace: %s", name)
+			}
 		}
 	} else {
 		newNamespace := corev1.Namespace{