kube-proxy: internal config: add Windows section

Introduce Windows section for internal configuration of kube-proxy
adhering to the v1alpha2 version specifications as detailed in
https://kep.k8s.io/784. This also introduces WindowsRunAsService
to v1alpha1 configuration.

Signed-off-by: Daman Arora <[email protected]>

Author: aroradaman

cmd/kube-proxy/app/init_windows.go

@@ -37,7 +37,7 @@ func initForOS(windowsService bool) error {
 }
 
 func (o *Options) addOSFlags(fs *pflag.FlagSet) {
-	fs.BoolVar(&o.WindowsService, "windows-service", o.WindowsService, "Enable Windows Service Control Manager API integration")
+	fs.BoolVar(&o.config.Windows.RunAsService, "windows-service", o.config.Windows.RunAsService, "Enable Windows Service Control Manager API integration")
 	fs.StringVar(&o.config.Winkernel.SourceVip, "source-vip", o.config.Winkernel.SourceVip, "The IP address of the source VIP for non-DSR.")
 	fs.StringVar(&o.config.Winkernel.NetworkName, "network-name", o.config.Winkernel.NetworkName, "The name of the cluster network.")
 	fs.BoolVar(&o.config.Winkernel.EnableDSR, "enable-dsr", o.config.Winkernel.EnableDSR, "If true make kube-proxy apply DSR policies for service VIP")

cmd/kube-proxy/app/options.go

@@ -54,9 +54,6 @@ type Options struct {
 	CleanupAndExit bool
 	// InitAndExit, when true, makes the proxy server makes configurations that need privileged access, then exit.
 	InitAndExit bool
-	// WindowsService should be set to true if kube-proxy is running as a service on Windows.
-	// Its corresponding flag only gets registered in Windows builds
-	WindowsService bool
 	// config is the proxy server's configuration object.
 	config *kubeproxyconfig.KubeProxyConfiguration
 	// watcher is used to watch on the update change of ConfigFile

cmd/kube-proxy/app/server.go

@@ -104,7 +104,7 @@ with the apiserver API to configure the proxy.`,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			verflag.PrintAndExitIfRequested()
 
-			if err := initForOS(opts.WindowsService); err != nil {
+			if err := initForOS(opts.config.Windows.RunAsService); err != nil {
 				return fmt.Errorf("failed os init: %w", err)
 			}
 

pkg/generated/openapi/zz_generated.openapi.go

@@ -22,6 +22,13 @@ import (
 	logsapi "k8s.io/component-base/logs/api/v1"
 )
 
+// KubeProxyWindowsConfiguration contains Windows platform related configuration details for the
+// Kubernetes proxy server that aren't specific to a particular backend
+type KubeProxyWindowsConfiguration struct {
+	// runAsService, if true, enables Windows service control manager API integration.
+	RunAsService bool
+}
+
 // KubeProxyIPTablesConfiguration contains iptables-related configuration
 // details for the Kubernetes proxy server.
 type KubeProxyIPTablesConfiguration struct {
@@ -165,6 +172,9 @@ type DetectLocalConfiguration struct {
 type KubeProxyConfiguration struct {
 	metav1.TypeMeta
 
+	// windows contains Windows-related configuration options.
+	Windows KubeProxyWindowsConfiguration
+
 	// featureGates is a map of feature names to bools that enable or disable alpha/experimental features.
 	FeatureGates map[string]bool
 

pkg/proxy/apis/config/types.go

@@ -0,0 +1,41 @@
+/*
+Copyright 2024 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 v1alpha1
+
+import (
+	"k8s.io/apimachinery/pkg/conversion"
+	"k8s.io/kube-proxy/config/v1alpha1"
+	"k8s.io/kubernetes/pkg/proxy/apis/config"
+)
+
+// Convert_config_KubeProxyConfiguration_To_v1alpha1_KubeProxyConfiguration is defined here, because public conversion is not auto-generated due to existing warnings.
+func Convert_config_KubeProxyConfiguration_To_v1alpha1_KubeProxyConfiguration(in *config.KubeProxyConfiguration, out *v1alpha1.KubeProxyConfiguration, scope conversion.Scope) error {
+	if err := autoConvert_config_KubeProxyConfiguration_To_v1alpha1_KubeProxyConfiguration(in, out, scope); err != nil {
+		return err
+	}
+	out.WindowsRunAsService = in.Windows.RunAsService
+	return nil
+}
+
+// Convert_v1alpha1_KubeProxyConfiguration_To_config_KubeProxyConfiguration is defined here, because public conversion is not auto-generated due to existing warnings.
+func Convert_v1alpha1_KubeProxyConfiguration_To_config_KubeProxyConfiguration(in *v1alpha1.KubeProxyConfiguration, out *config.KubeProxyConfiguration, scope conversion.Scope) error {
+	if err := autoConvert_v1alpha1_KubeProxyConfiguration_To_config_KubeProxyConfiguration(in, out, scope); err != nil {
+		return err
+	}
+	out.Windows.RunAsService = in.WindowsRunAsService
+	return nil
+}

pkg/proxy/apis/config/v1alpha1/conversion.go

@@ -243,6 +243,9 @@ type KubeProxyConfiguration struct {
 
 	// portRange was previously used to configure the userspace proxy, but is now unused.
 	PortRange string `json:"portRange"`
+
+	// windowsRunAsService, if true, enables Windows service control manager API integration.
+	WindowsRunAsService bool `json:"windowsRunAsService,omitempty"`
 }
 
 // ProxyMode represents modes used by the Kubernetes proxy server.