Merge pull request #11093 from olemarkus/protokube-eager-connect

Ensure protokube can connect to kube-apiserver before starting the sync loop

protokube/pkg/protokube/kube_boot.go

@@ -18,10 +18,12 @@ package protokube
 
 import (
 	"context"
+	"fmt"
 	"net"
 	"path/filepath"
 	"time"
 
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/klog/v2"
 )
 
@@ -101,8 +103,24 @@ func (k *KubeBoot) Init(volumesProvider Volumes) {
 
 // RunSyncLoop is responsible for provision the cluster
 func (k *KubeBoot) RunSyncLoop() {
-	for {
 	ctx := context.Background()
+
+	client, err := k.Kubernetes.KubernetesClient()
+	if err != nil {
+		panic(fmt.Sprintf("could not create kubernetes client: %v", err))
+	}
+
+	klog.Info("polling for apiserver readiness")
+	for {
+		_, err = client.CoreV1().Namespaces().Get(ctx, "kube-system", metav1.GetOptions{})
+		if err == nil {
+			klog.Info("successfully connected to the apiserver")
+			break
+		}
+		klog.Infof("failed to connect to the apiserver (will sleep and retry): %v", err)
+		time.Sleep(5 * time.Second)
+	}
+	for {
 		if err := k.syncOnce(ctx); err != nil {
 			klog.Warningf("error during attempt to bootstrap (will sleep and retry): %v", err)
 		}