Add support for feature gates

go.mod

@@ -10,8 +10,10 @@ require (
 	github.com/stretchr/testify v1.9.0
 	k8s.io/api v0.29.4
 	k8s.io/apimachinery v0.29.4
+	k8s.io/apiserver v0.29.2
 	k8s.io/client-go v0.29.4
 	k8s.io/code-generator v0.29.4
+	k8s.io/component-base v0.29.2
 	k8s.io/klog v1.0.0
 	k8s.io/klog/v2 v2.110.1
 	k8s.io/kube-openapi v0.0.0-20231010175941-2dd684a91f00
@@ -22,6 +24,7 @@ require (
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/blang/semver/v4 v4.0.0 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/emicklei/go-restful/v3 v3.11.0 // indirect
@@ -75,7 +78,6 @@ require (
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/apiextensions-apiserver v0.29.2 // indirect
-	k8s.io/component-base v0.29.2 // indirect
 	k8s.io/gengo v0.0.0-20230829151522-9cce18d56c01 // indirect
 	sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd // indirect
 	sigs.k8s.io/yaml v1.4.0 // indirect

go.sum

@@ -1,5 +1,7 @@
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/blang/semver/v4 v4.0.0 h1:1PFHFE6yCCTv8C1TeyNNarDzntLi7wMI5i/pzqYIsAM=
+github.com/blang/semver/v4 v4.0.0/go.mod h1:IbckMUScFkM3pff0VJDNKRiT6TG/YpiHIM2yvyW5YoQ=
 github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
 github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
@@ -192,6 +194,8 @@ k8s.io/apiextensions-apiserver v0.29.2 h1:UK3xB5lOWSnhaCk0RFZ0LUacPZz9RY4wi/yt2I
 k8s.io/apiextensions-apiserver v0.29.2/go.mod h1:aLfYjpA5p3OwtqNXQFkhJ56TB+spV8Gc4wfMhUA3/b8=
 k8s.io/apimachinery v0.29.4 h1:RaFdJiDmuKs/8cm1M6Dh1Kvyh59YQFDcFuFTSmXes6Q=
 k8s.io/apimachinery v0.29.4/go.mod h1:i3FJVwhvSp/6n8Fl4K97PJEP8C+MM+aoDq4+ZJBf70Y=
+k8s.io/apiserver v0.29.2 h1:+Z9S0dSNr+CjnVXQePG8TcBWHr3Q7BmAr7NraHvsMiQ=
+k8s.io/apiserver v0.29.2/go.mod h1:B0LieKVoyU7ykQvPFm7XSdIHaCHSzCzQWPFa5bqbeMQ=
 k8s.io/client-go v0.29.4 h1:79ytIedxVfyXV8rpH3jCBW0u+un0fxHDwX5F9K8dPR8=
 k8s.io/client-go v0.29.4/go.mod h1:kC1thZQ4zQWYwldsfI088BbK6RkxK+aF5ebV8y9Q4tk=
 k8s.io/code-generator v0.29.4 h1:8ESudFNbY5/9BzB8KOEFG2uV9Q0AQxkc4mrQESr30Ks=

main.go

@@ -26,6 +26,7 @@ import (
 
 	"k8s.io/apimachinery/pkg/runtime"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
@@ -58,13 +59,16 @@ func main() {
 	var probeAddr string
 	var qps float64
 	var burst int
+	var featureGates string
 	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+
 			"Enabling this will ensure there is only one active controller manager.")
 	flag.Float64Var(&qps, "kube-api-qps", 500, "Maximum QPS to use while talking with Kubernetes API")
 	flag.IntVar(&burst, "kube-api-burst", 500, "Maximum burst for throttle while talking with Kubernetes API")
+	flag.StringVar(&featureGates, "feature-gates", "", "A set of key=value pairs that describe feature gates for alpha/experimental features.")
+
 	opts := zap.Options{
 		Development: true,
 	}
@@ -77,6 +81,11 @@ func main() {
 	kubeConfig.QPS = float32(qps)
 	kubeConfig.Burst = burst
 
+	if err := utilfeature.DefaultMutableFeatureGate.Set(featureGates); err != nil {
+		setupLog.Error(err, "Unable to set flag gates for known features")
+		os.Exit(1)
+	}
+
 	mgr, err := ctrl.NewManager(kubeConfig, ctrl.Options{
 		Scheme: scheme,
 		Metrics: server.Options{

pkg/features/features.go

@@ -0,0 +1,68 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+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.
+*/
+
+package features
+
+import (
+	"fmt"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/util/runtime"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	"k8s.io/component-base/featuregate"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
+)
+
+const (
+// Example
+// owner: <feature owner>
+// kep: <KEP link>
+// alpha: v0.5
+// beta: v0.6
+//
+// Enables example.
+// Example featuregate.Feature = "Example"
+)
+
+func init() {
+	runtime.Must(utilfeature.DefaultMutableFeatureGate.Add(defaultFeatureGates))
+}
+
+// defaultFeatureGates consists of all known Jobset-specific feature keys.
+// To add a new feature, define a key for it above and add it here. The features will be
+// available throughout Jobset binaries.
+//
+// Entries are separated from each other with blank lines to avoid sweeping gofmt changes
+// when adding or removing one entry.
+var defaultFeatureGates = map[featuregate.Feature]featuregate.FeatureSpec{
+	// Example: {Default: true, PreRelease: featuregate.Beta},
+}
+
+func SetFeatureGateDuringTest(tb testing.TB, f featuregate.Feature, value bool) func() {
+	return featuregatetesting.SetFeatureGateDuringTest(tb, utilfeature.DefaultFeatureGate, f, value)
+}
+
+// Enabled is helper for `utilfeature.DefaultFeatureGate.Enabled()`
+func Enabled(f featuregate.Feature) bool {
+	return utilfeature.DefaultFeatureGate.Enabled(f)
+}
+
+// SetEnable helper function that can be used to set the enabled value of a feature gate,
+// it should only be used in integration test pending the merge of
+// https://github.com/kubernetes/kubernetes/pull/118346
+func SetEnable(f featuregate.Feature, v bool) error {
+	return utilfeature.DefaultMutableFeatureGate.Set(fmt.Sprintf("%s=%v", f, v))
+}