etcdserver: Extract etcdserver boostrap function

server/etcdserver/server.go

@@ -330,9 +330,7 @@ func (bh *backendHooks) SetConfState(confState *raftpb.ConfState) {
 	bh.confStateDirty = true
 }
 
-// NewServer creates a new EtcdServer from the supplied configuration. The
+func bootstrap(cfg config.ServerConfig) (b *boostrapResult, err error) {
-// configuration is considered static for the lifetime of the EtcdServer.
-func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 	st := v2store.New(StoreClusterPrefix, StoreKeysPrefix)
 
 	var (
@@ -408,7 +406,7 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 		return nil, err
 	}
 	var (
-		remotes  []*membership.Member
+		remotes []*membership.Member
 	)
 
 	switch {
@@ -531,7 +529,7 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 			if beExist {
 				// TODO: remove kvindex != 0 checking when we do not expect users to upgrade
 				// etcd from pre-3.0 release.
-				if  kvindex < snapshot.Metadata.Index {
+				if 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)
 					}
@@ -566,9 +564,53 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 	if terr := fileutil.TouchDirAll(cfg.MemberDir()); terr != nil {
 		return nil, fmt.Errorf("cannot access member directory: %v", terr)
 	}
+	return &boostrapResult{
+		cl:      cl,
+		remotes: remotes,
+		w:       w,
+		n:       n,
+		s:       s,
+		id:      id,
+		prt:     prt,
+		ci:      ci,
+		st:      st,
+		be:      be,
+		ss:      ss,
+		beHooks: beHooks,
+	}, nil
+}
 
-	sstats := stats.NewServerStats(cfg.Name, id.String())
+type boostrapResult struct {
-	lstats := stats.NewLeaderStats(cfg.Logger, id.String())
+	cl      *membership.RaftCluster
+	remotes []*membership.Member
+	w       *wal.WAL
+	n       raft.Node
+	s       *raft.MemoryStorage
+	id      types.ID
+	prt     http.RoundTripper
+	ci      cindex.ConsistentIndexer
+	st      v2store.Store
+	be      backend.Backend
+	ss      *snap.Snapshotter
+	beHooks *backendHooks
+}
+
+// NewServer creates a new EtcdServer from the supplied configuration. The
+// configuration is considered static for the lifetime of the EtcdServer.
+func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
+	b, err := bootstrap(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if err != nil {
+			b.be.Close()
+		}
+	}()
+
+	sstats := stats.NewServerStats(cfg.Name, b.id.String())
+	lstats := stats.NewLeaderStats(cfg.Logger, b.id.String())
 
 	heartbeat := time.Duration(cfg.TickMs) * time.Millisecond
 	srv = &EtcdServer{
@@ -577,36 +619,36 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 		lgMu:        new(sync.RWMutex),
 		lg:          cfg.Logger,
 		errorc:      make(chan error, 1),
-		v2store:     st,
+		v2store:     b.st,
-		snapshotter: ss,
+		snapshotter: b.ss,
 		r: *newRaftNode(
 			raftNodeConfig{
 				lg:          cfg.Logger,
-				isIDRemoved: func(id uint64) bool { return cl.IsIDRemoved(types.ID(id)) },
+				isIDRemoved: func(id uint64) bool { return b.cl.IsIDRemoved(types.ID(id)) },
-				Node:        n,
+				Node:        b.n,
 				heartbeat:   heartbeat,
-				raftStorage: s,
+				raftStorage: b.s,
-				storage:     NewStorage(w, ss),
+				storage:     NewStorage(b.w, b.ss),
 			},
 		),
-		id:                 id,
+		id:                 b.id,
 		attributes:         membership.Attributes{Name: cfg.Name, ClientURLs: cfg.ClientURLs.StringSlice()},
-		cluster:            cl,
+		cluster:            b.cl,
 		stats:              sstats,
 		lstats:             lstats,
 		SyncTicker:         time.NewTicker(500 * time.Millisecond),
-		peerRt:             prt,
+		peerRt:             b.prt,
-		reqIDGen:           idutil.NewGenerator(uint16(id), time.Now()),
+		reqIDGen:           idutil.NewGenerator(uint16(b.id), time.Now()),
 		AccessController:   &AccessController{CORS: cfg.CORS, HostWhitelist: cfg.HostWhitelist},
-		consistIndex:       ci,
+		consistIndex:       b.ci,
 		firstCommitInTermC: make(chan struct{}),
 	}
-	serverID.With(prometheus.Labels{"server_id": id.String()}).Set(1)
+	serverID.With(prometheus.Labels{"server_id": b.id.String()}).Set(1)
 
 	srv.applyV2 = NewApplierV2(cfg.Logger, srv.v2store, srv.cluster)
 
-	srv.be = be
+	srv.be = b.be
-	srv.beHooks = beHooks
+	srv.beHooks = b.beHooks
 	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.
@@ -634,7 +676,6 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 	}
 	srv.kv = mvcc.New(srv.Logger(), srv.be, srv.lessor, mvccStoreConfig)
 
-
 	srv.authStore = auth.NewAuthStore(srv.Logger(), srv.be, tp, int(cfg.BcryptCost))
 
 	newSrv := srv // since srv == nil in defer if srv is returned as nil
@@ -671,11 +712,11 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 		Logger:      cfg.Logger,
 		TLSInfo:     cfg.PeerTLSInfo,
 		DialTimeout: cfg.PeerDialTimeout(),
-		ID:          id,
+		ID:          b.id,
 		URLs:        cfg.PeerURLs,
-		ClusterID:   cl.ID(),
+		ClusterID:   b.cl.ID(),
 		Raft:        srv,
-		Snapshotter: ss,
+		Snapshotter: b.ss,
 		ServerStats: sstats,
 		LeaderStats: lstats,
 		ErrorC:      srv.errorc,
@@ -684,13 +725,13 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 		return nil, err
 	}
 	// add all remotes into transport
-	for _, m := range remotes {
+	for _, m := range b.remotes {
-		if m.ID != id {
+		if m.ID != b.id {
 			tr.AddRemote(m.ID, m.PeerURLs)
 		}
 	}
-	for _, m := range cl.Members() {
+	for _, m := range b.cl.Members() {
-		if m.ID != id {
+		if m.ID != b.id {
 			tr.AddPeer(m.ID, m.PeerURLs)
 		}
 	}