feat: Support CSINode relationships

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

README.md

@@ -88,6 +88,7 @@ List of supported relationships used for discovering dependent objects:
 - Kubernetes
   - [ClusterRole References](https://kubernetes.io/docs/reference/kubernetes-api/authorization-resources/cluster-role-v1/), [ClusterRoleBinding References](https://kubernetes.io/docs/reference/kubernetes-api/authorization-resources/cluster-role-binding-v1/) & [RoleBinding References](https://kubernetes.io/docs/reference/kubernetes-api/authorization-resources/role-binding-v1/)
   - [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/)
+  - [CSINode References](https://kubernetes.io/docs/reference/kubernetes-api/config-and-storage-resources/csi-node-v1/)
   - [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/)

internal/graph/graph.go

@@ -443,6 +443,13 @@ func ResolveDependents(m meta.RESTMapper, objects []unstructuredv1.Unstructured,
 				klog.V(4).Infof("Failed to get relationships for rolebinding named \"%s\" in namespace \"%s\": %s: %s", node.Name, node.Namespace, err)
 				continue
 			}
+		// Populate dependents based on CSINode relationships
+		case node.Group == "storage.k8s.io" && node.Kind == "CSINode":
+			rmap, err = getCSINodeRelationships(node)
+			if err != nil {
+				klog.V(4).Infof("Failed to get relationships for csinode named \"%s\": %s: %s", node.Name, err)
+				continue
+			}
 		default:
 			continue
 		}

internal/graph/kubernetes.go

@@ -6,6 +6,7 @@ import (
 	extensionsv1beta1 "k8s.io/api/extensions/v1beta1"
 	networkingv1 "k8s.io/api/networking/v1"
 	rbacv1 "k8s.io/api/rbac/v1"
+	storagev1 "k8s.io/api/storage/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -20,6 +21,9 @@ const (
 	RelationshipRoleBindingSubject         Relationship = "RoleBindingSubject"
 	RelationshipRoleBindingRole            Relationship = "RoleBindingRole"
 
+	// Kubernetes CSINode relationships.
+	RelationshipCSINodeDriver Relationship = "CSINodeDriver"
+
 	// Kubernetes Event relationships.
 	RelationshipEventRegarding Relationship = "EventRegarding"
 	RelationshipEventRelated   Relationship = "EventRelated"
@@ -114,6 +118,27 @@ func getClusterRoleBindingRelationships(n *Node) (*RelationshipMap, error) {
 	return &result, nil
 }
 
+// getCSINodeRelationships returns a map of relationships that this CSINode has
+// with other objects, based on what was referenced in its manifest.
+func getCSINodeRelationships(n *Node) (*RelationshipMap, error) {
+	var csin storagev1.CSINode
+	err := runtime.DefaultUnstructuredConverter.FromUnstructured(n.UnstructuredContent(), &csin)
+	if err != nil {
+		return nil, err
+	}
+
+	var ref ObjectReference
+	result := newRelationshipMap()
+
+	// RelationshipCSINodeDriver
+	for _, d := range csin.Spec.Drivers {
+		ref = ObjectReference{Group: "storage.k8s.io", Kind: "CSIDriver", Name: d.Name}
+		result.AddDependentByKey(ref.Key(), RelationshipCSINodeDriver)
+	}
+
+	return &result, nil
+}
+
 // getEventRelationships returns a map of relationships that this Event has with
 // other objects, based on what was referenced in its manifest.
 //nolint:unparam