// getPeerURLsMapAndToken sets up an initial peer URLsMap and cluster token for bootstrap or discovery.
func getPeerURLsMapAndToken(cfg *config, which string) (urlsmap types.URLsMap, token string, err error) {
	switch {
	case cfg.durl != "":
		urlsmap = types.URLsMap{}
		// If using discovery, generate a temporary cluster based on
		// self's advertised peer URLs
		urlsmap[cfg.name] = cfg.apurls
		token = cfg.durl
	case cfg.dnsCluster != "":
		var clusterStr string
		clusterStr, token, err = discovery.SRVGetCluster(cfg.name, cfg.dnsCluster, cfg.initialClusterToken, cfg.apurls)
		if err != nil {
			return nil, "", err
		}
		urlsmap, err = types.NewURLsMap(clusterStr)
		// only etcd member must belong to the discovered cluster.
		// proxy does not need to belong to the discovered cluster.
		if which == "etcd" {
			if _, ok := urlsmap[cfg.name]; !ok {
				return nil, "", fmt.Errorf("cannot find local etcd member %q in SRV records", cfg.name)
			}
		}
	default:
		// We're statically configured, and cluster has appropriately been set.
		urlsmap, err = types.NewURLsMap(cfg.initialCluster)
		token = cfg.initialClusterToken
	}
	return urlsmap, token, err
}

// PeerURLsMapAndToken sets up an initial peer URLsMap and cluster token for bootstrap or discovery.
func (cfg *Config) PeerURLsMapAndToken(which string) (urlsmap types.URLsMap, token string, err error) {
	switch {
	case cfg.Durl != "":
		urlsmap = types.URLsMap{}
		// If using discovery, generate a temporary cluster based on
		// self's advertised peer URLs
		urlsmap[cfg.Name] = cfg.APUrls
		token = cfg.Durl
	case cfg.DNSCluster != "":
		var clusterStr string
		clusterStr, token, err = discovery.SRVGetCluster(cfg.Name, cfg.DNSCluster, cfg.InitialClusterToken, cfg.APUrls)
		if err != nil {
			return nil, "", err
		}
		if strings.Contains(clusterStr, "https://") && cfg.PeerTLSInfo.CAFile == "" {
			cfg.PeerTLSInfo.ServerName = cfg.DNSCluster
		}
		urlsmap, err = types.NewURLsMap(clusterStr)
		// only etcd member must belong to the discovered cluster.
		// proxy does not need to belong to the discovered cluster.
		if which == "etcd" {
			if _, ok := urlsmap[cfg.Name]; !ok {
				return nil, "", fmt.Errorf("cannot find local etcd member %q in SRV records", cfg.Name)
			}
		}
	default:
		// We're statically configured, and cluster has appropriately been set.
		urlsmap, err = types.NewURLsMap(cfg.InitialCluster)
		token = cfg.InitialClusterToken
	}
	return urlsmap, token, err
}

// Clone returns a member with the same server configuration. The returned
// member will not set PeerListeners and ClientListeners.
func (m *member) Clone(t *testing.T) *member {
	mm := &member{}
	mm.ServerConfig = m.ServerConfig

	var err error
	clientURLStrs := m.ClientURLs.StringSlice()
	mm.ClientURLs, err = types.NewURLs(clientURLStrs)
	if err != nil {
		// this should never fail
		panic(err)
	}
	peerURLStrs := m.PeerURLs.StringSlice()
	mm.PeerURLs, err = types.NewURLs(peerURLStrs)
	if err != nil {
		// this should never fail
		panic(err)
	}
	clusterStr := m.InitialPeerURLsMap.String()
	mm.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
	if err != nil {
		// this should never fail
		panic(err)
	}
	mm.InitialClusterToken = m.InitialClusterToken
	mm.ElectionTicks = m.ElectionTicks
	mm.PeerTLSInfo = m.PeerTLSInfo
	mm.ClientTLSInfo = m.ClientTLSInfo
	return mm
}

func (c *cluster) fillClusterForMembers() error {
	if c.cfg.DiscoveryURL != "" {
		// cluster will be discovered
		return nil
	}

	addrs := make([]string, 0)
	for _, m := range c.Members {
		scheme := "http"
		if m.PeerTLSInfo != nil {
			scheme = "https"
		}
		for _, l := range m.PeerListeners {
			addrs = append(addrs, fmt.Sprintf("%s=%s://%s", m.Name, scheme, l.Addr().String()))
		}
	}
	clusterStr := strings.Join(addrs, ",")
	var err error
	for _, m := range c.Members {
		m.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
		if err != nil {
			return err
		}
	}
	return nil
}

// configureTestCluster will set the params to start an etcd server
func configureTestCluster(t *testing.T, name string) *EtcdTestServer {
	var err error
	m := &EtcdTestServer{}

	pln := newLocalListener(t)
	m.PeerListeners = []net.Listener{pln}
	m.PeerURLs, err = types.NewURLs([]string{"http://" + pln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}

	// Allow test launches to control where etcd data goes, for space or performance reasons
	baseDir := os.Getenv("TEST_ETCD_DIR")
	if len(baseDir) == 0 {
		baseDir = os.TempDir()
	}

	m.CertificatesDir, err = ioutil.TempDir(baseDir, "etcd_certificates")
	if err != nil {
		t.Fatal(err)
	}
	m.CertFile = path.Join(m.CertificatesDir, "etcdcert.pem")
	if err = ioutil.WriteFile(m.CertFile, []byte(CertFileContent), 0644); err != nil {
		t.Fatal(err)
	}
	m.KeyFile = path.Join(m.CertificatesDir, "etcdkey.pem")
	if err = ioutil.WriteFile(m.KeyFile, []byte(KeyFileContent), 0644); err != nil {
		t.Fatal(err)
	}
	m.CAFile = path.Join(m.CertificatesDir, "ca.pem")
	if err = ioutil.WriteFile(m.CAFile, []byte(CAFileContent), 0644); err != nil {
		t.Fatal(err)
	}

	cln := newSecuredLocalListener(t, m.CertFile, m.KeyFile, m.CAFile)
	m.ClientListeners = []net.Listener{cln}
	m.ClientURLs, err = types.NewURLs([]string{"https://" + cln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}

	m.Name = name
	m.DataDir, err = ioutil.TempDir(baseDir, "etcd")
	if err != nil {
		t.Fatal(err)
	}

	clusterStr := fmt.Sprintf("%s=http://%s", name, pln.Addr().String())
	m.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
	if err != nil {
		t.Fatal(err)
	}
	m.InitialClusterToken = "TestEtcd"
	m.NewCluster = true
	m.ForceNewCluster = false
	m.ElectionTicks = 10
	m.TickMs = uint(10)

	return m
}

func TestLongestConnected(t *testing.T) {
	umap, err := types.NewURLsMap("mem1=http://10.1:2379,mem2=http://10.2:2379,mem3=http://10.3:2379")
	if err != nil {
		t.Fatal(err)
	}
	clus, err := membership.NewClusterFromURLsMap("test", umap)
	if err != nil {
		t.Fatal(err)
	}
	memberIDs := clus.MemberIDs()

	tr := newNopTransporterWithActiveTime(memberIDs)
	transferee, ok := longestConnected(tr, memberIDs)
	if !ok {
		t.Fatalf("unexpected ok %v", ok)
	}
	if memberIDs[0] != transferee {
		t.Fatalf("expected first member %s to be transferee, got %s", memberIDs[0], transferee)
	}

	// make all members non-active
	amap := make(map[types.ID]time.Time)
	for _, id := range memberIDs {
		amap[id] = time.Time{}
	}
	tr.(*nopTransporterWithActiveTime).reset(amap)

	_, ok2 := longestConnected(tr, memberIDs)
	if ok2 {
		t.Fatalf("unexpected ok %v", ok)
	}
}

// configureTestCluster will set the params to start an etcd server
func configureTestCluster(t *testing.T, name string) *EtcdTestServer {
	var err error
	m := &EtcdTestServer{}

	pln := newLocalListener(t)
	m.PeerListeners = []net.Listener{pln}
	m.PeerURLs, err = types.NewURLs([]string{"http://" + pln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}

	m.CertificatesDir, err = ioutil.TempDir(os.TempDir(), "etcd_certificates")
	if err != nil {
		t.Fatal(err)
	}
	m.CertFile = path.Join(m.CertificatesDir, "etcdcert.pem")
	if err = ioutil.WriteFile(m.CertFile, []byte(CertFileContent), 0644); err != nil {
		t.Fatal(err)
	}
	m.KeyFile = path.Join(m.CertificatesDir, "etcdkey.pem")
	if err = ioutil.WriteFile(m.KeyFile, []byte(KeyFileContent), 0644); err != nil {
		t.Fatal(err)
	}
	m.CAFile = path.Join(m.CertificatesDir, "ca.pem")
	if err = ioutil.WriteFile(m.CAFile, []byte(CAFileContent), 0644); err != nil {
		t.Fatal(err)
	}

	cln := newSecuredLocalListener(t, m.CertFile, m.KeyFile, m.CAFile)
	m.ClientListeners = []net.Listener{cln}
	m.ClientURLs, err = types.NewURLs([]string{"https://" + cln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}

	m.Name = name
	m.DataDir, err = ioutil.TempDir(os.TempDir(), "etcd")
	if err != nil {
		t.Fatal(err)
	}

	clusterStr := fmt.Sprintf("%s=http://%s", name, pln.Addr().String())
	m.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
	if err != nil {
		t.Fatal(err)
	}
	m.Transport, err = transport.NewTimeoutTransport(transport.TLSInfo{}, time.Second, rafthttp.ConnReadTimeout, rafthttp.ConnWriteTimeout)
	if err != nil {
		t.Fatal(err)
	}
	m.NewCluster = true
	m.ForceNewCluster = false
	m.ElectionTicks = 10
	m.TickMs = uint(10)

	return m
}

// mustNewMember return an inited member with the given name. If usePeerTLS is
// true, it will set PeerTLSInfo and use https scheme to communicate between
// peers.
func mustNewMember(t *testing.T, name string, usePeerTLS bool) *member {
	var (
		testTLSInfo = transport.TLSInfo{
			KeyFile:        "./fixtures/server.key.insecure",
			CertFile:       "./fixtures/server.crt",
			TrustedCAFile:  "./fixtures/ca.crt",
			ClientCertAuth: true,
		}
		err error
	)
	m := &member{}

	peerScheme := "http"
	if usePeerTLS {
		peerScheme = "https"
	}

	pln := newLocalListener(t)
	m.PeerListeners = []net.Listener{pln}
	m.PeerURLs, err = types.NewURLs([]string{peerScheme + "://" + pln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}
	if usePeerTLS {
		m.PeerTLSInfo = testTLSInfo
	}

	cln := newLocalListener(t)
	m.ClientListeners = []net.Listener{cln}
	m.ClientURLs, err = types.NewURLs([]string{"http://" + cln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}

	m.Name = name

	m.DataDir, err = ioutil.TempDir(os.TempDir(), "etcd")
	if err != nil {
		t.Fatal(err)
	}
	clusterStr := fmt.Sprintf("%s=%s://%s", name, peerScheme, pln.Addr().String())
	m.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
	if err != nil {
		t.Fatal(err)
	}
	m.InitialClusterToken = clusterName
	m.NewCluster = true
	m.ServerConfig.PeerTLSInfo = m.PeerTLSInfo
	m.ElectionTicks = electionTicks
	m.TickMs = uint(tickDuration / time.Millisecond)
	return m
}

// getPeerURLsMapAndToken sets up an initial peer URLsMap and cluster token for bootstrap or discovery.
func getPeerURLsMapAndToken(cfg *config) (urlsmap types.URLsMap, token string, err error) {
	switch {
	case cfg.durl != "":
		urlsmap = types.URLsMap{}
		// If using discovery, generate a temporary cluster based on
		// self's advertised peer URLs
		urlsmap[cfg.name] = cfg.apurls
		token = cfg.durl
	case cfg.dnsCluster != "":
		var clusterStr string
		clusterStr, token, err = discovery.SRVGetCluster(cfg.name, cfg.dnsCluster, cfg.initialClusterToken, cfg.apurls)
		if err != nil {
			return nil, "", err
		}
		urlsmap, err = types.NewURLsMap(clusterStr)
	default:
		// We're statically configured, and cluster has appropriately been set.
		urlsmap, err = types.NewURLsMap(cfg.initialCluster)
		token = cfg.initialClusterToken
	}
	return urlsmap, token, err
}

// mustNewMember return an inited member with the given name. If peerTLS is
// set, it will use https scheme to communicate between peers.
func mustNewMember(t *testing.T, mcfg memberConfig) *member {
	var err error
	m := &member{}

	peerScheme, clientScheme := "http", "http"
	if mcfg.peerTLS != nil {
		peerScheme = "https"
	}
	if mcfg.clientTLS != nil {
		clientScheme = "https"
	}

	pln := newLocalListener(t)
	m.PeerListeners = []net.Listener{pln}
	m.PeerURLs, err = types.NewURLs([]string{peerScheme + "://" + pln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}
	m.PeerTLSInfo = mcfg.peerTLS

	cln := newLocalListener(t)
	m.ClientListeners = []net.Listener{cln}
	m.ClientURLs, err = types.NewURLs([]string{clientScheme + "://" + cln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}
	m.ClientTLSInfo = mcfg.clientTLS

	m.Name = mcfg.name

	m.DataDir, err = ioutil.TempDir(os.TempDir(), "etcd")
	if err != nil {
		t.Fatal(err)
	}
	clusterStr := fmt.Sprintf("%s=%s://%s", mcfg.name, peerScheme, pln.Addr().String())
	m.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
	if err != nil {
		t.Fatal(err)
	}
	m.InitialClusterToken = clusterName
	m.NewCluster = true
	m.BootstrapTimeout = 10 * time.Millisecond
	if m.PeerTLSInfo != nil {
		m.ServerConfig.PeerTLSInfo = *m.PeerTLSInfo
	}
	m.ElectionTicks = electionTicks
	m.TickMs = uint(tickDuration / time.Millisecond)
	m.QuotaBackendBytes = mcfg.quotaBackendBytes
	return m
}

func nodesToCluster(ns []*client.Node, size int) (string, error) {
	s := make([]string, len(ns))
	for i, n := range ns {
		s[i] = n.Value
	}
	us := strings.Join(s, ",")
	m, err := types.NewURLsMap(us)
	if err != nil {
		return us, ErrInvalidURL
	}
	if m.Len() != size {
		return us, ErrDuplicateName
	}
	return us, nil
}

func TestConfigVerifyExistingWithDiscoveryURLFail(t *testing.T) {
	cluster, err := types.NewURLsMap("node1=http://127.0.0.1:2380")
	if err != nil {
		t.Fatalf("NewCluster error: %v", err)
	}
	c := &ServerConfig{
		Name:               "node1",
		DiscoveryURL:       "http://127.0.0.1:2379/abcdefg",
		PeerURLs:           mustNewURLs(t, []string{"http://127.0.0.1:2380"}),
		InitialPeerURLsMap: cluster,
		NewCluster:         false,
	}
	if err := c.VerifyJoinExisting(); err == nil {
		t.Errorf("err = nil, want not nil")
	}
}

func snapshotRestoreCommandFunc(cmd *cobra.Command, args []string) {
	if len(args) != 1 {
		err := fmt.Errorf("snapshot restore requires exactly one argument")
		ExitWithError(ExitBadArgs, err)
	}

	urlmap, uerr := types.NewURLsMap(restoreCluster)
	if uerr != nil {
		ExitWithError(ExitBadArgs, uerr)
	}

	cfg := etcdserver.ServerConfig{
		InitialClusterToken: restoreClusterToken,
		InitialPeerURLsMap:  urlmap,
		PeerURLs:            types.MustNewURLs(strings.Split(restorePeerURLs, ",")),
		Name:                restoreName,
	}
	if err := cfg.VerifyBootstrap(); err != nil {
		ExitWithError(ExitBadArgs, err)
	}

	cl, cerr := membership.NewClusterFromURLsMap(restoreClusterToken, urlmap)
	if cerr != nil {
		ExitWithError(ExitBadArgs, cerr)
	}

	basedir := restoreDataDir
	if basedir == "" {
		basedir = restoreName + ".etcd"
	}

	waldir := path.Join(basedir, "member", "wal")
	snapdir := path.Join(basedir, "member", "snap")

	if _, err := os.Stat(basedir); err == nil {
		ExitWithError(ExitInvalidInput, fmt.Errorf("data-dir %q exists", basedir))
	}

	makeDB(snapdir, args[0])
	makeWAL(waldir, cl)
}

func fillClusterForMembers(ms []*member) error {
	addrs := make([]string, 0)
	for _, m := range ms {
		scheme := "http"
		if !m.PeerTLSInfo.Empty() {
			scheme = "https"
		}
		for _, l := range m.PeerListeners {
			addrs = append(addrs, fmt.Sprintf("%s=%s://%s", m.Name, scheme, l.Addr().String()))
		}
	}
	clusterStr := strings.Join(addrs, ",")
	var err error
	for _, m := range ms {
		m.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
		if err != nil {
			return err
		}
	}
	return nil
}

// configureTestCluster will set the params to start an etcd server
func configureTestCluster(t *testing.T, name string) *EtcdTestServer {
	var err error
	m := &EtcdTestServer{}

	pln := newLocalListener(t)
	m.PeerListeners = []net.Listener{pln}
	m.PeerURLs, err = types.NewURLs([]string{"http://" + pln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}

	cln := newLocalListener(t)
	m.ClientListeners = []net.Listener{cln}
	m.ClientURLs, err = types.NewURLs([]string{"http://" + cln.Addr().String()})
	if err != nil {
		t.Fatal(err)
	}

	m.Name = name
	m.DataDir, err = ioutil.TempDir(os.TempDir(), "etcd")
	if err != nil {
		t.Fatal(err)
	}

	clusterStr := fmt.Sprintf("%s=http://%s", name, pln.Addr().String())
	m.InitialPeerURLsMap, err = types.NewURLsMap(clusterStr)
	if err != nil {
		t.Fatal(err)
	}
	m.Transport, err = transport.NewTimeoutTransport(transport.TLSInfo{}, time.Second, rafthttp.ConnReadTimeout, rafthttp.ConnWriteTimeout)
	if err != nil {
		t.Fatal(err)
	}
	m.NewCluster = true
	m.ForceNewCluster = false
	m.ElectionTicks = 10
	m.TickMs = uint(10)

	return m
}

// NewServer creates a new EtcdServer from the supplied configuration. The
// configuration is considered static for the lifetime of the EtcdServer.
func NewServer(cfg *ServerConfig) (srv *EtcdServer, err error) {
	st := store.New(StoreClusterPrefix, StoreKeysPrefix)

	var (
		w  *wal.WAL
		n  raft.Node
		s  *raft.MemoryStorage
		id types.ID
		cl *membership.RaftCluster
	)

	if terr := fileutil.TouchDirAll(cfg.DataDir); terr != nil {
		return nil, fmt.Errorf("cannot access data directory: %v", terr)
	}

	// Run the migrations.
	dataVer, err := version.DetectDataDir(cfg.DataDir)
	if err != nil {
		return nil, err
	}
	if err = upgradeDataDir(cfg.DataDir, cfg.Name, dataVer); err != nil {
		return nil, err
	}

	haveWAL := wal.Exist(cfg.WALDir())

	if err = os.MkdirAll(cfg.SnapDir(), privateDirMode); err != nil && !os.IsExist(err) {
		plog.Fatalf("create snapshot directory error: %v", err)
	}
	ss := snap.New(cfg.SnapDir())
	be := backend.NewDefaultBackend(path.Join(cfg.SnapDir(), databaseFilename))
	defer func() {
		if err != nil {
			be.Close()
		}
	}()

	prt, err := rafthttp.NewRoundTripper(cfg.PeerTLSInfo, cfg.peerDialTimeout())
	if err != nil {
		return nil, err
	}
	var remotes []*membership.Member
	switch {
	case !haveWAL && !cfg.NewCluster:
		if err = cfg.VerifyJoinExisting(); err != nil {
			return nil, err
		}
		cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
		if err != nil {
			return nil, err
		}
		existingCluster, gerr := GetClusterFromRemotePeers(getRemotePeerURLs(cl, cfg.Name), prt)
		if gerr != nil {
			return nil, fmt.Errorf("cannot fetch cluster info from peer urls: %v", gerr)
		}
		if err = membership.ValidateClusterAndAssignIDs(cl, existingCluster); err != nil {
			return nil, fmt.Errorf("error validating peerURLs %s: %v", existingCluster, err)
		}
		if !isCompatibleWithCluster(cl, cl.MemberByName(cfg.Name).ID, prt) {
			return nil, fmt.Errorf("incomptible with current running cluster")
		}

		remotes = existingCluster.Members()
		cl.SetID(existingCluster.ID())
		cl.SetStore(st)
		cl.SetBackend(be)
		cfg.Print()
		id, n, s, w = startNode(cfg, cl, nil)
	case !haveWAL && cfg.NewCluster:
		if err = cfg.VerifyBootstrap(); err != nil {
			return nil, err
		}
		cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
		if err != nil {
			return nil, err
		}
		m := cl.MemberByName(cfg.Name)
		if isMemberBootstrapped(cl, cfg.Name, prt, cfg.bootstrapTimeout()) {
			return nil, fmt.Errorf("member %s has already been bootstrapped", m.ID)
		}
		if cfg.ShouldDiscover() {
			var str string
			str, err = discovery.JoinCluster(cfg.DiscoveryURL, cfg.DiscoveryProxy, m.ID, cfg.InitialPeerURLsMap.String())
			if err != nil {
				return nil, &DiscoveryError{Op: "join", Err: err}
			}
			var urlsmap types.URLsMap
			urlsmap, err = types.NewURLsMap(str)
			if err != nil {
				return nil, err
			}
			if checkDuplicateURL(urlsmap) {
				return nil, fmt.Errorf("discovery cluster %s has duplicate url", urlsmap)
			}
			if cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, urlsmap); err != nil {
				return nil, err
			}
		}
//.........这里部分代码省略.........

//.........这里部分代码省略.........
		}
		if err = membership.ValidateClusterAndAssignIDs(cl, existingCluster); err != nil {
			return nil, fmt.Errorf("error validating peerURLs %s: %v", existingCluster, err)
		}
		if !isCompatibleWithCluster(cl, cl.MemberByName(cfg.Name).ID, prt) {
			return nil, fmt.Errorf("incompatible with current running cluster")
		}

		remotes = existingCluster.Members()
		cl.SetID(existingCluster.ID())
		cl.SetStore(st)
		cl.SetBackend(be)
		cfg.Print()
		id, n, s, w = startNode(cfg, cl, nil)
	case !haveWAL && cfg.NewCluster:
		if err = cfg.VerifyBootstrap(); err != nil {
			return nil, err
		}
		cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
		if err != nil {
			return nil, err
		}
		m := cl.MemberByName(cfg.Name)
		if isMemberBootstrapped(cl, cfg.Name, prt, cfg.bootstrapTimeout()) {
			return nil, fmt.Errorf("member %s has already been bootstrapped", m.ID)
		}
		if cfg.ShouldDiscover() {
			var str string
			str, err = discovery.JoinCluster(cfg.DiscoveryURL, cfg.DiscoveryProxy, m.ID, cfg.InitialPeerURLsMap.String())
			if err != nil {
				return nil, &DiscoveryError{Op: "join", Err: err}
			}
			var urlsmap types.URLsMap
			urlsmap, err = types.NewURLsMap(str)
			if err != nil {
				return nil, err
			}
			if checkDuplicateURL(urlsmap) {
				return nil, fmt.Errorf("discovery cluster %s has duplicate url", urlsmap)
			}
			if cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, urlsmap); err != nil {
				return nil, err
			}
		}
		cl.SetStore(st)
		cl.SetBackend(be)
		cfg.PrintWithInitial()
		id, n, s, w = startNode(cfg, cl, cl.MemberIDs())
	case haveWAL:
		if err = fileutil.IsDirWriteable(cfg.MemberDir()); err != nil {
			return nil, fmt.Errorf("cannot write to member directory: %v", err)
		}

		if err = fileutil.IsDirWriteable(cfg.WALDir()); err != nil {
			return nil, fmt.Errorf("cannot write to WAL directory: %v", err)
		}

		if cfg.ShouldDiscover() {
			plog.Warningf("discovery token ignored since a cluster has already been initialized. Valid log found at %q", cfg.WALDir())
		}
		snapshot, err = ss.Load()
		if err != nil && err != snap.ErrNoSnapshot {
			return nil, err
		}
		if snapshot != nil {
			if err = st.Recovery(snapshot.Data); err != nil {

// setupCluster sets up an initial cluster definition for bootstrap or discovery.
func setupCluster(cfg *config) (types.URLsMap, string, error) {
	// We're statically configured, and cluster has appropriately been set.
	m, err := types.NewURLsMap(cfg.initialCluster)
	return m, cfg.initialClusterToken, err
}

// startProxy launches an HTTP proxy for client communication which proxies to other etcd nodes.
func startProxy(cfg *config) error {
	urlsmap, _, err := getPeerURLsMapAndToken(cfg, "proxy")
	if err != nil {
		return fmt.Errorf("error setting up initial cluster: %v", err)
	}

	pt, err := transport.NewTimeoutTransport(cfg.peerTLSInfo, time.Duration(cfg.proxyDialTimeoutMs)*time.Millisecond, time.Duration(cfg.proxyReadTimeoutMs)*time.Millisecond, time.Duration(cfg.proxyWriteTimeoutMs)*time.Millisecond)
	if err != nil {
		return err
	}
	pt.MaxIdleConnsPerHost = proxy.DefaultMaxIdleConnsPerHost

	tr, err := transport.NewTimeoutTransport(cfg.peerTLSInfo, time.Duration(cfg.proxyDialTimeoutMs)*time.Millisecond, time.Duration(cfg.proxyReadTimeoutMs)*time.Millisecond, time.Duration(cfg.proxyWriteTimeoutMs)*time.Millisecond)
	if err != nil {
		return err
	}

	cfg.dir = path.Join(cfg.dir, "proxy")
	err = os.MkdirAll(cfg.dir, 0700)
	if err != nil {
		return err
	}

	var peerURLs []string
	clusterfile := path.Join(cfg.dir, "cluster")

	b, err := ioutil.ReadFile(clusterfile)
	switch {
	case err == nil:
		if cfg.durl != "" {
			plog.Warningf("discovery token ignored since the proxy has already been initialized. Valid cluster file found at %q", clusterfile)
		}
		urls := struct{ PeerURLs []string }{}
		err := json.Unmarshal(b, &urls)
		if err != nil {
			return err
		}
		peerURLs = urls.PeerURLs
		plog.Infof("proxy: using peer urls %v from cluster file %q", peerURLs, clusterfile)
	case os.IsNotExist(err):
		if cfg.durl != "" {
			s, err := discovery.GetCluster(cfg.durl, cfg.dproxy)
			if err != nil {
				return err
			}
			if urlsmap, err = types.NewURLsMap(s); err != nil {
				return err
			}
		}
		peerURLs = urlsmap.URLs()
		plog.Infof("proxy: using peer urls %v ", peerURLs)
	default:
		return err
	}

	clientURLs := []string{}
	uf := func() []string {
		gcls, err := etcdserver.GetClusterFromRemotePeers(peerURLs, tr)
		// TODO: remove the 2nd check when we fix GetClusterFromPeers
		// GetClusterFromPeers should not return nil error with an invalid empty cluster
		if err != nil {
			plog.Warningf("proxy: %v", err)
			return []string{}
		}
		if len(gcls.Members()) == 0 {
			return clientURLs
		}
		clientURLs = gcls.ClientURLs()

		urls := struct{ PeerURLs []string }{gcls.PeerURLs()}
		b, err := json.Marshal(urls)
		if err != nil {
			plog.Warningf("proxy: error on marshal peer urls %s", err)
			return clientURLs
		}

		err = ioutil.WriteFile(clusterfile+".bak", b, 0600)
		if err != nil {
			plog.Warningf("proxy: error on writing urls %s", err)
			return clientURLs
		}
		err = os.Rename(clusterfile+".bak", clusterfile)
		if err != nil {
			plog.Warningf("proxy: error on updating clusterfile %s", err)
			return clientURLs
		}
		if !reflect.DeepEqual(gcls.PeerURLs(), peerURLs) {
			plog.Noticef("proxy: updated peer urls in cluster file from %v to %v", peerURLs, gcls.PeerURLs())
		}
		peerURLs = gcls.PeerURLs()

		return clientURLs
	}
	ph := proxy.NewHandler(pt, uf, time.Duration(cfg.proxyFailureWaitMs)*time.Millisecond, time.Duration(cfg.proxyRefreshIntervalMs)*time.Millisecond)
	ph = &cors.CORSHandler{
		Handler: ph,
		Info:    cfg.corsInfo,
	}

//.........这里部分代码省略.........

// startProxy launches an HTTP proxy for client communication which proxies to other etcd nodes.
func startProxy(cfg *config) error {
	plog.Notice("proxy: this proxy supports v2 API only!")

	pt, err := transport.NewTimeoutTransport(cfg.PeerTLSInfo, time.Duration(cfg.ProxyDialTimeoutMs)*time.Millisecond, time.Duration(cfg.ProxyReadTimeoutMs)*time.Millisecond, time.Duration(cfg.ProxyWriteTimeoutMs)*time.Millisecond)
	if err != nil {
		return err
	}
	pt.MaxIdleConnsPerHost = httpproxy.DefaultMaxIdleConnsPerHost

	tr, err := transport.NewTimeoutTransport(cfg.PeerTLSInfo, time.Duration(cfg.ProxyDialTimeoutMs)*time.Millisecond, time.Duration(cfg.ProxyReadTimeoutMs)*time.Millisecond, time.Duration(cfg.ProxyWriteTimeoutMs)*time.Millisecond)
	if err != nil {
		return err
	}

	cfg.Dir = path.Join(cfg.Dir, "proxy")
	err = os.MkdirAll(cfg.Dir, fileutil.PrivateDirMode)
	if err != nil {
		return err
	}

	var peerURLs []string
	clusterfile := path.Join(cfg.Dir, "cluster")

	b, err := ioutil.ReadFile(clusterfile)
	switch {
	case err == nil:
		if cfg.Durl != "" {
			plog.Warningf("discovery token ignored since the proxy has already been initialized. Valid cluster file found at %q", clusterfile)
		}
		if cfg.DNSCluster != "" {
			plog.Warningf("DNS SRV discovery ignored since the proxy has already been initialized. Valid cluster file found at %q", clusterfile)
		}
		urls := struct{ PeerURLs []string }{}
		err = json.Unmarshal(b, &urls)
		if err != nil {
			return err
		}
		peerURLs = urls.PeerURLs
		plog.Infof("proxy: using peer urls %v from cluster file %q", peerURLs, clusterfile)
	case os.IsNotExist(err):
		var urlsmap types.URLsMap
		urlsmap, _, err = cfg.PeerURLsMapAndToken("proxy")
		if err != nil {
			return fmt.Errorf("error setting up initial cluster: %v", err)
		}

		if cfg.Durl != "" {
			var s string
			s, err = discovery.GetCluster(cfg.Durl, cfg.Dproxy)
			if err != nil {
				return err
			}
			if urlsmap, err = types.NewURLsMap(s); err != nil {
				return err
			}
		}
		peerURLs = urlsmap.URLs()
		plog.Infof("proxy: using peer urls %v ", peerURLs)
	default:
		return err
	}

	clientURLs := []string{}
	uf := func() []string {
		gcls, gerr := etcdserver.GetClusterFromRemotePeers(peerURLs, tr)

		if gerr != nil {
			plog.Warningf("proxy: %v", gerr)
			return []string{}
		}

		clientURLs = gcls.ClientURLs()

		urls := struct{ PeerURLs []string }{gcls.PeerURLs()}
		b, jerr := json.Marshal(urls)
		if jerr != nil {
			plog.Warningf("proxy: error on marshal peer urls %s", jerr)
			return clientURLs
		}

		err = pkgioutil.WriteAndSyncFile(clusterfile+".bak", b, 0600)
		if err != nil {
			plog.Warningf("proxy: error on writing urls %s", err)
			return clientURLs
		}
		err = os.Rename(clusterfile+".bak", clusterfile)
		if err != nil {
			plog.Warningf("proxy: error on updating clusterfile %s", err)
			return clientURLs
		}
		if !reflect.DeepEqual(gcls.PeerURLs(), peerURLs) {
			plog.Noticef("proxy: updated peer urls in cluster file from %v to %v", peerURLs, gcls.PeerURLs())
		}
		peerURLs = gcls.PeerURLs()

		return clientURLs
	}
	ph := httpproxy.NewHandler(pt, uf, time.Duration(cfg.ProxyFailureWaitMs)*time.Millisecond, time.Duration(cfg.ProxyRefreshIntervalMs)*time.Millisecond)
	ph = &cors.CORSHandler{
//.........这里部分代码省略.........