From b8470917f1fc1bab4a79c8c914819dda6264bf98 Mon Sep 17 00:00:00 2001
From: Cookie Wang <luckymrwang@163.com>
Date: Sun, 16 Apr 2023 22:15:18 +0800
Subject: [PATCH] feat: add feature gate

---
 cmd/agent/app/start.go   |  2 ++
 go.mod                   |  2 +-
 pkg/features/features.go | 51 ++++++++++++++++++++++++++++++++++++++++
 raven.sh                 |  2 +-
 4 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 pkg/features/features.go

diff --git a/cmd/agent/app/start.go b/cmd/agent/app/start.go
index 6d7636b..59343c5 100644
--- a/cmd/agent/app/start.go
+++ b/cmd/agent/app/start.go
@@ -25,6 +25,7 @@ import (
 
 	"github.com/openyurtio/raven/cmd/agent/app/config"
 	"github.com/openyurtio/raven/cmd/agent/app/options"
+	"github.com/openyurtio/raven/pkg/features"
 	"github.com/openyurtio/raven/pkg/k8s"
 	"github.com/openyurtio/raven/pkg/networkengine/routedriver"
 	"github.com/openyurtio/raven/pkg/networkengine/vpndriver"
@@ -52,6 +53,7 @@ func NewRavenAgentCommand(ctx context.Context) *cobra.Command {
 	}
 
 	agentOptions.AddFlags(cmd.Flags())
+	features.DefaultMutableFeatureGate.AddFlag(cmd.Flags())
 	return cmd
 }
 
diff --git a/go.mod b/go.mod
index b57fd9b..2c0db66 100644
--- a/go.mod
+++ b/go.mod
@@ -15,6 +15,7 @@ require (
 	k8s.io/apimachinery v0.23.2
 	k8s.io/apiserver v0.23.2
 	k8s.io/client-go v0.23.2
+	k8s.io/component-base v0.23.2
 	k8s.io/klog/v2 v2.30.0
 	sigs.k8s.io/controller-runtime v0.11.0
 )
@@ -102,7 +103,6 @@ require (
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/api v0.23.2 // indirect
 	k8s.io/apiextensions-apiserver v0.23.0 // indirect
-	k8s.io/component-base v0.23.2 // indirect
 	k8s.io/kube-openapi v0.0.0-20211115234752-e816edb12b65 // indirect
 	k8s.io/utils v0.0.0-20210930125809-cb0fa318a74b // indirect
 	sigs.k8s.io/apiserver-network-proxy/konnectivity-client v0.0.27 // indirect
diff --git a/pkg/features/features.go b/pkg/features/features.go
new file mode 100644
index 0000000..49ab311
--- /dev/null
+++ b/pkg/features/features.go
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2022 The OpenYurt 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 (
+	"k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/component-base/featuregate"
+)
+
+var (
+	// DefaultMutableFeatureGate is a mutable version of DefaultFeatureGate.
+	DefaultMutableFeatureGate featuregate.MutableFeatureGate = featuregate.NewFeatureGate()
+
+	// DefaultFeatureGate is a shared global FeatureGate.
+	// Top-level commands/options setup that needs to modify this feature gate should use DefaultMutableFeatureGate.
+	DefaultFeatureGate featuregate.FeatureGate = DefaultMutableFeatureGate
+)
+
+func init() {
+	runtime.Must(DefaultMutableFeatureGate.Add(defaultRavenFeatureGates))
+}
+
+const (
+	// RavenL7Proxy setups and serves a L7 proxy.
+	//
+	// owner: @luckymrwang
+	// alpha: v0.3.1
+	// Setting on openyurt and raven-agent side.
+	RavenL7Proxy featuregate.Feature = "RavenL7Proxy"
+)
+
+// defaultRavenFeatureGates consists of all known Kubernetes-specific and raven feature keys.
+// To add a new feature, define a key for it above and add it here. The features will be
+// available throughout raven binaries.
+var defaultRavenFeatureGates = map[featuregate.Feature]featuregate.FeatureSpec{
+	RavenL7Proxy: {Default: false, PreRelease: featuregate.Alpha, LockToDefault: false},
+}
diff --git a/raven.sh b/raven.sh
index 4704b1f..bd97a3d 100755
--- a/raven.sh
+++ b/raven.sh
@@ -21,4 +21,4 @@ set -e -x
 [ "$(cat /proc/sys/net/ipv4/conf/all/send_redirects)" = 0 ] || echo 0 > /proc/sys/net/ipv4/conf/all/send_redirects
 
 # run raven agent
-exec agent --node-name="$NODE_NAME" --vpn-driver="$VPN_DRIVER" --forward-node-ip="$FORWARD_NODE_IP" --metric-bind-addr="$METRIC_BIND_ADDR"
\ No newline at end of file
+exec agent --node-name="$NODE_NAME" --vpn-driver="$VPN_DRIVER" --forward-node-ip="$FORWARD_NODE_IP" --metric-bind-addr="$METRIC_BIND_ADDR" --feature-gates="$FEATURE_GATES"
\ No newline at end of file