feat: Support MutatingWebhookConfiguration & ValidatingWebhookConfigu…

…ration relationships

Signed-off-by: Justin Toh <tohjustin@hotmail.com>

README.md

@@ -35,6 +35,7 @@ List of supported relationships used for discovering dependent objects:
   - [Controller References](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/api-machinery/controller-ref.md) & [Owner References](https://kubernetes.io/docs/concepts/overview/working-with-objects/owners-dependents/)
   - [Event References](https://kubernetes.io/docs/reference/kubernetes-api/cluster-resources/event-v1/)
   - [Ingress References](https://kubernetes.io/docs/reference/kubernetes-api/service-resources/ingress-v1/) & [IngressClass Reference](https://kubernetes.io/docs/reference/kubernetes-api/service-resources/ingress-class-v1/)
+  - [MutatingWebhookConfiguration References](https://kubernetes.io/docs/reference/kubernetes-api/extend-resources/mutating-webhook-configuration-v1/) & [ValidatingWebhookConfiguration References](https://kubernetes.io/docs/reference/kubernetes-api/extend-resources/validating-webhook-configuration-v1/)
   - [PersistentVolume References](https://kubernetes.io/docs/reference/kubernetes-api/config-and-storage-resources/persistent-volume-v1/) & [PersistentVolumeClaim References](https://kubernetes.io/docs/reference/kubernetes-api/config-and-storage-resources/persistent-volume-claim-v1/)
   - [Pod References](https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/)
   - [Service References](https://kubernetes.io/docs/reference/kubernetes-api/service-resources/service-v1/)

pkg/cmd/lineage/graph.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"sort"
 
+	admissionregistrationv1 "k8s.io/api/admissionregistration/v1"
 	corev1 "k8s.io/api/core/v1"
 	extensionsv1beta1 "k8s.io/api/extensions/v1beta1"
 	networkingv1 "k8s.io/api/networking/v1"
@@ -195,6 +196,9 @@ const (
 	RelationshipIngressService         Relationship = "IngressService"
 	RelationshipIngressTLSSecret       Relationship = "IngressTLSSecret"
 
+	// Kubernetes MutatingWebhookConfiguration & ValidatingWebhookConfiguration relationships.
+	RelationshipWebhookConfigurationService Relationship = "WebhookConfigurationService"
+
 	// Kubernetes Owner-Dependent relationships.
 	RelationshipControllerRef Relationship = "ControllerReference"
 	RelationshipOwnerRef      Relationship = "OwnerReference"
@@ -372,6 +376,20 @@ func resolveDependents(objects []unstructuredv1.Unstructured, rootUID types.UID)
 				klog.V(4).Infof("Failed to get relationships for serviceaccount named \"%s\" in namespace \"%s\": %s", node.Name, node.Namespace, err)
 				continue
 			}
+		// Populate dependents based on MutatingWebhookConfiguration relationships
+		case node.Group == "admissionregistration.k8s.io" && node.Kind == "MutatingWebhookConfiguration":
+			rmap, err = getMutatingWebhookConfigurationRelationships(node)
+			if err != nil {
+				klog.V(4).Infof("Failed to get relationships for mutatingwebhookconfiguration named \"%s\": %s", node.Name, err)
+				continue
+			}
+		// Populate dependents based on ValidatingWebhookConfiguration relationships
+		case node.Group == "admissionregistration.k8s.io" && node.Kind == "ValidatingWebhookConfiguration":
+			rmap, err = getValidatingWebhookConfigurationRelationships(node)
+			if err != nil {
+				klog.V(4).Infof("Failed to get relationships for validatingwebhookconfiguration named \"%s\": %s", node.Name, err)
+				continue
+			}
 		// Populate dependents based on Event relationships
 		// TODO: It's possible to have events to be in a different namespace from the
 		//       its referenced object, so update the resource fetching logic to
@@ -594,6 +612,30 @@ func getIngressClassRelationships(n *Node) (*RelationshipMap, error) {
 	return &result, nil
 }
 
+// getMutatingWebhookConfigurationRelationships returns a map of relationships
+// that this MutatingWebhookConfiguration has with other objects, based on what
+// was referenced in its manifest.
+func getMutatingWebhookConfigurationRelationships(n *Node) (*RelationshipMap, error) {
+	var mwc admissionregistrationv1.MutatingWebhookConfiguration
+	err := runtime.DefaultUnstructuredConverter.FromUnstructured(n.UnstructuredContent(), &mwc)
+	if err != nil {
+		return nil, err
+	}
+
+	var ref ObjectReference
+	result := newRelationshipMap()
+
+	// RelationshipWebhookConfigurationService
+	for _, wh := range mwc.Webhooks {
+		if svc := wh.ClientConfig.Service; svc != nil {
+			ref = ObjectReference{Kind: "Service", Namespace: svc.Namespace, Name: svc.Name}
+			result.AddDependencyByKey(ref.Key(), RelationshipWebhookConfigurationService)
+		}
+	}
+
+	return &result, nil
+}
+
 // getPersistentVolumeRelationships returns a map of relationships that this
 // PersistentVolume has with other objects, based on what was referenced in its
 // manifest.
@@ -789,3 +831,27 @@ func getServiceAccountRelationships(n *Node) (*RelationshipMap, error) {
 
 	return &result, nil
 }
+
+// getValidatingWebhookConfigurationRelationships returns a map of relationships
+// that this ValidatingWebhookConfiguration has with other objects, based on
+// what was referenced in its manifest.
+func getValidatingWebhookConfigurationRelationships(n *Node) (*RelationshipMap, error) {
+	var vwc admissionregistrationv1.ValidatingWebhookConfiguration
+	err := runtime.DefaultUnstructuredConverter.FromUnstructured(n.UnstructuredContent(), &vwc)
+	if err != nil {
+		return nil, err
+	}
+
+	var ref ObjectReference
+	result := newRelationshipMap()
+
+	// RelationshipWebhookConfigurationService
+	for _, wh := range vwc.Webhooks {
+		if svc := wh.ClientConfig.Service; svc != nil {
+			ref = ObjectReference{Kind: "Service", Namespace: svc.Namespace, Name: svc.Name}
+			result.AddDependencyByKey(ref.Key(), RelationshipWebhookConfigurationService)
+		}
+	}
+
+	return &result, nil
+}