diff --git a/vendor/go.etcd.io/etcd/clientv3/lease.go b/vendor/go.etcd.io/etcd/clientv3/lease.go
new file mode 100644
index 0000000..c2796fc
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/clientv3/lease.go
@@ -0,0 +1,596 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package clientv3
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	"go.uber.org/zap"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+type (
+	LeaseRevokeResponse pb.LeaseRevokeResponse
+	LeaseID             int64
+)
+
+// LeaseGrantResponse wraps the protobuf message LeaseGrantResponse.
+type LeaseGrantResponse struct {
+	*pb.ResponseHeader
+	ID    LeaseID
+	TTL   int64
+	Error string
+}
+
+// LeaseKeepAliveResponse wraps the protobuf message LeaseKeepAliveResponse.
+type LeaseKeepAliveResponse struct {
+	*pb.ResponseHeader
+	ID  LeaseID
+	TTL int64
+}
+
+// LeaseTimeToLiveResponse wraps the protobuf message LeaseTimeToLiveResponse.
+type LeaseTimeToLiveResponse struct {
+	*pb.ResponseHeader
+	ID LeaseID `json:"id"`
+
+	// TTL is the remaining TTL in seconds for the lease; the lease will expire in under TTL+1 seconds. Expired lease will return -1.
+	TTL int64 `json:"ttl"`
+
+	// GrantedTTL is the initial granted time in seconds upon lease creation/renewal.
+	GrantedTTL int64 `json:"granted-ttl"`
+
+	// Keys is the list of keys attached to this lease.
+	Keys [][]byte `json:"keys"`
+}
+
+// LeaseStatus represents a lease status.
+type LeaseStatus struct {
+	ID LeaseID `json:"id"`
+	// TODO: TTL int64
+}
+
+// LeaseLeasesResponse wraps the protobuf message LeaseLeasesResponse.
+type LeaseLeasesResponse struct {
+	*pb.ResponseHeader
+	Leases []LeaseStatus `json:"leases"`
+}
+
+const (
+	// defaultTTL is the assumed lease TTL used for the first keepalive
+	// deadline before the actual TTL is known to the client.
+	defaultTTL = 5 * time.Second
+	// NoLease is a lease ID for the absence of a lease.
+	NoLease LeaseID = 0
+
+	// retryConnWait is how long to wait before retrying request due to an error
+	retryConnWait = 500 * time.Millisecond
+)
+
+// LeaseResponseChSize is the size of buffer to store unsent lease responses.
+// WARNING: DO NOT UPDATE.
+// Only for testing purposes.
+var LeaseResponseChSize = 16
+
+// ErrKeepAliveHalted is returned if client keep alive loop halts with an unexpected error.
+//
+// This usually means that automatic lease renewal via KeepAlive is broken, but KeepAliveOnce will still work as expected.
+type ErrKeepAliveHalted struct {
+	Reason error
+}
+
+func (e ErrKeepAliveHalted) Error() string {
+	s := "etcdclient: leases keep alive halted"
+	if e.Reason != nil {
+		s += ": " + e.Reason.Error()
+	}
+	return s
+}
+
+type Lease interface {
+	// Grant creates a new lease.
+	Grant(ctx context.Context, ttl int64) (*LeaseGrantResponse, error)
+
+	// Revoke revokes the given lease.
+	Revoke(ctx context.Context, id LeaseID) (*LeaseRevokeResponse, error)
+
+	// TimeToLive retrieves the lease information of the given lease ID.
+	TimeToLive(ctx context.Context, id LeaseID, opts ...LeaseOption) (*LeaseTimeToLiveResponse, error)
+
+	// Leases retrieves all leases.
+	Leases(ctx context.Context) (*LeaseLeasesResponse, error)
+
+	// KeepAlive attempts to keep the given lease alive forever. If the keepalive responses posted
+	// to the channel are not consumed promptly the channel may become full. When full, the lease
+	// client will continue sending keep alive requests to the etcd server, but will drop responses
+	// until there is capacity on the channel to send more responses.
+	//
+	// If client keep alive loop halts with an unexpected error (e.g. "etcdserver: no leader") or
+	// canceled by the caller (e.g. context.Canceled), KeepAlive returns a ErrKeepAliveHalted error
+	// containing the error reason.
+	//
+	// The returned "LeaseKeepAliveResponse" channel closes if underlying keep
+	// alive stream is interrupted in some way the client cannot handle itself;
+	// given context "ctx" is canceled or timed out.
+	//
+	// TODO(v4.0): post errors to last keep alive message before closing
+	// (see https://github.com/etcd-io/etcd/pull/7866)
+	KeepAlive(ctx context.Context, id LeaseID) (<-chan *LeaseKeepAliveResponse, error)
+
+	// KeepAliveOnce renews the lease once. The response corresponds to the
+	// first message from calling KeepAlive. If the response has a recoverable
+	// error, KeepAliveOnce will retry the RPC with a new keep alive message.
+	//
+	// In most of the cases, Keepalive should be used instead of KeepAliveOnce.
+	KeepAliveOnce(ctx context.Context, id LeaseID) (*LeaseKeepAliveResponse, error)
+
+	// Close releases all resources Lease keeps for efficient communication
+	// with the etcd server.
+	Close() error
+}
+
+type lessor struct {
+	mu sync.Mutex // guards all fields
+
+	// donec is closed and loopErr is set when recvKeepAliveLoop stops
+	donec   chan struct{}
+	loopErr error
+
+	remote pb.LeaseClient
+
+	stream       pb.Lease_LeaseKeepAliveClient
+	streamCancel context.CancelFunc
+
+	stopCtx    context.Context
+	stopCancel context.CancelFunc
+
+	keepAlives map[LeaseID]*keepAlive
+
+	// firstKeepAliveTimeout is the timeout for the first keepalive request
+	// before the actual TTL is known to the lease client
+	firstKeepAliveTimeout time.Duration
+
+	// firstKeepAliveOnce ensures stream starts after first KeepAlive call.
+	firstKeepAliveOnce sync.Once
+
+	callOpts []grpc.CallOption
+
+	lg *zap.Logger
+}
+
+// keepAlive multiplexes a keepalive for a lease over multiple channels
+type keepAlive struct {
+	chs  []chan<- *LeaseKeepAliveResponse
+	ctxs []context.Context
+	// deadline is the time the keep alive channels close if no response
+	deadline time.Time
+	// nextKeepAlive is when to send the next keep alive message
+	nextKeepAlive time.Time
+	// donec is closed on lease revoke, expiration, or cancel.
+	donec chan struct{}
+}
+
+func NewLease(c *Client) Lease {
+	return NewLeaseFromLeaseClient(RetryLeaseClient(c), c, c.cfg.DialTimeout+time.Second)
+}
+
+func NewLeaseFromLeaseClient(remote pb.LeaseClient, c *Client, keepAliveTimeout time.Duration) Lease {
+	l := &lessor{
+		donec:                 make(chan struct{}),
+		keepAlives:            make(map[LeaseID]*keepAlive),
+		remote:                remote,
+		firstKeepAliveTimeout: keepAliveTimeout,
+		lg:                    c.lg,
+	}
+	if l.firstKeepAliveTimeout == time.Second {
+		l.firstKeepAliveTimeout = defaultTTL
+	}
+	if c != nil {
+		l.callOpts = c.callOpts
+	}
+	reqLeaderCtx := WithRequireLeader(context.Background())
+	l.stopCtx, l.stopCancel = context.WithCancel(reqLeaderCtx)
+	return l
+}
+
+func (l *lessor) Grant(ctx context.Context, ttl int64) (*LeaseGrantResponse, error) {
+	r := &pb.LeaseGrantRequest{TTL: ttl}
+	resp, err := l.remote.LeaseGrant(ctx, r, l.callOpts...)
+	if err == nil {
+		gresp := &LeaseGrantResponse{
+			ResponseHeader: resp.GetHeader(),
+			ID:             LeaseID(resp.ID),
+			TTL:            resp.TTL,
+			Error:          resp.Error,
+		}
+		return gresp, nil
+	}
+	return nil, toErr(ctx, err)
+}
+
+func (l *lessor) Revoke(ctx context.Context, id LeaseID) (*LeaseRevokeResponse, error) {
+	r := &pb.LeaseRevokeRequest{ID: int64(id)}
+	resp, err := l.remote.LeaseRevoke(ctx, r, l.callOpts...)
+	if err == nil {
+		return (*LeaseRevokeResponse)(resp), nil
+	}
+	return nil, toErr(ctx, err)
+}
+
+func (l *lessor) TimeToLive(ctx context.Context, id LeaseID, opts ...LeaseOption) (*LeaseTimeToLiveResponse, error) {
+	r := toLeaseTimeToLiveRequest(id, opts...)
+	resp, err := l.remote.LeaseTimeToLive(ctx, r, l.callOpts...)
+	if err == nil {
+		gresp := &LeaseTimeToLiveResponse{
+			ResponseHeader: resp.GetHeader(),
+			ID:             LeaseID(resp.ID),
+			TTL:            resp.TTL,
+			GrantedTTL:     resp.GrantedTTL,
+			Keys:           resp.Keys,
+		}
+		return gresp, nil
+	}
+	return nil, toErr(ctx, err)
+}
+
+func (l *lessor) Leases(ctx context.Context) (*LeaseLeasesResponse, error) {
+	resp, err := l.remote.LeaseLeases(ctx, &pb.LeaseLeasesRequest{}, l.callOpts...)
+	if err == nil {
+		leases := make([]LeaseStatus, len(resp.Leases))
+		for i := range resp.Leases {
+			leases[i] = LeaseStatus{ID: LeaseID(resp.Leases[i].ID)}
+		}
+		return &LeaseLeasesResponse{ResponseHeader: resp.GetHeader(), Leases: leases}, nil
+	}
+	return nil, toErr(ctx, err)
+}
+
+func (l *lessor) KeepAlive(ctx context.Context, id LeaseID) (<-chan *LeaseKeepAliveResponse, error) {
+	ch := make(chan *LeaseKeepAliveResponse, LeaseResponseChSize)
+
+	l.mu.Lock()
+	// ensure that recvKeepAliveLoop is still running
+	select {
+	case <-l.donec:
+		err := l.loopErr
+		l.mu.Unlock()
+		close(ch)
+		return ch, ErrKeepAliveHalted{Reason: err}
+	default:
+	}
+	ka, ok := l.keepAlives[id]
+	if !ok {
+		// create fresh keep alive
+		ka = &keepAlive{
+			chs:           []chan<- *LeaseKeepAliveResponse{ch},
+			ctxs:          []context.Context{ctx},
+			deadline:      time.Now().Add(l.firstKeepAliveTimeout),
+			nextKeepAlive: time.Now(),
+			donec:         make(chan struct{}),
+		}
+		l.keepAlives[id] = ka
+	} else {
+		// add channel and context to existing keep alive
+		ka.ctxs = append(ka.ctxs, ctx)
+		ka.chs = append(ka.chs, ch)
+	}
+	l.mu.Unlock()
+
+	go l.keepAliveCtxCloser(ctx, id, ka.donec)
+	l.firstKeepAliveOnce.Do(func() {
+		go l.recvKeepAliveLoop()
+		go l.deadlineLoop()
+	})
+
+	return ch, nil
+}
+
+func (l *lessor) KeepAliveOnce(ctx context.Context, id LeaseID) (*LeaseKeepAliveResponse, error) {
+	for {
+		resp, err := l.keepAliveOnce(ctx, id)
+		if err == nil {
+			if resp.TTL <= 0 {
+				err = rpctypes.ErrLeaseNotFound
+			}
+			return resp, err
+		}
+		if isHaltErr(ctx, err) {
+			return nil, toErr(ctx, err)
+		}
+	}
+}
+
+func (l *lessor) Close() error {
+	l.stopCancel()
+	// close for synchronous teardown if stream goroutines never launched
+	l.firstKeepAliveOnce.Do(func() { close(l.donec) })
+	<-l.donec
+	return nil
+}
+
+func (l *lessor) keepAliveCtxCloser(ctx context.Context, id LeaseID, donec <-chan struct{}) {
+	select {
+	case <-donec:
+		return
+	case <-l.donec:
+		return
+	case <-ctx.Done():
+	}
+
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	ka, ok := l.keepAlives[id]
+	if !ok {
+		return
+	}
+
+	// close channel and remove context if still associated with keep alive
+	for i, c := range ka.ctxs {
+		if c == ctx {
+			close(ka.chs[i])
+			ka.ctxs = append(ka.ctxs[:i], ka.ctxs[i+1:]...)
+			ka.chs = append(ka.chs[:i], ka.chs[i+1:]...)
+			break
+		}
+	}
+	// remove if no one more listeners
+	if len(ka.chs) == 0 {
+		delete(l.keepAlives, id)
+	}
+}
+
+// closeRequireLeader scans keepAlives for ctxs that have require leader
+// and closes the associated channels.
+func (l *lessor) closeRequireLeader() {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	for _, ka := range l.keepAlives {
+		reqIdxs := 0
+		// find all required leader channels, close, mark as nil
+		for i, ctx := range ka.ctxs {
+			md, ok := metadata.FromOutgoingContext(ctx)
+			if !ok {
+				continue
+			}
+			ks := md[rpctypes.MetadataRequireLeaderKey]
+			if len(ks) < 1 || ks[0] != rpctypes.MetadataHasLeader {
+				continue
+			}
+			close(ka.chs[i])
+			ka.chs[i] = nil
+			reqIdxs++
+		}
+		if reqIdxs == 0 {
+			continue
+		}
+		// remove all channels that required a leader from keepalive
+		newChs := make([]chan<- *LeaseKeepAliveResponse, len(ka.chs)-reqIdxs)
+		newCtxs := make([]context.Context, len(newChs))
+		newIdx := 0
+		for i := range ka.chs {
+			if ka.chs[i] == nil {
+				continue
+			}
+			newChs[newIdx], newCtxs[newIdx] = ka.chs[i], ka.ctxs[newIdx]
+			newIdx++
+		}
+		ka.chs, ka.ctxs = newChs, newCtxs
+	}
+}
+
+func (l *lessor) keepAliveOnce(ctx context.Context, id LeaseID) (*LeaseKeepAliveResponse, error) {
+	cctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	stream, err := l.remote.LeaseKeepAlive(cctx, l.callOpts...)
+	if err != nil {
+		return nil, toErr(ctx, err)
+	}
+
+	err = stream.Send(&pb.LeaseKeepAliveRequest{ID: int64(id)})
+	if err != nil {
+		return nil, toErr(ctx, err)
+	}
+
+	resp, rerr := stream.Recv()
+	if rerr != nil {
+		return nil, toErr(ctx, rerr)
+	}
+
+	karesp := &LeaseKeepAliveResponse{
+		ResponseHeader: resp.GetHeader(),
+		ID:             LeaseID(resp.ID),
+		TTL:            resp.TTL,
+	}
+	return karesp, nil
+}
+
+func (l *lessor) recvKeepAliveLoop() (gerr error) {
+	defer func() {
+		l.mu.Lock()
+		close(l.donec)
+		l.loopErr = gerr
+		for _, ka := range l.keepAlives {
+			ka.close()
+		}
+		l.keepAlives = make(map[LeaseID]*keepAlive)
+		l.mu.Unlock()
+	}()
+
+	for {
+		stream, err := l.resetRecv()
+		if err != nil {
+			if canceledByCaller(l.stopCtx, err) {
+				return err
+			}
+		} else {
+			for {
+				resp, err := stream.Recv()
+				if err != nil {
+					if canceledByCaller(l.stopCtx, err) {
+						return err
+					}
+
+					if toErr(l.stopCtx, err) == rpctypes.ErrNoLeader {
+						l.closeRequireLeader()
+					}
+					break
+				}
+
+				l.recvKeepAlive(resp)
+			}
+		}
+
+		select {
+		case <-time.After(retryConnWait):
+		case <-l.stopCtx.Done():
+			return l.stopCtx.Err()
+		}
+	}
+}
+
+// resetRecv opens a new lease stream and starts sending keep alive requests.
+func (l *lessor) resetRecv() (pb.Lease_LeaseKeepAliveClient, error) {
+	sctx, cancel := context.WithCancel(l.stopCtx)
+	stream, err := l.remote.LeaseKeepAlive(sctx, append(l.callOpts, withMax(0))...)
+	if err != nil {
+		cancel()
+		return nil, err
+	}
+
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.stream != nil && l.streamCancel != nil {
+		l.streamCancel()
+	}
+
+	l.streamCancel = cancel
+	l.stream = stream
+
+	go l.sendKeepAliveLoop(stream)
+	return stream, nil
+}
+
+// recvKeepAlive updates a lease based on its LeaseKeepAliveResponse
+func (l *lessor) recvKeepAlive(resp *pb.LeaseKeepAliveResponse) {
+	karesp := &LeaseKeepAliveResponse{
+		ResponseHeader: resp.GetHeader(),
+		ID:             LeaseID(resp.ID),
+		TTL:            resp.TTL,
+	}
+
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	ka, ok := l.keepAlives[karesp.ID]
+	if !ok {
+		return
+	}
+
+	if karesp.TTL <= 0 {
+		// lease expired; close all keep alive channels
+		delete(l.keepAlives, karesp.ID)
+		ka.close()
+		return
+	}
+
+	// send update to all channels
+	nextKeepAlive := time.Now().Add((time.Duration(karesp.TTL) * time.Second) / 3.0)
+	ka.deadline = time.Now().Add(time.Duration(karesp.TTL) * time.Second)
+	for _, ch := range ka.chs {
+		select {
+		case ch <- karesp:
+		default:
+			if l.lg != nil {
+				l.lg.Warn("lease keepalive response queue is full; dropping response send",
+					zap.Int("queue-size", len(ch)),
+					zap.Int("queue-capacity", cap(ch)),
+				)
+			}
+		}
+		// still advance in order to rate-limit keep-alive sends
+		ka.nextKeepAlive = nextKeepAlive
+	}
+}
+
+// deadlineLoop reaps any keep alive channels that have not received a response
+// within the lease TTL
+func (l *lessor) deadlineLoop() {
+	for {
+		select {
+		case <-time.After(time.Second):
+		case <-l.donec:
+			return
+		}
+		now := time.Now()
+		l.mu.Lock()
+		for id, ka := range l.keepAlives {
+			if ka.deadline.Before(now) {
+				// waited too long for response; lease may be expired
+				ka.close()
+				delete(l.keepAlives, id)
+			}
+		}
+		l.mu.Unlock()
+	}
+}
+
+// sendKeepAliveLoop sends keep alive requests for the lifetime of the given stream.
+func (l *lessor) sendKeepAliveLoop(stream pb.Lease_LeaseKeepAliveClient) {
+	for {
+		var tosend []LeaseID
+
+		now := time.Now()
+		l.mu.Lock()
+		for id, ka := range l.keepAlives {
+			if ka.nextKeepAlive.Before(now) {
+				tosend = append(tosend, id)
+			}
+		}
+		l.mu.Unlock()
+
+		for _, id := range tosend {
+			r := &pb.LeaseKeepAliveRequest{ID: int64(id)}
+			if err := stream.Send(r); err != nil {
+				// TODO do something with this error?
+				return
+			}
+		}
+
+		select {
+		case <-time.After(retryConnWait):
+		case <-stream.Context().Done():
+			return
+		case <-l.donec:
+			return
+		case <-l.stopCtx.Done():
+			return
+		}
+	}
+}
+
+func (ka *keepAlive) close() {
+	close(ka.donec)
+	for _, ch := range ka.chs {
+		close(ch)
+	}
+}