Automated cherry pick of #92118: kubeadm: don't re-add an etcd member if it already exists for

cmd/kubeadm/app/phases/etcd/local.go

@@ -130,16 +130,36 @@ func CreateStackedEtcdStaticPodManifestFile(client clientset.Interface, manifest
 		return err
 	}
 
-	// notifies the other members of the etcd cluster about the joining member
 	etcdPeerAddress := etcdutil.GetPeerURL(endpoint)
 
-	klog.V(1).Infof("Adding etcd member: %s", etcdPeerAddress)
-	initialCluster, err := etcdClient.AddMember(nodeName, etcdPeerAddress)
+	klog.V(1).Infoln("[etcd] Getting the list of existing members")
+	initialCluster, err := etcdClient.ListMembers()
 	if err != nil {
 		return err
 	}
-	fmt.Println("[etcd] Announced new etcd member joining to the existing etcd cluster")
-	klog.V(1).Infof("Updated etcd member list: %v", initialCluster)
+
+	// only add the new member if it doesn't already exists
+	var exists bool
+	klog.V(1).Infof("[etcd] Checking if the etcd member already exists: %s", etcdPeerAddress)
+	for _, member := range initialCluster {
+		if member.PeerURL == etcdPeerAddress {
+			exists = true
+			break
+		}
+	}
+
+	if exists {
+		klog.V(1).Infof("[etcd] Etcd member already exists: %s", etcdPeerAddress)
+	} else {
+		klog.V(1).Infof("[etcd] Adding etcd member: %s", etcdPeerAddress)
+		initialCluster, err = etcdClient.AddMember(nodeName, etcdPeerAddress)
+		if err != nil {
+			return err
+		}
+
+		fmt.Println("[etcd] Announced new etcd member joining to the existing etcd cluster")
+		klog.V(1).Infof("Updated etcd member list: %v", initialCluster)
+	}
 
 	fmt.Printf("[etcd] Creating static Pod manifest for %q\n", kubeadmconstants.Etcd)
 

cmd/kubeadm/app/phases/upgrade/compute_test.go

@@ -121,6 +121,10 @@ func (f fakeEtcdClient) RemoveMember(id uint64) ([]etcdutil.Member, error) {
 	return []etcdutil.Member{}, nil
 }
 
+func (f fakeEtcdClient) ListMembers() ([]etcdutil.Member, error) {
+	return []etcdutil.Member{}, nil
+}
+
 func getEtcdVersion(v *versionutil.Version) string {
 	return constants.SupportedEtcdVersion[uint8(v.Minor())]
 }

cmd/kubeadm/app/phases/upgrade/staticpods_test.go

@@ -268,6 +268,10 @@ func (c fakeTLSEtcdClient) RemoveMember(id uint64) ([]etcdutil.Member, error) {
 	return []etcdutil.Member{}, nil
 }
 
+func (c fakeTLSEtcdClient) ListMembers() ([]etcdutil.Member, error) {
+	return []etcdutil.Member{}, nil
+}
+
 type fakePodManifestEtcdClient struct{ ManifestDir, CertificatesDir string }
 
 func (c fakePodManifestEtcdClient) WaitForClusterAvailable(retries int, retryInterval time.Duration) (bool, error) {
@@ -309,6 +313,10 @@ func (c fakePodManifestEtcdClient) RemoveMember(id uint64) ([]etcdutil.Member, e
 	return []etcdutil.Member{}, nil
 }
 
+func (c fakePodManifestEtcdClient) ListMembers() ([]etcdutil.Member, error) {
+	return []etcdutil.Member{}, nil
+}
+
 func TestStaticPodControlPlane(t *testing.T) {
 	tests := []struct {
 		description          string

cmd/kubeadm/app/util/etcd/etcd.go

@@ -55,6 +55,7 @@ type ClusterInterrogator interface {
 	GetVersion() (string, error)
 	WaitForClusterAvailable(retries int, retryInterval time.Duration) (bool, error)
 	Sync() error
+	ListMembers() ([]Member, error)
 	AddMember(name string, peerAddrs string) ([]Member, error)
 	GetMemberID(peerURL string) (uint64, error)
 	RemoveMember(id uint64) ([]Member, error)
@@ -176,8 +177,36 @@ type Member struct {
 	PeerURL string
 }
 
+// ListMembers returns the member list.
+func (c *Client) ListMembers() ([]Member, error) {
+	resp, err := c.listMembers()
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make([]Member, 0, len(resp.Members))
+	for _, m := range resp.Members {
+		ret = append(ret, Member{Name: m.Name, PeerURL: m.PeerURLs[0]})
+	}
+	return ret, nil
+}
+
 // GetMemberID returns the member ID of the given peer URL
 func (c *Client) GetMemberID(peerURL string) (uint64, error) {
+	resp, err := c.listMembers()
+	if err != nil {
+		return 0, err
+	}
+
+	for _, member := range resp.Members {
+		if member.GetPeerURLs()[0] == peerURL {
+			return member.GetID(), nil
+		}
+	}
+	return 0, nil
+}
+
+func (c *Client) listMembers() (*clientv3.MemberListResponse, error) {
 	cli, err := clientv3.New(clientv3.Config{
 		Endpoints:   c.Endpoints,
 		DialTimeout: dialTimeout,
@@ -187,7 +216,7 @@ func (c *Client) GetMemberID(peerURL string) (uint64, error) {
 		TLS: c.TLS,
 	})
 	if err != nil {
-		return 0, err
+		return nil, err
 	}
 	defer cli.Close()
 
@@ -206,15 +235,9 @@ func (c *Client) GetMemberID(peerURL string) (uint64, error) {
 		return false, nil
 	})
 	if err != nil {
-		return 0, lastError
-	}
-
-	for _, member := range resp.Members {
-		if member.GetPeerURLs()[0] == peerURL {
-			return member.GetID(), nil
-		}
+		return nil, lastError
 	}
-	return 0, nil
+	return resp, nil
 }
 
 // RemoveMember notifies an etcd cluster to remove an existing member