diff --git a/vendor/go.etcd.io/etcd/clientv3/retry.go b/vendor/go.etcd.io/etcd/clientv3/retry.go
new file mode 100644
index 0000000..7f89ba6
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/clientv3/retry.go
@@ -0,0 +1,496 @@
+// 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"
+
+	"github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+type retryPolicy uint8
+
+const (
+	repeatable retryPolicy = iota
+	nonRepeatable
+)
+
+type rpcFunc func(ctx context.Context) error
+type retryRPCFunc func(context.Context, rpcFunc, retryPolicy) error
+type retryStopErrFunc func(error) bool
+
+// immutable requests (e.g. Get) should be retried unless it's
+// an obvious server-side error (e.g. rpctypes.ErrRequestTooLarge).
+//
+// "isRepeatableStopError" returns "true" when an immutable request
+// is interrupted by server-side or gRPC-side error and its status
+// code is not transient (!= codes.Unavailable).
+//
+// Returning "true" means retry should stop, since client cannot
+// handle itself even with retries.
+func isRepeatableStopError(err error) bool {
+	eErr := rpctypes.Error(err)
+	// always stop retry on etcd errors
+	if serverErr, ok := eErr.(rpctypes.EtcdError); ok && serverErr.Code() != codes.Unavailable {
+		return true
+	}
+	// only retry if unavailable
+	ev, _ := status.FromError(err)
+	return ev.Code() != codes.Unavailable
+}
+
+// mutable requests (e.g. Put, Delete, Txn) should only be retried
+// when the status code is codes.Unavailable when initial connection
+// has not been established (no pinned endpoint).
+//
+// "isNonRepeatableStopError" returns "true" when a mutable request
+// is interrupted by non-transient error that client cannot handle itself,
+// or transient error while the connection has already been established
+// (pinned endpoint exists).
+//
+// Returning "true" means retry should stop, otherwise it violates
+// write-at-most-once semantics.
+func isNonRepeatableStopError(err error) bool {
+	ev, _ := status.FromError(err)
+	if ev.Code() != codes.Unavailable {
+		return true
+	}
+	desc := rpctypes.ErrorDesc(err)
+	return desc != "there is no address available" && desc != "there is no connection available"
+}
+
+func (c *Client) newRetryWrapper() retryRPCFunc {
+	return func(rpcCtx context.Context, f rpcFunc, rp retryPolicy) error {
+		var isStop retryStopErrFunc
+		switch rp {
+		case repeatable:
+			isStop = isRepeatableStopError
+		case nonRepeatable:
+			isStop = isNonRepeatableStopError
+		}
+		for {
+			if err := readyWait(rpcCtx, c.ctx, c.balancer.ConnectNotify()); err != nil {
+				return err
+			}
+			pinned := c.balancer.pinned()
+			err := f(rpcCtx)
+			if err == nil {
+				return nil
+			}
+			logger.Lvl(4).Infof("clientv3/retry: error %q on pinned endpoint %q", err.Error(), pinned)
+
+			if s, ok := status.FromError(err); ok && (s.Code() == codes.Unavailable || s.Code() == codes.DeadlineExceeded || s.Code() == codes.Internal) {
+				// mark this before endpoint switch is triggered
+				c.balancer.hostPortError(pinned, err)
+				c.balancer.next()
+				logger.Lvl(4).Infof("clientv3/retry: switching from %q due to error %q", pinned, err.Error())
+			}
+
+			if isStop(err) {
+				return err
+			}
+		}
+	}
+}
+
+func (c *Client) newAuthRetryWrapper(retryf retryRPCFunc) retryRPCFunc {
+	return func(rpcCtx context.Context, f rpcFunc, rp retryPolicy) error {
+		for {
+			pinned := c.balancer.pinned()
+			err := retryf(rpcCtx, f, rp)
+			if err == nil {
+				return nil
+			}
+			logger.Lvl(4).Infof("clientv3/auth-retry: error %q on pinned endpoint %q", err.Error(), pinned)
+			// always stop retry on etcd errors other than invalid auth token
+			if rpctypes.Error(err) == rpctypes.ErrInvalidAuthToken {
+				gterr := c.getToken(rpcCtx)
+				if gterr != nil {
+					logger.Lvl(4).Infof("clientv3/auth-retry: cannot retry due to error %q(%q) on pinned endpoint %q", err.Error(), gterr.Error(), pinned)
+					return err // return the original error for simplicity
+				}
+				continue
+			}
+			return err
+		}
+	}
+}
+
+type retryKVClient struct {
+	kc     pb.KVClient
+	retryf retryRPCFunc
+}
+
+// RetryKVClient implements a KVClient.
+func RetryKVClient(c *Client) pb.KVClient {
+	return &retryKVClient{
+		kc:     pb.NewKVClient(c.conn),
+		retryf: c.newAuthRetryWrapper(c.newRetryWrapper()),
+	}
+}
+func (rkv *retryKVClient) Range(ctx context.Context, in *pb.RangeRequest, opts ...grpc.CallOption) (resp *pb.RangeResponse, err error) {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rkv.kc.Range(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rkv *retryKVClient) Put(ctx context.Context, in *pb.PutRequest, opts ...grpc.CallOption) (resp *pb.PutResponse, err error) {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rkv.kc.Put(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rkv *retryKVClient) DeleteRange(ctx context.Context, in *pb.DeleteRangeRequest, opts ...grpc.CallOption) (resp *pb.DeleteRangeResponse, err error) {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rkv.kc.DeleteRange(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rkv *retryKVClient) Txn(ctx context.Context, in *pb.TxnRequest, opts ...grpc.CallOption) (resp *pb.TxnResponse, err error) {
+	// TODO: "repeatable" for read-only txn
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rkv.kc.Txn(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rkv *retryKVClient) Compact(ctx context.Context, in *pb.CompactionRequest, opts ...grpc.CallOption) (resp *pb.CompactionResponse, err error) {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rkv.kc.Compact(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+type retryLeaseClient struct {
+	lc     pb.LeaseClient
+	retryf retryRPCFunc
+}
+
+// RetryLeaseClient implements a LeaseClient.
+func RetryLeaseClient(c *Client) pb.LeaseClient {
+	return &retryLeaseClient{
+		lc:     pb.NewLeaseClient(c.conn),
+		retryf: c.newAuthRetryWrapper(c.newRetryWrapper()),
+	}
+}
+
+func (rlc *retryLeaseClient) LeaseTimeToLive(ctx context.Context, in *pb.LeaseTimeToLiveRequest, opts ...grpc.CallOption) (resp *pb.LeaseTimeToLiveResponse, err error) {
+	err = rlc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rlc.lc.LeaseTimeToLive(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rlc *retryLeaseClient) LeaseLeases(ctx context.Context, in *pb.LeaseLeasesRequest, opts ...grpc.CallOption) (resp *pb.LeaseLeasesResponse, err error) {
+	err = rlc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rlc.lc.LeaseLeases(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rlc *retryLeaseClient) LeaseGrant(ctx context.Context, in *pb.LeaseGrantRequest, opts ...grpc.CallOption) (resp *pb.LeaseGrantResponse, err error) {
+	err = rlc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rlc.lc.LeaseGrant(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+
+}
+
+func (rlc *retryLeaseClient) LeaseRevoke(ctx context.Context, in *pb.LeaseRevokeRequest, opts ...grpc.CallOption) (resp *pb.LeaseRevokeResponse, err error) {
+	err = rlc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rlc.lc.LeaseRevoke(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rlc *retryLeaseClient) LeaseKeepAlive(ctx context.Context, opts ...grpc.CallOption) (stream pb.Lease_LeaseKeepAliveClient, err error) {
+	err = rlc.retryf(ctx, func(rctx context.Context) error {
+		stream, err = rlc.lc.LeaseKeepAlive(rctx, opts...)
+		return err
+	}, repeatable)
+	return stream, err
+}
+
+type retryClusterClient struct {
+	cc     pb.ClusterClient
+	retryf retryRPCFunc
+}
+
+// RetryClusterClient implements a ClusterClient.
+func RetryClusterClient(c *Client) pb.ClusterClient {
+	return &retryClusterClient{
+		cc:     pb.NewClusterClient(c.conn),
+		retryf: c.newRetryWrapper(),
+	}
+}
+
+func (rcc *retryClusterClient) MemberList(ctx context.Context, in *pb.MemberListRequest, opts ...grpc.CallOption) (resp *pb.MemberListResponse, err error) {
+	err = rcc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rcc.cc.MemberList(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rcc *retryClusterClient) MemberAdd(ctx context.Context, in *pb.MemberAddRequest, opts ...grpc.CallOption) (resp *pb.MemberAddResponse, err error) {
+	err = rcc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rcc.cc.MemberAdd(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rcc *retryClusterClient) MemberRemove(ctx context.Context, in *pb.MemberRemoveRequest, opts ...grpc.CallOption) (resp *pb.MemberRemoveResponse, err error) {
+	err = rcc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rcc.cc.MemberRemove(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rcc *retryClusterClient) MemberUpdate(ctx context.Context, in *pb.MemberUpdateRequest, opts ...grpc.CallOption) (resp *pb.MemberUpdateResponse, err error) {
+	err = rcc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rcc.cc.MemberUpdate(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+type retryMaintenanceClient struct {
+	mc     pb.MaintenanceClient
+	retryf retryRPCFunc
+}
+
+// RetryMaintenanceClient implements a Maintenance.
+func RetryMaintenanceClient(c *Client, conn *grpc.ClientConn) pb.MaintenanceClient {
+	return &retryMaintenanceClient{
+		mc:     pb.NewMaintenanceClient(conn),
+		retryf: c.newRetryWrapper(),
+	}
+}
+
+func (rmc *retryMaintenanceClient) Alarm(ctx context.Context, in *pb.AlarmRequest, opts ...grpc.CallOption) (resp *pb.AlarmResponse, err error) {
+	err = rmc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rmc.mc.Alarm(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rmc *retryMaintenanceClient) Status(ctx context.Context, in *pb.StatusRequest, opts ...grpc.CallOption) (resp *pb.StatusResponse, err error) {
+	err = rmc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rmc.mc.Status(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rmc *retryMaintenanceClient) Hash(ctx context.Context, in *pb.HashRequest, opts ...grpc.CallOption) (resp *pb.HashResponse, err error) {
+	err = rmc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rmc.mc.Hash(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rmc *retryMaintenanceClient) HashKV(ctx context.Context, in *pb.HashKVRequest, opts ...grpc.CallOption) (resp *pb.HashKVResponse, err error) {
+	err = rmc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rmc.mc.HashKV(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rmc *retryMaintenanceClient) Snapshot(ctx context.Context, in *pb.SnapshotRequest, opts ...grpc.CallOption) (stream pb.Maintenance_SnapshotClient, err error) {
+	err = rmc.retryf(ctx, func(rctx context.Context) error {
+		stream, err = rmc.mc.Snapshot(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return stream, err
+}
+
+func (rmc *retryMaintenanceClient) MoveLeader(ctx context.Context, in *pb.MoveLeaderRequest, opts ...grpc.CallOption) (resp *pb.MoveLeaderResponse, err error) {
+	err = rmc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rmc.mc.MoveLeader(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rmc *retryMaintenanceClient) Defragment(ctx context.Context, in *pb.DefragmentRequest, opts ...grpc.CallOption) (resp *pb.DefragmentResponse, err error) {
+	err = rmc.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rmc.mc.Defragment(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+type retryAuthClient struct {
+	ac     pb.AuthClient
+	retryf retryRPCFunc
+}
+
+// RetryAuthClient implements a AuthClient.
+func RetryAuthClient(c *Client) pb.AuthClient {
+	return &retryAuthClient{
+		ac:     pb.NewAuthClient(c.conn),
+		retryf: c.newRetryWrapper(),
+	}
+}
+
+func (rac *retryAuthClient) UserList(ctx context.Context, in *pb.AuthUserListRequest, opts ...grpc.CallOption) (resp *pb.AuthUserListResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.UserList(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) UserGet(ctx context.Context, in *pb.AuthUserGetRequest, opts ...grpc.CallOption) (resp *pb.AuthUserGetResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.UserGet(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) RoleGet(ctx context.Context, in *pb.AuthRoleGetRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleGetResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.RoleGet(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) RoleList(ctx context.Context, in *pb.AuthRoleListRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleListResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.RoleList(rctx, in, opts...)
+		return err
+	}, repeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) AuthEnable(ctx context.Context, in *pb.AuthEnableRequest, opts ...grpc.CallOption) (resp *pb.AuthEnableResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.AuthEnable(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) AuthDisable(ctx context.Context, in *pb.AuthDisableRequest, opts ...grpc.CallOption) (resp *pb.AuthDisableResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.AuthDisable(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) UserAdd(ctx context.Context, in *pb.AuthUserAddRequest, opts ...grpc.CallOption) (resp *pb.AuthUserAddResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.UserAdd(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) UserDelete(ctx context.Context, in *pb.AuthUserDeleteRequest, opts ...grpc.CallOption) (resp *pb.AuthUserDeleteResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.UserDelete(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) UserChangePassword(ctx context.Context, in *pb.AuthUserChangePasswordRequest, opts ...grpc.CallOption) (resp *pb.AuthUserChangePasswordResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.UserChangePassword(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) UserGrantRole(ctx context.Context, in *pb.AuthUserGrantRoleRequest, opts ...grpc.CallOption) (resp *pb.AuthUserGrantRoleResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.UserGrantRole(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) UserRevokeRole(ctx context.Context, in *pb.AuthUserRevokeRoleRequest, opts ...grpc.CallOption) (resp *pb.AuthUserRevokeRoleResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.UserRevokeRole(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) RoleAdd(ctx context.Context, in *pb.AuthRoleAddRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleAddResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.RoleAdd(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) RoleDelete(ctx context.Context, in *pb.AuthRoleDeleteRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleDeleteResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.RoleDelete(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) RoleGrantPermission(ctx context.Context, in *pb.AuthRoleGrantPermissionRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleGrantPermissionResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.RoleGrantPermission(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) RoleRevokePermission(ctx context.Context, in *pb.AuthRoleRevokePermissionRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleRevokePermissionResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.RoleRevokePermission(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}
+
+func (rac *retryAuthClient) Authenticate(ctx context.Context, in *pb.AuthenticateRequest, opts ...grpc.CallOption) (resp *pb.AuthenticateResponse, err error) {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
+		resp, err = rac.ac.Authenticate(rctx, in, opts...)
+		return err
+	}, nonRepeatable)
+	return resp, err
+}