dry-run: Create feature-gate flag

pkg/features/kube_features.go

@@ -409,6 +409,7 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	genericfeatures.APIResponseCompression:  {Default: false, PreRelease: utilfeature.Alpha},
 	genericfeatures.Initializers:            {Default: false, PreRelease: utilfeature.Alpha},
 	genericfeatures.APIListChunking:         {Default: true, PreRelease: utilfeature.Beta},
+	genericfeatures.DryRun:                  {Default: false, PreRelease: utilfeature.Alpha},
 
 	// inherited features from apiextensions-apiserver, relisted here to get a conflict if it is changed
 	// unintentionally on either side:

staging/src/k8s.io/apiserver/pkg/features/kube_features.go

@@ -63,6 +63,14 @@ const (
 	// Allow API clients to retrieve resource lists in chunks rather than
 	// all at once.
 	APIListChunking utilfeature.Feature = "APIListChunking"
+
+	// owner: @apelisse
+	// alpha: v1.12
+	//
+	// Allow requests to be processed but not stored, so that
+	// validation, merging, mutation can be tested without
+	// committing.
+	DryRun utilfeature.Feature = "DryRun"
 )
 
 func init() {
@@ -78,4 +86,5 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	APIResponseCompression:  {Default: false, PreRelease: utilfeature.Alpha},
 	Initializers:            {Default: false, PreRelease: utilfeature.Alpha},
 	APIListChunking:         {Default: true, PreRelease: utilfeature.Beta},
+	DryRun:                  {Default: false, PreRelease: utilfeature.Alpha},
 }