optionally allow CLUSTER_ENDPOINT to be used rather than the cluster-…

…ip (#2138)

* optionally allow CLUSTER_ENDPOINT to be used rather than the kubernetes cluster ip

* remove check for kube-proxy

* add version to readme

README.md

@@ -410,6 +410,17 @@ Specifies the cluster name to tag allocated ENIs with. See the "Cluster Name tag
 
 ---
 
+#### `CLUSTER_ENDPOINT` (v1.12.1+)
+
+Type: String
+
+Default: `""`
+
+Specifies the cluster endpoint to use for connecting to the api-server without relying on kube-proxy. 
+This is an optional configuration parameter that can improve the initialization time of the AWS VPC CNI.
+
+---
+
 #### `ENABLE_POD_ENI` (v1.7.0+)
 
 Type: Boolean as a String

cmd/aws-k8s-agent/main.go

@@ -29,13 +29,13 @@ func main() {
 }
 
 func _main() int {
-	//Do not add anything before initializing logger
+	// Do not add anything before initializing logger
 	log := logger.Get()
 
 	log.Infof("Starting L-IPAMD %s  ...", version.Version)
 	version.RegisterMetric()
 
-	//Check API Server Connectivity
+	// Check API Server Connectivity
 	if err := k8sapi.CheckAPIServerConnectivity(); err != nil {
 		log.Errorf("Failed to check API server connectivity: %s", err)
 		return 1

pkg/k8sapi/k8sutils.go

@@ -23,11 +23,11 @@ import (
 var log = logger.Get()
 
 func InitializeRestMapper() (meta.RESTMapper, error) {
-	restCfg, err := ctrl.GetConfig()
-	restCfg.Burst = 200
+	restCfg, err := getRestConfig()
 	if err != nil {
 		return nil, err
 	}
+	restCfg.Burst = 200
 	mapper, err := apiutil.NewDynamicRESTMapper(restCfg)
 	if err != nil {
 		return nil, err
@@ -37,7 +37,7 @@ func InitializeRestMapper() (meta.RESTMapper, error) {
 
 // CreateKubeClient creates a k8s client
 func CreateKubeClient(mapper meta.RESTMapper) (client.Client, error) {
-	restCfg, err := ctrl.GetConfig()
+	restCfg, err := getRestConfig()
 	if err != nil {
 		return nil, err
 	}
@@ -56,12 +56,12 @@ func CreateKubeClient(mapper meta.RESTMapper) (client.Client, error) {
 
 // CreateKubeClient creates a k8s client
 func CreateCachedKubeClient(rawK8SClient client.Client, mapper meta.RESTMapper) (client.Client, error) {
-	restCfg, err := ctrl.GetConfig()
-	restCfg.Burst = 100
-
+	restCfg, err := getRestConfig()
 	if err != nil {
 		return nil, err
 	}
+	restCfg.Burst = 100
+
 	vpcCniScheme := runtime.NewScheme()
 	clientgoscheme.AddToScheme(vpcCniScheme)
 	eniconfigscheme.AddToScheme(vpcCniScheme)
@@ -89,7 +89,7 @@ func CreateCachedKubeClient(rawK8SClient client.Client, mapper meta.RESTMapper)
 }
 func GetKubeClientSet() (kubernetes.Interface, error) {
 	// creates the in-cluster config
-	config, err := rest.InClusterConfig()
+	config, err := getRestConfig()
 	if err != nil {
 		return nil, err
 	}
@@ -103,7 +103,7 @@ func GetKubeClientSet() (kubernetes.Interface, error) {
 }
 
 func CheckAPIServerConnectivity() error {
-	restCfg, err := ctrl.GetConfig()
+	restCfg, err := getRestConfig()
 	if err != nil {
 		return err
 	}
@@ -130,3 +130,14 @@ func CheckAPIServerConnectivity() error {
 		return true, nil
 	})
 }
+
+func getRestConfig() (*rest.Config, error) {
+	restCfg, err := ctrl.GetConfig()
+	if err != nil {
+		return nil, err
+	}
+	if endpoint, ok := os.LookupEnv("CLUSTER_ENDPOINT"); ok {
+		restCfg.Host = endpoint
+	}
+	return restCfg, nil
+}