pkg/flag: make feature gate extensible and split between generic and kube

pkg/features/kube_features.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2017 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 (
+	genericfeatures "k8s.io/apiserver/pkg/features"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+)
+
+const (
+	// Every feature gate should add method here following this template:
+	//
+	// // owner: @username
+	// // alpha: v1.4
+	// MyFeature() bool
+
+	// owner: @timstclair
+	// beta: v1.4
+	AppArmor utilfeature.Feature = "AppArmor"
+
+	// owner: @girishkalele
+	// alpha: v1.4
+	ExternalTrafficLocalOnly utilfeature.Feature = "AllowExtTrafficLocalEndpoints"
+
+	// owner: @saad-ali
+	// alpha: v1.3
+	DynamicVolumeProvisioning utilfeature.Feature = "DynamicVolumeProvisioning"
+
+	// owner: @mtaufen
+	// alpha: v1.4
+	DynamicKubeletConfig utilfeature.Feature = "DynamicKubeletConfig"
+
+	// owner: timstclair
+	// alpha: v1.5
+	//
+	// StreamingProxyRedirects controls whether the apiserver should intercept (and follow)
+	// redirects from the backend (Kubelet) for streaming requests (exec/attach/port-forward).
+	StreamingProxyRedirects utilfeature.Feature = genericfeatures.StreamingProxyRedirects
+
+	// owner: @pweil-
+	// alpha: v1.5
+	//
+	// Default userns=host for containers that are using other host namespaces, host mounts, the pod
+	// contains a privileged container, or specific non-namespaced capabilities (MKNOD, SYS_MODULE,
+	// SYS_TIME). This should only be enabled if user namespace remapping is enabled in the docker daemon.
+	ExperimentalHostUserNamespaceDefaultingGate utilfeature.Feature = "ExperimentalHostUserNamespaceDefaulting"
+)
+
+func init() {
+	utilfeature.DefaultFeatureGate.Add(defaultKubernetesFeatureGates)
+}
+
+// defaultKubernetesFeatureGates consists of all known Kubernetes-specific feature keys.
+// To add a new feature, define a key for it above and add it here. The features will be
+// available throughout Kubernetes binaries.
+var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureSpec{
+	ExternalTrafficLocalOnly:                    {Default: true, PreRelease: utilfeature.Beta},
+	AppArmor:                                    {Default: true, PreRelease: utilfeature.Beta},
+	DynamicKubeletConfig:                        {Default: false, PreRelease: utilfeature.Alpha},
+	DynamicVolumeProvisioning:                   {Default: true, PreRelease: utilfeature.Alpha},
+	ExperimentalHostUserNamespaceDefaultingGate: {Default: false, PreRelease: utilfeature.Beta},
+
+	// inherited features from generic apiserver, relisted here to get a conflict if it is changed
+	// unintentionally on either side:
+	StreamingProxyRedirects: {Default: true, PreRelease: utilfeature.Beta},
+}