Fix diff for CRD .spec.preserveUnknownFields

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Unreleased
 
 - Gracefully handle undefined resource schemes (https://github.com/pulumi/pulumi-kubernetes/pull/2504)
+- Fix diff for CRD .spec.preserveUnknownFields (https://github.com/pulumi/pulumi-kubernetes/pull/2506)
 
 ## 4.0.0 (July 19, 2023)
 

provider/pkg/clients/unstructured.go

@@ -65,6 +65,10 @@ func ToUnstructured(object metav1.Object) (*unstructured.Unstructured, error) {
 // This process normalizes semantically-equivalent resources into an identical output, which is important for diffing.
 // If the scheme is not defined, then return the original resource.
 func Normalize(uns *unstructured.Unstructured) (*unstructured.Unstructured, error) {
+	if IsCRD(uns) {
+		return normalizeCRD(uns), nil
+	}
+
 	obj, err := FromUnstructured(uns)
 	// Return the input resource rather than an error if this operation fails.
 	if err != nil {
@@ -73,6 +77,21 @@ func Normalize(uns *unstructured.Unstructured) (*unstructured.Unstructured, erro
 	return ToUnstructured(obj)
 }
 
+// normalizeCRD manually normalizes CRD resources, which require special handling due to the lack of defined conversion
+// scheme for CRDs.
+func normalizeCRD(uns *unstructured.Unstructured) *unstructured.Unstructured {
+	contract.Assertf(IsCRD(uns), "normalizeCRD called on a non-CRD resource: %s", uns.GetAPIVersion())
+
+	// .spec.preserveUnknownFields is deprecated, and will be removed by the apiserver on the created resource if the
+	// value is false. Normalize for diffing by removing this field if present and set to "false".
+	// See https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#field-pruning
+	preserve, found, err := unstructured.NestedBool(uns.Object, "spec", "preserveUnknownFields")
+	if err == nil && found && !preserve {
+		unstructured.RemoveNestedField(uns.Object, "spec", "preserveUnknownFields")
+	}
+	return uns
+}
+
 func PodFromUnstructured(uns *unstructured.Unstructured) (*corev1.Pod, error) {
 	const expectedAPIVersion = "v1"
 

provider/pkg/clients/unstructured_test.go

@@ -118,6 +118,95 @@ var (
 			},
 		},
 	}
+
+	crdPreserveUnknownFieldsUnstructured = &unstructured.Unstructured{
+		Object: map[string]any{
+			"apiVersion": "apiextensions.k8s.io/v1",
+			"kind":       "CustomResourceDefinition",
+			"metadata": map[string]any{
+				"name": "foobars.stable.example.com",
+			},
+			"spec": map[string]any{
+				"group": "stable.example.com",
+				"names": map[string]any{
+					"kind":   "FooBar",
+					"plural": "foobars",
+					"shortNames": []string{
+						"fb",
+					},
+					"singular": "foobar",
+				},
+				"preserveUnknownFields": false,
+				"scope":                 "Namespaced",
+				"versions": []map[string]any{
+					{
+						"name": "v1",
+						"schema": map[string]any{
+							"openAPIV3Schema": map[string]any{
+								"properties": map[string]any{
+									"spec": map[string]any{
+										"properties": map[string]any{
+											"foo": map[string]any{
+												"type": "string",
+											},
+										},
+										"type": "object",
+									},
+								},
+								"type": "object",
+							},
+						},
+						"served":  true,
+						"storage": true,
+					},
+				},
+			},
+		},
+	}
+
+	crdUnstructured = &unstructured.Unstructured{
+		Object: map[string]any{
+			"apiVersion": "apiextensions.k8s.io/v1",
+			"kind":       "CustomResourceDefinition",
+			"metadata": map[string]any{
+				"name": "foobars.stable.example.com",
+			},
+			"spec": map[string]any{
+				"group": "stable.example.com",
+				"names": map[string]any{
+					"kind":   "FooBar",
+					"plural": "foobars",
+					"shortNames": []string{
+						"fb",
+					},
+					"singular": "foobar",
+				},
+				"scope": "Namespaced",
+				"versions": []map[string]any{
+					{
+						"name": "v1",
+						"schema": map[string]any{
+							"openAPIV3Schema": map[string]any{
+								"properties": map[string]any{
+									"spec": map[string]any{
+										"properties": map[string]any{
+											"foo": map[string]any{
+												"type": "string",
+											},
+										},
+										"type": "object",
+									},
+								},
+								"type": "object",
+							},
+						},
+						"served":  true,
+						"storage": true,
+					},
+				},
+			},
+		},
+	}
 )
 
 func TestFromUnstructured(t *testing.T) {
@@ -159,6 +248,7 @@ func TestNormalize(t *testing.T) {
 		wantErr bool
 	}{
 		{"unregistered GVK", args{uns: unregisteredGVK}, unregisteredGVK, false},
+		{"CRD with preserveUnknownFields", args{uns: crdPreserveUnknownFieldsUnstructured}, crdUnstructured, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

provider/pkg/provider/provider.go

@@ -2684,9 +2684,9 @@ func pruneLiveState(live, oldInputs *unstructured.Unstructured) *unstructured.Un
 	return oldLivePruned
 }
 
-// shouldNormalize returns false for CRDs and CustomResources, and true otherwise.
+// shouldNormalize returns false for CustomResources, and true otherwise.
 func shouldNormalize(uns *unstructured.Unstructured) bool {
-	return !clients.IsCRD(uns) && kinds.KnownGroupVersions.Has(uns.GetAPIVersion())
+	return kinds.KnownGroupVersions.Has(uns.GetAPIVersion())
 }
 
 // normalize converts an Unstructured resource into a normalized form so that semantically equivalent representations