Merge pull request kubernetes#127650 from SataQiu/fix-etcd-20240926

kubeadm: fix a bug where the RemoveMember function did not return the correct member list when the member to be removed did not exist

Author: k8s-ci-robot

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

@@ -347,18 +347,19 @@ func (c *Client) ListMembers() ([]Member, error) {
 
 // RemoveMember notifies an etcd cluster to remove an existing member
 func (c *Client) RemoveMember(id uint64) ([]Member, error) {
+	cli, err := c.newEtcdClient(c.Endpoints)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = cli.Close() }()
+
 	// Remove an existing member from the cluster
-	var lastError error
-	var resp *clientv3.MemberRemoveResponse
-	err := wait.PollUntilContextTimeout(context.Background(), constants.EtcdAPICallRetryInterval, constants.EtcdAPICallTimeout,
+	var (
+		lastError   error
+		respMembers []*etcdserverpb.Member
+	)
+	err = wait.PollUntilContextTimeout(context.Background(), constants.EtcdAPICallRetryInterval, constants.EtcdAPICallTimeout,
 		true, func(_ context.Context) (bool, error) {
-			cli, err := c.newEtcdClient(c.Endpoints)
-			if err != nil {
-				lastError = err
-				return false, nil
-			}
-			defer func() { _ = cli.Close() }()
-
 			ctx, cancel := context.WithTimeout(context.Background(), etcdTimeout)
 			defer cancel()
 
@@ -378,16 +379,22 @@ func (c *Client) RemoveMember(id uint64) ([]Member, error) {
 			}
 			if !found {
 				klog.V(5).Infof("Member %s was not found; assuming it was already removed", strconv.FormatUint(id, 16))
+				respMembers = listResp.Members
 				return true, nil
 			}
 
-			resp, err = cli.MemberRemove(ctx, id)
+			resp, err := cli.MemberRemove(ctx, id)
 			if err == nil {
+				respMembers = resp.Members
 				return true, nil
 			}
 			if errors.Is(rpctypes.ErrMemberNotFound, err) {
 				klog.V(5).Infof("Member was already removed, because member %s was not found", strconv.FormatUint(id, 16))
-				return true, nil
+				listResp, err = cli.MemberList(ctx)
+				if err == nil {
+					respMembers = listResp.Members
+					return true, nil
+				}
 			}
 			klog.V(5).Infof("Failed to remove etcd member: %v", err)
 			lastError = err
@@ -399,11 +406,8 @@ func (c *Client) RemoveMember(id uint64) ([]Member, error) {
 
 	// Returns the updated list of etcd members
 	ret := []Member{}
-	if resp != nil {
-		for _, m := range resp.Members {
-			ret = append(ret, Member{Name: m.Name, PeerURL: m.PeerURLs[0]})
-		}
-
+	for _, m := range respMembers {
+		ret = append(ret, Member{Name: m.Name, PeerURL: m.PeerURLs[0]})
 	}
 
 	return ret, nil
@@ -484,7 +488,6 @@ func (c *Client) addMember(name string, peerAddrs string, isLearner bool) ([]Mem
 			// call out to MemberList to fetch all the members before returning.
 			if errors.Is(err, rpctypes.ErrPeerURLExist) {
 				klog.V(5).Info("The peer URL for the added etcd member already exists. Fetching the existing etcd members")
-				var listResp *clientv3.MemberListResponse
 				listResp, err = cli.MemberList(ctx)
 				if err == nil {
 					respMembers = listResp.Members