Beispiel #1
0
// getRemotePeerURLs returns peer urls of remote members in the cluster. The
// returned list is sorted in ascending lexicographical order.
func getRemotePeerURLs(cl *membership.RaftCluster, local string) []string {
	us := make([]string, 0)
	for _, m := range cl.Members() {
		if m.Name == local {
			continue
		}
		us = append(us, m.PeerURLs...)
	}
	sort.Strings(us)
	return us
}
Beispiel #2
0
// isMemberBootstrapped tries to check if the given member has been bootstrapped
// in the given cluster.
func isMemberBootstrapped(cl *membership.RaftCluster, member string, rt http.RoundTripper, timeout time.Duration) bool {
	rcl, err := getClusterFromRemotePeers(getRemotePeerURLs(cl, member), timeout, false, rt)
	if err != nil {
		return false
	}
	id := cl.MemberByName(member).ID
	m := rcl.Member(id)
	if m == nil {
		return false
	}
	if len(m.ClientURLs) > 0 {
		return true
	}
	return false
}
Beispiel #3
0
// makeWAL creates a WAL for the initial cluster
func makeWAL(waldir string, cl *membership.RaftCluster) {
	if err := os.MkdirAll(waldir, 0755); err != nil {
		ExitWithError(ExitIO, err)
	}

	m := cl.MemberByName(restoreName)
	md := &etcdserverpb.Metadata{NodeID: uint64(m.ID), ClusterID: uint64(cl.ID())}
	metadata, merr := md.Marshal()
	if merr != nil {
		ExitWithError(ExitInvalidInput, merr)
	}

	w, walerr := wal.Create(waldir, metadata)
	if walerr != nil {
		ExitWithError(ExitIO, walerr)
	}
	defer w.Close()

	peers := make([]raft.Peer, len(cl.MemberIDs()))
	for i, id := range cl.MemberIDs() {
		ctx, err := json.Marshal((*cl).Member(id))
		if err != nil {
			ExitWithError(ExitInvalidInput, err)
		}
		peers[i] = raft.Peer{ID: uint64(id), Context: ctx}
	}

	ents := make([]raftpb.Entry, len(peers))
	for i, p := range peers {
		cc := raftpb.ConfChange{
			Type:    raftpb.ConfChangeAddNode,
			NodeID:  p.ID,
			Context: p.Context}
		d, err := cc.Marshal()
		if err != nil {
			ExitWithError(ExitInvalidInput, err)
		}
		e := raftpb.Entry{
			Type:  raftpb.EntryConfChange,
			Term:  1,
			Index: uint64(i + 1),
			Data:  d,
		}
		ents[i] = e
	}

	w.Save(raftpb.HardState{
		Term:   1,
		Vote:   peers[0].ID,
		Commit: uint64(len(ents))}, ents)
}
Beispiel #4
0
func applyConf(cc raftpb.ConfChange, cl *membership.RaftCluster) {
	if err := cl.ValidateConfigurationChange(cc); err != nil {
		return
	}
	switch cc.Type {
	case raftpb.ConfChangeAddNode:
		m := new(membership.Member)
		if err := json.Unmarshal(cc.Context, m); err != nil {
			panic(err)
		}
		cl.AddMember(m)
	case raftpb.ConfChangeRemoveNode:
		cl.RemoveMember(types.ID(cc.NodeID))
	case raftpb.ConfChangeUpdateNode:
		m := new(membership.Member)
		if err := json.Unmarshal(cc.Context, m); err != nil {
			panic(err)
		}
		cl.UpdateRaftAttributes(m.ID, m.RaftAttributes)
	}
}
Beispiel #5
0
func startNode(cfg *ServerConfig, cl *membership.RaftCluster, ids []types.ID) (id types.ID, n raft.Node, s *raft.MemoryStorage, w *wal.WAL) {
	var err error
	member := cl.MemberByName(cfg.Name)
	metadata := pbutil.MustMarshal(
		&pb.Metadata{
			NodeID:    uint64(member.ID),
			ClusterID: uint64(cl.ID()),
		},
	)
	if err = os.MkdirAll(cfg.SnapDir(), privateDirMode); err != nil {
		plog.Fatalf("create snapshot directory error: %v", err)
	}
	if w, err = wal.Create(cfg.WALDir(), metadata); err != nil {
		plog.Fatalf("create wal error: %v", err)
	}
	peers := make([]raft.Peer, len(ids))
	for i, id := range ids {
		ctx, err := json.Marshal((*cl).Member(id))
		if err != nil {
			plog.Panicf("marshal member should never fail: %v", err)
		}
		peers[i] = raft.Peer{ID: uint64(id), Context: ctx}
	}
	id = member.ID
	plog.Infof("starting member %s in cluster %s", id, cl.ID())
	s = raft.NewMemoryStorage()
	c := &raft.Config{
		ID:              uint64(id),
		ElectionTick:    cfg.ElectionTicks,
		HeartbeatTick:   1,
		Storage:         s,
		MaxSizePerMsg:   maxSizePerMsg,
		MaxInflightMsgs: maxInflightMsgs,
		CheckQuorum:     true,
	}

	n = raft.StartNode(c, peers)
	raftStatusMu.Lock()
	raftStatus = n.Status
	raftStatusMu.Unlock()
	advanceTicksForElection(n, c.ElectionTick)
	return
}
Beispiel #6
0
// getVersions returns the versions of the members in the given cluster.
// The key of the returned map is the member's ID. The value of the returned map
// is the semver versions string, including server and cluster.
// If it fails to get the version of a member, the key will be nil.
func getVersions(cl *membership.RaftCluster, local types.ID, rt http.RoundTripper) map[string]*version.Versions {
	members := cl.Members()
	vers := make(map[string]*version.Versions)
	for _, m := range members {
		if m.ID == local {
			cv := "not_decided"
			if cl.Version() != nil {
				cv = cl.Version().String()
			}
			vers[m.ID.String()] = &version.Versions{Server: version.Version, Cluster: cv}
			continue
		}
		ver, err := getVersion(m, rt)
		if err != nil {
			plog.Warningf("cannot get the version of member %s (%v)", m.ID, err)
			vers[m.ID.String()] = nil
		} else {
			vers[m.ID.String()] = ver
		}
	}
	return vers
}
Beispiel #7
0
// 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
			}
		}
		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())
		}
		var snapshot *raftpb.Snapshot
		snapshot, err = ss.Load()
		if err != nil && err != snap.ErrNoSnapshot {
			return nil, err
		}
		if snapshot != nil {
			if err = st.Recovery(snapshot.Data); err != nil {
				plog.Panicf("recovered store from snapshot error: %v", err)
			}
			plog.Infof("recovered store from snapshot at index %d", snapshot.Metadata.Index)
		}
		cfg.Print()
		if !cfg.ForceNewCluster {
			id, cl, n, s, w = restartNode(cfg, snapshot)
		} else {
			id, cl, n, s, w = restartAsStandaloneNode(cfg, snapshot)
		}
		cl.SetStore(st)
		cl.SetBackend(be)
		cl.Recover()
	default:
		return nil, fmt.Errorf("unsupported bootstrap config")
	}

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

	sstats := &stats.ServerStats{
		Name: cfg.Name,
		ID:   id.String(),
	}
	sstats.Initialize()
	lstats := stats.NewLeaderStats(id.String())

	srv = &EtcdServer{
		readych:   make(chan struct{}),
		Cfg:       cfg,
		snapCount: cfg.SnapCount,
		errorc:    make(chan error, 1),
		store:     st,
		r: raftNode{
			Node:        n,
			ticker:      time.Tick(time.Duration(cfg.TickMs) * time.Millisecond),
			raftStorage: s,
			storage:     NewStorage(w, ss),
		},
		id:            id,
		attributes:    membership.Attributes{Name: cfg.Name, ClientURLs: cfg.ClientURLs.StringSlice()},
		cluster:       cl,
		stats:         sstats,
		lstats:        lstats,
		SyncTicker:    time.Tick(500 * time.Millisecond),
		peerRt:        prt,
		reqIDGen:      idutil.NewGenerator(uint16(id), time.Now()),
		forceVersionC: make(chan struct{}),
		msgSnapC:      make(chan raftpb.Message, maxInFlightMsgSnap),
	}

	srv.applyV2 = &applierV2store{store: srv.store, cluster: srv.cluster}

	srv.be = be
	srv.lessor = lease.NewLessor(srv.be)
	srv.kv = mvcc.New(srv.be, srv.lessor, &srv.consistIndex)
	srv.consistIndex.setConsistentIndex(srv.kv.ConsistentIndex())
	srv.authStore = auth.NewAuthStore(srv.be)
	if h := cfg.AutoCompactionRetention; h != 0 {
		srv.compactor = compactor.NewPeriodic(h, srv.kv, srv)
		srv.compactor.Run()
	}

	if err = srv.restoreAlarms(); err != nil {
		return nil, err
	}

	// TODO: move transport initialization near the definition of remote
	tr := &rafthttp.Transport{
		TLSInfo:     cfg.PeerTLSInfo,
		DialTimeout: cfg.peerDialTimeout(),
		ID:          id,
		URLs:        cfg.PeerURLs,
		ClusterID:   cl.ID(),
		Raft:        srv,
		Snapshotter: ss,
		ServerStats: sstats,
		LeaderStats: lstats,
		ErrorC:      srv.errorc,
	}
	if err = tr.Start(); err != nil {
		return nil, err
	}
	// add all remotes into transport
	for _, m := range remotes {
		if m.ID != id {
			tr.AddRemote(m.ID, m.PeerURLs)
		}
	}
	for _, m := range cl.Members() {
		if m.ID != id {
			tr.AddPeer(m.ID, m.PeerURLs)
		}
	}
	srv.r.transport = tr

	return srv, nil
}
Beispiel #8
0
// 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)
	}

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

	if err = fileutil.TouchDirAll(cfg.SnapDir()); err != nil {
		plog.Fatalf("create snapshot directory error: %v", err)
	}
	ss := snap.New(cfg.SnapDir())

	bepath := path.Join(cfg.SnapDir(), databaseFilename)
	beExist := fileutil.Exist(bepath)

	var be backend.Backend
	beOpened := make(chan struct{})
	go func() {
		be = backend.NewDefaultBackend(bepath)
		beOpened <- struct{}{}
	}()

	select {
	case <-beOpened:
	case <-time.After(time.Second):
		plog.Warningf("another etcd process is running with the same data dir and holding the file lock.")
		plog.Warningf("waiting for it to exit before starting...")
		<-beOpened
	}

	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
		snapshot *raftpb.Snapshot
	)

	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("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 {
				plog.Panicf("recovered store from snapshot error: %v", err)
			}
			plog.Infof("recovered store from snapshot at index %d", snapshot.Metadata.Index)
		}
		cfg.Print()
		if !cfg.ForceNewCluster {
			id, cl, n, s, w = restartNode(cfg, snapshot)
		} else {
			id, cl, n, s, w = restartAsStandaloneNode(cfg, snapshot)
		}
		cl.SetStore(st)
		cl.SetBackend(be)
		cl.Recover(api.UpdateCapability)
		if cl.Version() != nil && !cl.Version().LessThan(semver.Version{Major: 3}) && !beExist {
			os.RemoveAll(bepath)
			return nil, fmt.Errorf("database file (%v) of the backend is missing", bepath)
		}
	default:
		return nil, fmt.Errorf("unsupported bootstrap config")
	}

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

	sstats := &stats.ServerStats{
		Name: cfg.Name,
		ID:   id.String(),
	}
	sstats.Initialize()
	lstats := stats.NewLeaderStats(id.String())

	heartbeat := time.Duration(cfg.TickMs) * time.Millisecond
	srv = &EtcdServer{
		readych:   make(chan struct{}),
		Cfg:       cfg,
		snapCount: cfg.SnapCount,
		errorc:    make(chan error, 1),
		store:     st,
		r: raftNode{
			isIDRemoved: func(id uint64) bool { return cl.IsIDRemoved(types.ID(id)) },
			Node:        n,
			ticker:      time.Tick(heartbeat),
			// set up contention detectors for raft heartbeat message.
			// expect to send a heartbeat within 2 heartbeat intervals.
			td:          contention.NewTimeoutDetector(2 * heartbeat),
			heartbeat:   heartbeat,
			raftStorage: s,
			storage:     NewStorage(w, ss),
			msgSnapC:    make(chan raftpb.Message, maxInFlightMsgSnap),
			readStateC:  make(chan raft.ReadState, 1),
		},
		id:            id,
		attributes:    membership.Attributes{Name: cfg.Name, ClientURLs: cfg.ClientURLs.StringSlice()},
		cluster:       cl,
		stats:         sstats,
		lstats:        lstats,
		SyncTicker:    time.Tick(500 * time.Millisecond),
		peerRt:        prt,
		reqIDGen:      idutil.NewGenerator(uint16(id), time.Now()),
		forceVersionC: make(chan struct{}),
	}

	srv.applyV2 = &applierV2store{store: srv.store, cluster: srv.cluster}

	srv.be = be
	minTTL := time.Duration((3*cfg.ElectionTicks)/2) * heartbeat

	// always recover lessor before kv. When we recover the mvcc.KV it will reattach keys to its leases.
	// If we recover mvcc.KV first, it will attach the keys to the wrong lessor before it recovers.
	srv.lessor = lease.NewLessor(srv.be, int64(math.Ceil(minTTL.Seconds())))
	srv.kv = mvcc.New(srv.be, srv.lessor, &srv.consistIndex)
	if beExist {
		kvindex := srv.kv.ConsistentIndex()
		// TODO: remove kvindex != 0 checking when we do not expect users to upgrade
		// etcd from pre-3.0 release.
		if snapshot != nil && kvindex < snapshot.Metadata.Index {
			if kvindex != 0 {
				return nil, fmt.Errorf("database file (%v index %d) does not match with snapshot (index %d).", bepath, kvindex, snapshot.Metadata.Index)
			}
			plog.Warningf("consistent index never saved (snapshot index=%d)", snapshot.Metadata.Index)
		}
	}
	srv.consistIndex.setConsistentIndex(srv.kv.ConsistentIndex())

	srv.authStore = auth.NewAuthStore(srv.be)
	if h := cfg.AutoCompactionRetention; h != 0 {
		srv.compactor = compactor.NewPeriodic(h, srv.kv, srv)
		srv.compactor.Run()
	}

	srv.applyV3Base = &applierV3backend{srv}
	if err = srv.restoreAlarms(); err != nil {
		return nil, err
	}

	// TODO: move transport initialization near the definition of remote
	tr := &rafthttp.Transport{
		TLSInfo:     cfg.PeerTLSInfo,
		DialTimeout: cfg.peerDialTimeout(),
		ID:          id,
		URLs:        cfg.PeerURLs,
		ClusterID:   cl.ID(),
		Raft:        srv,
		Snapshotter: ss,
		ServerStats: sstats,
		LeaderStats: lstats,
		ErrorC:      srv.errorc,
	}
	if err = tr.Start(); err != nil {
		return nil, err
	}
	// add all remotes into transport
	for _, m := range remotes {
		if m.ID != id {
			tr.AddRemote(m.ID, m.PeerURLs)
		}
	}
	for _, m := range cl.Members() {
		if m.ID != id {
			tr.AddPeer(m.ID, m.PeerURLs)
		}
	}
	srv.r.transport = tr

	return srv, nil
}
Beispiel #9
0
// makeWAL creates a WAL for the initial cluster
func makeWALAndSnap(waldir, snapdir string, cl *membership.RaftCluster) {
	if err := fileutil.CreateDirAll(waldir); err != nil {
		ExitWithError(ExitIO, err)
	}

	// add members again to persist them to the store we create.
	st := store.New(etcdserver.StoreClusterPrefix, etcdserver.StoreKeysPrefix)
	cl.SetStore(st)
	for _, m := range cl.Members() {
		cl.AddMember(m)
	}

	m := cl.MemberByName(restoreName)
	md := &etcdserverpb.Metadata{NodeID: uint64(m.ID), ClusterID: uint64(cl.ID())}
	metadata, merr := md.Marshal()
	if merr != nil {
		ExitWithError(ExitInvalidInput, merr)
	}

	w, walerr := wal.Create(waldir, metadata)
	if walerr != nil {
		ExitWithError(ExitIO, walerr)
	}
	defer w.Close()

	peers := make([]raft.Peer, len(cl.MemberIDs()))
	for i, id := range cl.MemberIDs() {
		ctx, err := json.Marshal((*cl).Member(id))
		if err != nil {
			ExitWithError(ExitInvalidInput, err)
		}
		peers[i] = raft.Peer{ID: uint64(id), Context: ctx}
	}

	ents := make([]raftpb.Entry, len(peers))
	nodeIDs := make([]uint64, len(peers))
	for i, p := range peers {
		nodeIDs[i] = p.ID
		cc := raftpb.ConfChange{
			Type:    raftpb.ConfChangeAddNode,
			NodeID:  p.ID,
			Context: p.Context}
		d, err := cc.Marshal()
		if err != nil {
			ExitWithError(ExitInvalidInput, err)
		}
		e := raftpb.Entry{
			Type:  raftpb.EntryConfChange,
			Term:  1,
			Index: uint64(i + 1),
			Data:  d,
		}
		ents[i] = e
	}

	commit, term := uint64(len(ents)), uint64(1)

	if err := w.Save(raftpb.HardState{
		Term:   term,
		Vote:   peers[0].ID,
		Commit: commit}, ents); err != nil {
		ExitWithError(ExitIO, err)
	}

	b, berr := st.Save()
	if berr != nil {
		ExitWithError(ExitError, berr)
	}

	raftSnap := raftpb.Snapshot{
		Data: b,
		Metadata: raftpb.SnapshotMetadata{
			Index: commit,
			Term:  term,
			ConfState: raftpb.ConfState{
				Nodes: nodeIDs,
			},
		},
	}
	snapshotter := snap.New(snapdir)
	if err := snapshotter.SaveSnap(raftSnap); err != nil {
		panic(err)
	}

	if err := w.SaveSnapshot(walpb.Snapshot{Index: commit, Term: term}); err != nil {
		ExitWithError(ExitIO, err)
	}
}