[Feat] Operator: HPA config enabled

cmd/web-hooks/internal/handler/handler.go

@@ -377,8 +377,8 @@ func validateWorkloads(ca *v1alpha1.CAPApplication, cavObjNew *v1alpha1.CAPAppli
 			return workloadPortValidate
 		}
 
-		if workloadPortValidate := checkWorkloadPodDistruptionBudget(&workload); !workloadPortValidate.allowed {
-			return workloadPortValidate
+		if workloadPDBValidate := checkWorkloadPodDistruptionBudget(&workload); !workloadPDBValidate.allowed {
+			return workloadPDBValidate
 		}
 
 		// get count of workload names

internal/controller/common_test.go

@@ -43,6 +43,7 @@ import (
 	istiofake "istio.io/client-go/pkg/clientset/versioned/fake"
 	istioscheme "istio.io/client-go/pkg/clientset/versioned/scheme"
 	appsv1 "k8s.io/api/apps/v1"
+	autoscalingv2 "k8s.io/api/autoscaling/v2"
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
 	discoveryv1 "k8s.io/api/discovery/v1"
@@ -671,8 +672,10 @@ func compareExpectedWithStore(t *testing.T, resource []byte, c *Controller) erro
 		actual, err = c.kubeClient.(*k8sfake.Clientset).Tracker().Get(gvk.GroupVersion().WithResource("endpointslices"), mo.GetNamespace(), mo.GetName())
 	case *policyv1.PodDisruptionBudget:
 		actual, err = c.kubeClient.(*k8sfake.Clientset).Tracker().Get(gvk.GroupVersion().WithResource("poddisruptionbudgets"), mo.GetNamespace(), mo.GetName())
+	case *autoscalingv2.HorizontalPodAutoscaler:
+		actual, err = c.kubeClient.(*k8sfake.Clientset).Tracker().Get(gvk.GroupVersion().WithResource("horizontalpodautoscalers"), mo.GetNamespace(), mo.GetName())
 	default:
-		return fmt.Errorf("unknown expected object type")
+		return fmt.Errorf("unknown expected object type (common_test might need to be extended): %T", expected)
 	}
 
 	if err == nil {

internal/controller/reconcile-capapplicationversion.go

@@ -18,6 +18,7 @@ import (
 	"github.com/sap/cap-operator/internal/util"
 	"github.com/sap/cap-operator/pkg/apis/sme.sap.com/v1alpha1"
 	appsv1 "k8s.io/api/apps/v1"
+	autoscalingv2 "k8s.io/api/autoscaling/v2"
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
 	networkingv1 "k8s.io/api/networking/v1"
@@ -713,9 +714,63 @@ func (c *Controller) updateDeployment(ca *v1alpha1.CAPApplication, cav *v1alpha1
 		}
 	}
 
+	// Create HPA for the deployment if configured
+	if err == nil && workload.DeploymentDefinition.HorizontalPodAutoscaler != nil {
+		err = c.createOrUpdateHorizontalPodAutoscaler(deploymentName, workload, cav, ca)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	return workloadDeployment, doChecks(err, workloadDeployment, cav, workload.Name)
 }
 
+func (c *Controller) createOrUpdateHorizontalPodAutoscaler(deploymentName string, workload *v1alpha1.WorkloadDetails, cav *v1alpha1.CAPApplicationVersion, ca *v1alpha1.CAPApplication) error {
+	hpaName := deploymentName
+	// Get the HPA which should exist for this deployment
+	hpa, err := c.kubeClient.AutoscalingV2().HorizontalPodAutoscalers(cav.Namespace).Get(context.TODO(), hpaName, metav1.GetOptions{})
+	// If the resource doesn't exist, we'll create it
+	if k8sErrors.IsNotFound(err) {
+		hpa, err = c.kubeClient.AutoscalingV2().HorizontalPodAutoscalers(cav.Namespace).Create(context.TODO(), newHorizontalPodAutoscaler(deploymentName, ca, cav, workload), metav1.CreateOptions{})
+		if err == nil {
+			util.LogInfo("Horizontal Pod Autoscaler created successfully", string(Processing), cav, hpa, "version", cav.Spec.Version)
+		}
+	}
+	return doChecks(err, hpa, cav, workload.Name)
+}
+
+func newHorizontalPodAutoscaler(deploymentName string, ca *v1alpha1.CAPApplication, cav *v1alpha1.CAPApplicationVersion, workload *v1alpha1.WorkloadDetails) *autoscalingv2.HorizontalPodAutoscaler {
+	hpaName := deploymentName
+	labels := copyMaps(workload.Labels, getLabels(ca, cav, CategoryWorkload, string(workload.DeploymentDefinition.Type), getWorkloadName(cav.Name, workload.Name), true))
+
+	// Copy the HPA spec defined in the CRD and set the scale target ref to the deployment created for this workload.
+	// As scaleTargetRef from k8s client is required, we used our own copy without that field and set it here to avoid users having to set it.
+	hpaSpec := autoscalingv2.HorizontalPodAutoscalerSpec{
+		ScaleTargetRef: autoscalingv2.CrossVersionObjectReference{
+			Kind:       "Deployment",
+			Name:       deploymentName,
+			APIVersion: "apps/v1",
+		},
+		MinReplicas: workload.DeploymentDefinition.HorizontalPodAutoscaler.MinReplicas,
+		MaxReplicas: workload.DeploymentDefinition.HorizontalPodAutoscaler.MaxReplicas,
+		Metrics:     workload.DeploymentDefinition.HorizontalPodAutoscaler.Metrics,
+		Behavior:    workload.DeploymentDefinition.HorizontalPodAutoscaler.Behavior,
+	}
+
+	return &autoscalingv2.HorizontalPodAutoscaler{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      hpaName,
+			Namespace: cav.Namespace,
+			OwnerReferences: []metav1.OwnerReference{
+				*metav1.NewControllerRef(cav, v1alpha1.SchemeGroupVersion.WithKind(v1alpha1.CAPApplicationVersionKind)),
+			},
+			Labels:      labels,
+			Annotations: copyMaps(workload.Annotations, getAnnotations(ca, cav, true)),
+		},
+		Spec: hpaSpec,
+	}
+}
+
 func (c *Controller) createOrUpdatePodDisruptionBudget(workload *v1alpha1.WorkloadDetails, cav *v1alpha1.CAPApplicationVersion, ca *v1alpha1.CAPApplication) error {
 	pdbName := getWorkloadName(cav.Name, workload.Name)
 	// Get the PDB which should exist for this deployment

internal/controller/reconcile-capapplicationversion_test.go

@@ -1015,3 +1015,49 @@ func TestCAV_PodDisruptionBudget(t *testing.T) {
 		},
 	)
 }
+
+func TestCAV_HorizontalPodAutoscalerError(t *testing.T) {
+	reconcileTestItem(
+		context.TODO(), t,
+		QueueItem{Key: ResourceCAPApplicationVersion, ResourceKey: NamespacedResourceKey{Namespace: "default", Name: "test-ca-01-cav-v1"}},
+		TestData{
+			description: "capapplication version - horizontal pod autoscaler error scenario",
+			initialResources: []string{
+				"testdata/common/domain-ready.yaml",
+				"testdata/common/cluster-domain-ready.yaml",
+				"testdata/common/ca-services.yaml",
+				"testdata/common/credential-secrets.yaml",
+				"testdata/capapplicationversion/cav-hpa.yaml",
+				"testdata/capapplicationversion/services-ready.yaml",
+				"testdata/capapplicationversion/service-content-job-completed.yaml",
+			},
+			backlogItems: []string{},
+			expectError:  true,
+			mockErrorForResources: []ResourceAction{
+				{Verb: "get", Group: "autoscaling", Version: "v2", Resource: "horizontalpodautoscalers", Namespace: "default", Name: "*"},
+			},
+		},
+	)
+}
+
+func TestCAV_HorizontalPodAutoscaler(t *testing.T) {
+	reconcileTestItem(
+		context.TODO(), t,
+		QueueItem{Key: ResourceCAPApplicationVersion, ResourceKey: NamespacedResourceKey{Namespace: "default", Name: "test-ca-01-cav-v1"}},
+		TestData{
+			description: "capapplication version - horizontal pod autoscaler",
+			initialResources: []string{
+				"testdata/common/domain-ready.yaml",
+				"testdata/common/cluster-domain-ready.yaml",
+				"testdata/common/ca-services.yaml",
+				"testdata/common/credential-secrets.yaml",
+				"testdata/capapplicationversion/cav-hpa.yaml",
+				"testdata/capapplicationversion/services-ready.yaml",
+				"testdata/capapplicationversion/service-content-job-completed.yaml",
+			},
+			backlogItems:      []string{},
+			expectError:       false,
+			expectedResources: "testdata/capapplicationversion/expected/cav-hpa-ready.yaml",
+		},
+	)
+}

internal/controller/testdata/capapplicationversion/cav-hpa.yaml

@@ -0,0 +1,86 @@
+apiVersion: sme.sap.com/v1alpha1
+kind: CAPApplicationVersion
+metadata:
+  creationTimestamp: "2022-03-18T22:14:33Z"
+  generation: 1
+  annotations:
+    sme.sap.com/btp-app-identifier: btp-glo-acc-id.test-cap-01
+    sme.sap.com/owner-identifier: default.test-cap-01
+  labels:
+    sme.sap.com/btp-app-identifier-hash: f20cc8aeb2003b3abc33f749a16bd53544b6bab2
+    sme.sap.com/owner-generation: "2"
+    sme.sap.com/owner-identifier-hash: 66ee9c21adb3f78f19a2c376acc179437a96b5cb
+  finalizers:
+    - sme.sap.com/capapplicationversion
+  name: test-ca-01-cav-v1
+  namespace: default
+  ownerReferences:
+    - apiVersion: sme.sap.com/v1alpha1
+      blockOwnerDeletion: true
+      controller: true
+      kind: CAPApplication
+      name: test-ca-01
+      uid: 3c7ba7cb-dc04-4fd1-be86-3eb3a5c64a98
+  resourceVersion: "11371108"
+  uid: 5e64489b-7346-4984-8617-e8c37338b3d8
+spec:
+  capApplicationInstance: test-ca-01
+  registrySecrets:
+    - regcred
+  version: 0.0.1
+  workloads:
+    - name: cap-backend-service
+      consumedBTPServices:
+        - cap-uaa
+        - cap-service-manager
+        - cap-saas-registry
+      deploymentDefinition:
+        type: Service
+        image: docker.image.repo/srv/server:latest
+        ports:
+          - name: server
+            port: 4004
+            appProtocol: http
+          - name: api
+            port: 8000
+            appProtocol: http
+          - name: metrics
+            port: 4005
+            appProtocol: http
+        replicas: 3
+        horizontalPodAutoscaler:
+          minReplicas: 1
+          maxReplicas: 5
+    - name: content-job
+      consumedBTPServices:
+        - cap-uaa
+      jobDefinition:
+        type: Content
+        image: docker.image.repo/content/cap-content:latest
+    - name: app-router
+      consumedBTPServices:
+        - cap-uaa
+        - cap-saas-registry
+      deploymentDefinition:
+        type: Service
+        image: docker.image.repo/approuter/approuter:latest
+        ports:
+          - name: server
+            port: 5000
+            appProtocol: http
+        replicas: 3
+        horizontalPodAutoscaler:
+          minReplicas: 2
+          maxReplicas: 4
+  serviceExposures:
+    - subDomain: router
+      routes:
+        - workloadName: app-router
+          port: 5000
+    - subDomain: api
+      routes:
+        - workloadName: cap-backend-service
+          port: 8000
+          path: /api
+status:
+  state: Processing