crd: prohibit preserveUnknownFields=true

pkg/crd/gen.go

@@ -107,14 +107,12 @@ func transformRemoveCRDStatus(obj map[string]interface{}) error {
 	return nil
 }
 
-// transformPreserveUnknownFields adds spec.preserveUnknownFields=value.
-func transformPreserveUnknownFields(value bool) func(map[string]interface{}) error {
-	return func(obj map[string]interface{}) error {
-		if spec, ok := obj["spec"].(map[interface{}]interface{}); ok {
-			spec["preserveUnknownFields"] = value
-		}
-		return nil
+// transformPreserveUnknownFields adds spec.preserveUnknownFields=false.
+func transformPreserveUnknownFields(obj map[string]interface{}) error {
+	if spec, ok := obj["spec"].(map[interface{}]interface{}); ok {
+		spec["preserveUnknownFields"] = false
 	}
+	return nil
 }
 
 func (g Generator) Generate(ctx *genall.GenerationContext) error {
@@ -168,7 +166,10 @@ func (g Generator) Generate(ctx *genall.GenerationContext) error {
 		genall.WithTransform(genall.TransformRemoveCreationTimestamp),
 	}
 	if g.PreserveUnknownFields != nil {
-		yamlOpts = append(yamlOpts, genall.WithTransform(transformPreserveUnknownFields(*g.PreserveUnknownFields)))
+		if *g.PreserveUnknownFields {
+			return fmt.Errorf("preserveUnknownFields must be false")
+		}
+		yamlOpts = append(yamlOpts, genall.WithTransform(transformPreserveUnknownFields))
 	}
 
 	for _, groupKind := range kubeKinds {

pkg/crd/gen_integration_test.go

@@ -133,17 +133,14 @@ var _ = Describe("CRD Generation proper defaulting", func() {
 		Expect(out.buf.String()).To(ContainSubstring("preserveUnknownFields: false"))
 	})
 
-	It("should add preserveUnknownFields=true when specified", func() {
+	It("should not add preserveUnknownFields=true when specified", func() {
 		By("calling Generate")
 		yes := true
 		gen := &crd.Generator{
 			CRDVersions:           []string{"v1"},
 			PreserveUnknownFields: &yes,
 		}
-		Expect(gen.Generate(ctx)).NotTo(HaveOccurred())
-
-		By("searching preserveUnknownFields")
-		Expect(out.buf.String()).To(ContainSubstring("preserveUnknownFields: true"))
+		Expect(gen.Generate(ctx)).To(MatchError("preserveUnknownFields must be false"))
 	})
 
 	It("should not add preserveUnknownFields when not specified", func() {