Merge pull request #176 from dannawang0221/add-object-mutator

Add mutator functions to allow modify the Kubernetes resources used b…

Author: k8s-ci-robot

populator-machinery/controller.go

@@ -78,7 +78,8 @@ const (
 	reasonPopulateOperationStartSuccess = "PopulateOperationStartSuccess"
 	reasonPopulateOperationFailed       = "PopulateOperationFailed"
 	reasonPopulateOperationFinished     = "PopulateOperationFinished"
-	reasonPVCCreationError              = "PopulatorPVCPrimeCreationError"
+	reasonPVCPrimeCreationError         = "PopulatorPVCPrimeCreationError"
+	reasonPVCPrimeMutatorError          = "reasonPVCPrimeMutatorError"
 	reasonWaitForDataPopulationFinished = "PopulatorWaitForDataPopulationFinished"
 	reasonStorageClassCreationError     = "PopulatorStorageClassCreationError"
 	reasonDataSourceNotFound            = "PopulatorDataSourceNotFound"
@@ -116,6 +117,7 @@ type controller struct {
 	referenceGrantSynced   cache.InformerSynced
 	podConfig              *PodConfig
 	providerFunctionConfig *ProviderFunctionConfig
+	mutatorConfig          *MutatorConfig
 	crossNamespace         bool
 	providerMetricManager  *ProviderMetricManager
 }
@@ -140,6 +142,9 @@ type VolumePopulatorConfig struct {
 	// ProviderFunctionConfig is the configuration for invoking provider functions. Either PodConfig or ProviderFunctionConfig should
 	// be specified. PodConfig and ProviderFunctionConfig can't be provided at the same time
 	ProviderFunctionConfig *ProviderFunctionConfig
+	// MutatorConfig is the configuration for invoking mutator functions. You can specify your own mutator functions to modify the
+	// Kubernetes resources used for volume population
+	MutatorConfig *MutatorConfig
 	// ProviderMetricManager is the manager for provider specific metric handling
 	ProviderMetricManager *ProviderMetricManager
 	// CrossNamespace indicates if the populator supports data sources located in namespaces different than the PVC's namespace.
@@ -189,6 +194,19 @@ type PopulatorParams struct {
 	Recorder     record.EventRecorder
 }
 
+type MutatorConfig struct {
+	// PvcPrimeMutator is the mutator function for pvcPrime. The function gets called to modify the PVC object before pvcPrime gets created.
+	PvcPrimeMutator func(PvcPrimeMutatorParams) (*corev1.PersistentVolumeClaim, error)
+}
+
+// PvcPrimeMutatorParams includes the parameters passing to the PvcPrimeMutator function
+type PvcPrimeMutatorParams struct {
+	// PvcPrime is the temporary PVC created by volume populator
+	PvcPrime *corev1.PersistentVolumeClaim
+	// StorageClass is the original StorageClass Pvc refer to
+	StorageClass *storagev1.StorageClass
+}
+
 func RunController(masterURL, kubeconfig, imageName, httpEndpoint, metricsPath, namespace, prefix string,
 	gk schema.GroupKind, gvr schema.GroupVersionResource, mountPath, devicePath string,
 	populatorArgs func(bool, *unstructured.Unstructured) ([]string, error),
@@ -292,6 +310,7 @@ func RunControllerWithConfig(vpcfg VolumePopulatorConfig) {
 		referenceGrantSynced:   referenceGrants.Informer().HasSynced,
 		podConfig:              vpcfg.PodConfig,
 		providerFunctionConfig: vpcfg.ProviderFunctionConfig,
+		mutatorConfig:          vpcfg.MutatorConfig,
 		crossNamespace:         vpcfg.CrossNamespace,
 		providerMetricManager:  vpcfg.ProviderMetricManager,
 	}
@@ -701,9 +720,24 @@ func (c *controller) syncPvc(ctx context.Context, key, pvcNamespace, pvcName str
 				annSelectedNode: nodeName,
 			}
 		}
+		if c.mutatorConfig != nil && c.mutatorConfig.PvcPrimeMutator != nil {
+			mp := PvcPrimeMutatorParams{
+				PvcPrime:     pvcPrime,
+				StorageClass: storageClass,
+			}
+			pvcPrime, err = c.mutatorConfig.PvcPrimeMutator(mp)
+			if err != nil {
+				c.recorder.Eventf(pvc, corev1.EventTypeWarning, reasonPVCPrimeMutatorError, "Failed to mutate populator pvcPrime: %s", err)
+				return err
+			}
+			if pvcPrime == nil {
+				c.recorder.Eventf(pvc, corev1.EventTypeWarning, reasonPVCPrimeMutatorError, "pvcPrime must not be nil")
+				return fmt.Errorf("pvcPrime must not be nil")
+			}
+		}
 		pvcPrime, err = c.kubeClient.CoreV1().PersistentVolumeClaims(c.populatorNamespace).Create(ctx, pvcPrime, metav1.CreateOptions{})
 		if err != nil {
-			c.recorder.Eventf(pvc, corev1.EventTypeWarning, reasonPVCCreationError, "Failed to create populator PVC prime: %s", err)
+			c.recorder.Eventf(pvc, corev1.EventTypeWarning, reasonPVCPrimeCreationError, "Failed to create populator pvcPrime: %s", err)
 			return err
 		}
 	}
@@ -734,7 +768,7 @@ func (c *controller) syncPvc(ctx context.Context, key, pvcNamespace, pvcName str
 			if c.providerFunctionConfig.PopulateFn != nil {
 
 				if "" == pvcPrime.Spec.VolumeName {
-					// We'll get called again later when the pvc prime gets bounded
+					// We'll get called again later when the pvcPrime gets bounded
 					return nil
 				}
 				pv, err := params.KubeClient.CoreV1().PersistentVolumes().Get(ctx, pvcPrime.Spec.VolumeName, metav1.GetOptions{})