✨ Make the anonymous value of the groupName marker optional

Upstream introduced the use of empty groupName markers in k/k PR 125162.
This breaks groupName parsing because its field is non-optional. Add an
additional mustOptional function that takes anonymous field definitions
and turns them into optional ones.

Signed-off-by: Tom Wieczorek <twieczorek@mirantis.com>

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