api: fix resign myself error (#3560)

* api: fix resign myself error

Signed-off-by: ricky <rickif@qq.com>

* api: change resign response

Signed-off-by: ricky <rickif@qq.com>

Co-authored-by: Ti Chi Robot <71242396+ti-chi-bot@users.noreply.github.com>

Author: rickif

server/api/member.go

@@ -275,7 +275,7 @@ func newLeaderHandler(svr *server.Server, rd *render.Render) *leaderHandler {
 // @Tags leader
 // @Summary Get the leader PD server of the cluster.
 // @Produce json
-// @Success 200 {string} string "The transfer command is submitted."
+// @Success 200 {object} pdpb.Member
 // @Router /leader [get]
 func (h *leaderHandler) Get(w http.ResponseWriter, r *http.Request) {
 	h.rd.JSON(w, http.StatusOK, h.svr.GetLeader())
@@ -284,7 +284,7 @@ func (h *leaderHandler) Get(w http.ResponseWriter, r *http.Request) {
 // @Tags leader
 // @Summary Transfer etcd leadership to another PD server.
 // @Produce json
-// @Success 200 {string} string "The transfer command is submitted."
+// @Success 200 {string} string "The resign command is submitted."
 // @Failure 500 {string} string "PD server failed to proceed the request."
 // @Router /leader/resign [post]
 func (h *leaderHandler) Resign(w http.ResponseWriter, r *http.Request) {
@@ -294,7 +294,7 @@ func (h *leaderHandler) Resign(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	h.rd.JSON(w, http.StatusOK, "The transfer command is submitted.")
+	h.rd.JSON(w, http.StatusOK, "The resign command is submitted.")
 }
 
 // @Tags leader

server/api/member_test.go

@@ -17,6 +17,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"math/rand"
 	"net/http"
@@ -30,6 +31,7 @@ import (
 )
 
 var _ = Suite(&testMemberAPISuite{})
+var _ = Suite(&testResignAPISuite{})
 
 type testMemberAPISuite struct {
 	cfgs    []*config.Config
@@ -147,3 +149,26 @@ func changeLeaderPeerUrls(c *C, leader *pdpb.Member, id uint64, urls []string) {
 	c.Assert(err, IsNil)
 	c.Assert(resp.StatusCode, Equals, 204)
 }
+
+type testResignAPISuite struct {
+	cfgs    []*config.Config
+	servers []*server.Server
+	clean   func()
+}
+
+func (s *testResignAPISuite) SetUpSuite(c *C) {
+	s.cfgs, s.servers, s.clean = mustNewCluster(c, 1)
+}
+
+func (s *testResignAPISuite) TearDownSuite(c *C) {
+	s.clean()
+}
+
+func (s *testResignAPISuite) TestResignMyself(c *C) {
+	addr := s.cfgs[0].ClientUrls + apiPrefix + "/api/v1/leader/resign"
+	resp, err := testDialClient.Post(addr, "", nil)
+	c.Assert(err, IsNil)
+	c.Assert(resp.StatusCode, Equals, http.StatusOK)
+	_, _ = io.Copy(ioutil.Discard, resp.Body)
+	resp.Body.Close()
+}

server/member/member.go

@@ -275,6 +275,12 @@ func (m *Member) ResignEtcdLeader(ctx context.Context, from string, nextEtcdLead
 	if err != nil {
 		return err
 	}
+
+	// Do nothing when I am the only member of cluster.
+	if len(res.Members) == 1 && res.Members[0].ID == m.id && nextEtcdLeader == "" {
+		return nil
+	}
+
 	for _, member := range res.Members {
 		if (nextEtcdLeader == "" && member.ID != m.id) || (nextEtcdLeader != "" && member.Name == nextEtcdLeader) {
 			etcdLeaderIDs = append(etcdLeaderIDs, member.GetID())