✨ Make the anonymous field of the groupName marker optional

pkg/crd/markers/package.go

@@ -22,7 +22,7 @@ import (
 
 func init() {
 	AllDefinitions = append(AllDefinitions,
-		must(markers.MakeDefinition("groupName", markers.DescribesPackage, "")).
+		mustOptional(markers.MakeDefinition("groupName", markers.DescribesPackage, "")).
 			WithHelp(markers.SimpleHelp("CRD", "specifies the API group name for this package.")),
 
 		must(markers.MakeDefinition("versionName", markers.DescribesPackage, "")).

pkg/crd/markers/register.go

@@ -17,6 +17,7 @@ limitations under the License.
 package markers
 
 import (
+	"fmt"
 	"reflect"
 
 	"sigs.k8s.io/controller-tools/pkg/markers"
@@ -56,6 +57,19 @@ func must(def *markers.Definition, err error) *definitionWithHelp {
 	}
 }
 
+func mustOptional(def *markers.Definition, err error) *definitionWithHelp {
+	def = markers.Must(def, err)
+	if !def.AnonymousField() {
+		def = markers.Must(def, fmt.Errorf("not an anonymous field: %v", def))
+	}
+	field := def.Fields[""]
+	field.Optional = true
+	def.Fields[""] = field
+	return &definitionWithHelp{
+		Definition: def,
+	}
+}
+
 // AllDefinitions contains all marker definitions for this package.
 var AllDefinitions []*definitionWithHelp
 

pkg/crd/parser_integration_test.go

@@ -100,9 +100,9 @@ var _ = Describe("CRD Generation From Parsing to CustomResourceDefinition", func
 			}
 		})
 
-		assertCRD := func(pkg *loader.Package, kind, fileName string) {
-			By(fmt.Sprintf("requesting that the %s CRD be generated", kind))
-			groupKind := schema.GroupKind{Kind: kind, Group: "testdata.kubebuilder.io"}
+		assertCRDForGroupKind := func(pkg *loader.Package, groupKind schema.GroupKind, fileName string) {
+			kind := groupKind.Kind
+			By(fmt.Sprintf("requesting that the %s CRD be generated in group %s", kind, groupKind.Group))
 			parser.NeedCRDFor(groupKind, nil)
 
 			By(fmt.Sprintf("fixing top level ObjectMeta on the %s CRD", kind))
@@ -131,6 +131,10 @@ var _ = Describe("CRD Generation From Parsing to CustomResourceDefinition", func
 			ExpectWithOffset(1, parser.CustomResourceDefinitions[groupKind]).To(Equal(crd), "type not as expected, check pkg/crd/testdata/README.md for more details.\n\nDiff:\n\n%s", cmp.Diff(parser.CustomResourceDefinitions[groupKind], crd))
 		}
 
+		assertCRD := func(pkg *loader.Package, kind, fileName string) {
+			assertCRDForGroupKind(pkg, schema.GroupKind{Group: "testdata.kubebuilder.io", Kind: kind}, fileName)
+		}
+
 		assertError := func(pkg *loader.Package, kind, errorMsg string) {
 			By(fmt.Sprintf("requesting that the %s CRD be generated", kind))
 			groupKind := schema.GroupKind{Kind: kind, Group: "testdata.kubebuilder.io"}
@@ -183,6 +187,16 @@ var _ = Describe("CRD Generation From Parsing to CustomResourceDefinition", func
 				assertError(pkgs[0], "CronJob", "is not in 'xxx=xxx' format")
 			})
 		})
+
+		Context("CronJob API without group", func() {
+			BeforeEach(func() {
+				pkgPaths = []string{"./nogroup"}
+				expPkgLen = 1
+			})
+			It("should successfully generate the CronJob CRD", func() {
+				assertCRDForGroupKind(pkgs[0], schema.GroupKind{Kind: "CronJob"}, "testdata._cronjobs.yaml")
+			})
+		})
 	})
 
 	It("should generate plural words for Kind correctly", func() {

pkg/crd/testdata/nogroup/types.go

@@ -0,0 +1,29 @@
+/*
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// +groupName=
+package nogroup
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// +kubebuilder:object:root=true
+
+// CronJob is the Schema for the cronjobs API
+type CronJob struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+}

pkg/crd/testdata/testdata._cronjobs.yaml

@@ -0,0 +1,41 @@
+---
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: (devel)
+  name: cronjobs.
+spec:
+  group: ""
+  names:
+    kind: CronJob
+    listKind: CronJobList
+    plural: cronjobs
+    singular: cronjob
+  scope: Namespaced
+  versions:
+  - name: nogroup
+    schema:
+      openAPIV3Schema:
+        description: CronJob is the Schema for the cronjobs API
+        properties:
+          apiVersion:
+            description: |-
+              APIVersion defines the versioned schema of this representation of an object.
+              Servers should convert recognized schemas to the latest internal value, and
+              may reject unrecognized values.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
+            type: string
+          kind:
+            description: |-
+              Kind is a string value representing the REST resource this object represents.
+              Servers may infer this from the endpoint the client submits requests to.
+              Cannot be updated.
+              In CamelCase.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
+            type: string
+          metadata:
+            type: object
+        type: object
+    served: true
+    storage: true