refactor(*): move getKubeClient to utils/kubernetes

cluster-autoscaler/config/autoscaling_options.go

@@ -221,8 +221,12 @@ type AutoscalingOptions struct {
 	AWSUseStaticInstanceList bool
 	// GCEOptions contain autoscaling options specific to GCE cloud provider.
 	GCEOptions GCEOptions
+	// Kubernetes master location.
+	Kubernetes string
 	// Path to kube configuration if available
 	KubeConfigPath string
+	// Content type of requests sent to APIServer.
+	KubeAPIContentType string
 	// Burst setting for kubernetes client
 	KubeClientBurst int
 	// QPS setting for kubernetes client

cluster-autoscaler/main.go

@@ -21,7 +21,6 @@ import (
 	"flag"
 	"fmt"
 	"net/http"
-	"net/url"
 	"os"
 	"os/signal"
 	"strconv"
@@ -63,7 +62,6 @@ import (
 	"k8s.io/client-go/informers"
 	kube_client "k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
-	"k8s.io/client-go/tools/clientcmd"
 	"k8s.io/client-go/tools/leaderelection"
 	"k8s.io/client-go/tools/leaderelection/resourcelock"
 	kube_flag "k8s.io/component-base/cli/flag"
@@ -353,7 +351,9 @@ func createAutoscalingOptions() config.AutoscalingOptions {
 		StatusTaints:                     *statusTaintsFlag,
 		BalancingExtraIgnoredLabels:      *balancingIgnoreLabelsFlag,
 		BalancingLabels:                  *balancingLabelsFlag,
+		Kubernetes:                       *kubernetes,
 		KubeConfigPath:                   *kubeConfigFile,
+		KubeAPIContentType:               *kubeAPIContentType,
 		KubeClientBurst:                  *kubeClientBurst,
 		KubeClientQPS:                    *kubeClientQPS,
 		NodeDeletionDelayTimeout:         *nodeDeletionDelayTimeout,
@@ -393,31 +393,6 @@ func createAutoscalingOptions() config.AutoscalingOptions {
 	}
 }
 
-func getKubeConfig() *rest.Config {
-	if *kubeConfigFile != "" {
-		klog.V(1).Infof("Using kubeconfig file: %s", *kubeConfigFile)
-		// use the current context in kubeconfig
-		config, err := clientcmd.BuildConfigFromFlags("", *kubeConfigFile)
-		if err != nil {
-			klog.Fatalf("Failed to build config: %v", err)
-		}
-		return config
-	}
-	url, err := url.Parse(*kubernetes)
-	if err != nil {
-		klog.Fatalf("Failed to parse Kubernetes url: %v", err)
-	}
-
-	kubeConfig, err := config.GetKubeClientConfig(url)
-	if err != nil {
-		klog.Fatalf("Failed to build Kubernetes client configuration: %v", err)
-	}
-
-	kubeConfig.ContentType = *kubeAPIContentType
-
-	return kubeConfig
-}
-
 func createKubeClient(kubeConfig *rest.Config) kube_client.Interface {
 	return kube_client.NewForConfigOrDie(kubeConfig)
 }
@@ -441,7 +416,7 @@ func buildAutoscaler(debuggingSnapshotter debuggingsnapshot.DebuggingSnapshotter
 	// Create basic config from flags.
 	autoscalingOptions := createAutoscalingOptions()
 
-	kubeClientConfig := getKubeConfig()
+	kubeClientConfig := kube_util.GetKubeConfig(autoscalingOptions)
 	kubeClientConfig.Burst = autoscalingOptions.KubeClientBurst
 	kubeClientConfig.QPS = float32(autoscalingOptions.KubeClientQPS)
 	kubeClient := createKubeClient(kubeClientConfig)
@@ -455,7 +430,7 @@ func buildAutoscaler(debuggingSnapshotter debuggingsnapshot.DebuggingSnapshotter
 	}
 	informerFactory := informers.NewSharedInformerFactoryWithOptions(kubeClient, 0, informers.WithTransform(trim))
 
-	eventsKubeClient := createKubeClient(getKubeConfig())
+	eventsKubeClient := createKubeClient(kube_util.GetKubeConfig(autoscalingOptions))
 
 	predicateChecker, err := predicatechecker.NewSchedulerBasedPredicateChecker(informerFactory, autoscalingOptions.SchedulerConfig)
 	if err != nil {
@@ -624,7 +599,7 @@ func main() {
 			klog.Fatalf("Unable to get hostname: %v", err)
 		}
 
-		kubeClient := createKubeClient(getKubeConfig())
+		kubeClient := createKubeClient(kube_util.GetKubeConfig(createAutoscalingOptions()))
 
 		// Validate that the client is ok.
 		_, err = kubeClient.CoreV1().Nodes().List(ctx.TODO(), metav1.ListOptions{})

cluster-autoscaler/utils/kubernetes/client.go

@@ -0,0 +1,56 @@
+/*
+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 kubernetes
+
+import (
+	"net/url"
+
+	"k8s.io/autoscaler/cluster-autoscaler/config"
+
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+	"k8s.io/klog/v2"
+)
+
+// GetKubeConfig returns the rest config from AutoscalingOptions.
+func GetKubeConfig(opts config.AutoscalingOptions) *rest.Config {
+	var kubeConfig *rest.Config
+	var err error
+
+	if opts.KubeConfigPath != "" {
+		klog.V(1).Infof("Using kubeconfig file: %s", opts.KubeConfigPath)
+		// use the current context in kubeconfig
+		kubeConfig, err = clientcmd.BuildConfigFromFlags("", opts.KubeConfigPath)
+		if err != nil {
+			klog.Fatalf("Failed to build config: %v", err)
+		}
+	} else {
+		url, err := url.Parse(opts.Kubernetes)
+		if err != nil {
+			klog.Fatalf("Failed to parse Kubernetes url: %v", err)
+		}
+
+		kubeConfig, err = config.GetKubeClientConfig(url)
+		if err != nil {
+			klog.Fatalf("Failed to build Kubernetes client configuration: %v", err)
+		}
+	}
+
+	kubeConfig.ContentType = opts.KubeAPIContentType
+
+	return kubeConfig
+}