diff --git a/vendor/github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes/error.go b/vendor/github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes/error.go
new file mode 100644
index 0000000..bc1ad7b
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes/error.go
@@ -0,0 +1,217 @@
+// Copyright 2015 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 rpctypes
+
+import (
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+// server-side error
+var (
+	ErrGRPCEmptyKey      = status.New(codes.InvalidArgument, "etcdserver: key is not provided").Err()
+	ErrGRPCKeyNotFound   = status.New(codes.InvalidArgument, "etcdserver: key not found").Err()
+	ErrGRPCValueProvided = status.New(codes.InvalidArgument, "etcdserver: value is provided").Err()
+	ErrGRPCLeaseProvided = status.New(codes.InvalidArgument, "etcdserver: lease is provided").Err()
+	ErrGRPCTooManyOps    = status.New(codes.InvalidArgument, "etcdserver: too many operations in txn request").Err()
+	ErrGRPCDuplicateKey  = status.New(codes.InvalidArgument, "etcdserver: duplicate key given in txn request").Err()
+	ErrGRPCCompacted     = status.New(codes.OutOfRange, "etcdserver: mvcc: required revision has been compacted").Err()
+	ErrGRPCFutureRev     = status.New(codes.OutOfRange, "etcdserver: mvcc: required revision is a future revision").Err()
+	ErrGRPCNoSpace       = status.New(codes.ResourceExhausted, "etcdserver: mvcc: database space exceeded").Err()
+
+	ErrGRPCLeaseNotFound    = status.New(codes.NotFound, "etcdserver: requested lease not found").Err()
+	ErrGRPCLeaseExist       = status.New(codes.FailedPrecondition, "etcdserver: lease already exists").Err()
+	ErrGRPCLeaseTTLTooLarge = status.New(codes.OutOfRange, "etcdserver: too large lease TTL").Err()
+
+	ErrGRPCMemberExist            = status.New(codes.FailedPrecondition, "etcdserver: member ID already exist").Err()
+	ErrGRPCPeerURLExist           = status.New(codes.FailedPrecondition, "etcdserver: Peer URLs already exists").Err()
+	ErrGRPCMemberNotEnoughStarted = status.New(codes.FailedPrecondition, "etcdserver: re-configuration failed due to not enough started members").Err()
+	ErrGRPCMemberBadURLs          = status.New(codes.InvalidArgument, "etcdserver: given member URLs are invalid").Err()
+	ErrGRPCMemberNotFound         = status.New(codes.NotFound, "etcdserver: member not found").Err()
+
+	ErrGRPCRequestTooLarge        = status.New(codes.InvalidArgument, "etcdserver: request is too large").Err()
+	ErrGRPCRequestTooManyRequests = status.New(codes.ResourceExhausted, "etcdserver: too many requests").Err()
+
+	ErrGRPCRootUserNotExist     = status.New(codes.FailedPrecondition, "etcdserver: root user does not exist").Err()
+	ErrGRPCRootRoleNotExist     = status.New(codes.FailedPrecondition, "etcdserver: root user does not have root role").Err()
+	ErrGRPCUserAlreadyExist     = status.New(codes.FailedPrecondition, "etcdserver: user name already exists").Err()
+	ErrGRPCUserEmpty            = status.New(codes.InvalidArgument, "etcdserver: user name is empty").Err()
+	ErrGRPCUserNotFound         = status.New(codes.FailedPrecondition, "etcdserver: user name not found").Err()
+	ErrGRPCRoleAlreadyExist     = status.New(codes.FailedPrecondition, "etcdserver: role name already exists").Err()
+	ErrGRPCRoleNotFound         = status.New(codes.FailedPrecondition, "etcdserver: role name not found").Err()
+	ErrGRPCAuthFailed           = status.New(codes.InvalidArgument, "etcdserver: authentication failed, invalid user ID or password").Err()
+	ErrGRPCPermissionDenied     = status.New(codes.PermissionDenied, "etcdserver: permission denied").Err()
+	ErrGRPCRoleNotGranted       = status.New(codes.FailedPrecondition, "etcdserver: role is not granted to the user").Err()
+	ErrGRPCPermissionNotGranted = status.New(codes.FailedPrecondition, "etcdserver: permission is not granted to the role").Err()
+	ErrGRPCAuthNotEnabled       = status.New(codes.FailedPrecondition, "etcdserver: authentication is not enabled").Err()
+	ErrGRPCInvalidAuthToken     = status.New(codes.Unauthenticated, "etcdserver: invalid auth token").Err()
+	ErrGRPCInvalidAuthMgmt      = status.New(codes.InvalidArgument, "etcdserver: invalid auth management").Err()
+
+	ErrGRPCNoLeader                   = status.New(codes.Unavailable, "etcdserver: no leader").Err()
+	ErrGRPCNotLeader                  = status.New(codes.FailedPrecondition, "etcdserver: not leader").Err()
+	ErrGRPCLeaderChanged              = status.New(codes.Unavailable, "etcdserver: leader changed").Err()
+	ErrGRPCNotCapable                 = status.New(codes.Unavailable, "etcdserver: not capable").Err()
+	ErrGRPCStopped                    = status.New(codes.Unavailable, "etcdserver: server stopped").Err()
+	ErrGRPCTimeout                    = status.New(codes.Unavailable, "etcdserver: request timed out").Err()
+	ErrGRPCTimeoutDueToLeaderFail     = status.New(codes.Unavailable, "etcdserver: request timed out, possibly due to previous leader failure").Err()
+	ErrGRPCTimeoutDueToConnectionLost = status.New(codes.Unavailable, "etcdserver: request timed out, possibly due to connection lost").Err()
+	ErrGRPCUnhealthy                  = status.New(codes.Unavailable, "etcdserver: unhealthy cluster").Err()
+	ErrGRPCCorrupt                    = status.New(codes.DataLoss, "etcdserver: corrupt cluster").Err()
+
+	errStringToError = map[string]error{
+		ErrorDesc(ErrGRPCEmptyKey):      ErrGRPCEmptyKey,
+		ErrorDesc(ErrGRPCKeyNotFound):   ErrGRPCKeyNotFound,
+		ErrorDesc(ErrGRPCValueProvided): ErrGRPCValueProvided,
+		ErrorDesc(ErrGRPCLeaseProvided): ErrGRPCLeaseProvided,
+
+		ErrorDesc(ErrGRPCTooManyOps):   ErrGRPCTooManyOps,
+		ErrorDesc(ErrGRPCDuplicateKey): ErrGRPCDuplicateKey,
+		ErrorDesc(ErrGRPCCompacted):    ErrGRPCCompacted,
+		ErrorDesc(ErrGRPCFutureRev):    ErrGRPCFutureRev,
+		ErrorDesc(ErrGRPCNoSpace):      ErrGRPCNoSpace,
+
+		ErrorDesc(ErrGRPCLeaseNotFound):    ErrGRPCLeaseNotFound,
+		ErrorDesc(ErrGRPCLeaseExist):       ErrGRPCLeaseExist,
+		ErrorDesc(ErrGRPCLeaseTTLTooLarge): ErrGRPCLeaseTTLTooLarge,
+
+		ErrorDesc(ErrGRPCMemberExist):            ErrGRPCMemberExist,
+		ErrorDesc(ErrGRPCPeerURLExist):           ErrGRPCPeerURLExist,
+		ErrorDesc(ErrGRPCMemberNotEnoughStarted): ErrGRPCMemberNotEnoughStarted,
+		ErrorDesc(ErrGRPCMemberBadURLs):          ErrGRPCMemberBadURLs,
+		ErrorDesc(ErrGRPCMemberNotFound):         ErrGRPCMemberNotFound,
+
+		ErrorDesc(ErrGRPCRequestTooLarge):        ErrGRPCRequestTooLarge,
+		ErrorDesc(ErrGRPCRequestTooManyRequests): ErrGRPCRequestTooManyRequests,
+
+		ErrorDesc(ErrGRPCRootUserNotExist):     ErrGRPCRootUserNotExist,
+		ErrorDesc(ErrGRPCRootRoleNotExist):     ErrGRPCRootRoleNotExist,
+		ErrorDesc(ErrGRPCUserAlreadyExist):     ErrGRPCUserAlreadyExist,
+		ErrorDesc(ErrGRPCUserEmpty):            ErrGRPCUserEmpty,
+		ErrorDesc(ErrGRPCUserNotFound):         ErrGRPCUserNotFound,
+		ErrorDesc(ErrGRPCRoleAlreadyExist):     ErrGRPCRoleAlreadyExist,
+		ErrorDesc(ErrGRPCRoleNotFound):         ErrGRPCRoleNotFound,
+		ErrorDesc(ErrGRPCAuthFailed):           ErrGRPCAuthFailed,
+		ErrorDesc(ErrGRPCPermissionDenied):     ErrGRPCPermissionDenied,
+		ErrorDesc(ErrGRPCRoleNotGranted):       ErrGRPCRoleNotGranted,
+		ErrorDesc(ErrGRPCPermissionNotGranted): ErrGRPCPermissionNotGranted,
+		ErrorDesc(ErrGRPCAuthNotEnabled):       ErrGRPCAuthNotEnabled,
+		ErrorDesc(ErrGRPCInvalidAuthToken):     ErrGRPCInvalidAuthToken,
+		ErrorDesc(ErrGRPCInvalidAuthMgmt):      ErrGRPCInvalidAuthMgmt,
+
+		ErrorDesc(ErrGRPCNoLeader):                   ErrGRPCNoLeader,
+		ErrorDesc(ErrGRPCNotLeader):                  ErrGRPCNotLeader,
+		ErrorDesc(ErrGRPCNotCapable):                 ErrGRPCNotCapable,
+		ErrorDesc(ErrGRPCStopped):                    ErrGRPCStopped,
+		ErrorDesc(ErrGRPCTimeout):                    ErrGRPCTimeout,
+		ErrorDesc(ErrGRPCTimeoutDueToLeaderFail):     ErrGRPCTimeoutDueToLeaderFail,
+		ErrorDesc(ErrGRPCTimeoutDueToConnectionLost): ErrGRPCTimeoutDueToConnectionLost,
+		ErrorDesc(ErrGRPCUnhealthy):                  ErrGRPCUnhealthy,
+		ErrorDesc(ErrGRPCCorrupt):                    ErrGRPCCorrupt,
+	}
+)
+
+// client-side error
+var (
+	ErrEmptyKey      = Error(ErrGRPCEmptyKey)
+	ErrKeyNotFound   = Error(ErrGRPCKeyNotFound)
+	ErrValueProvided = Error(ErrGRPCValueProvided)
+	ErrLeaseProvided = Error(ErrGRPCLeaseProvided)
+	ErrTooManyOps    = Error(ErrGRPCTooManyOps)
+	ErrDuplicateKey  = Error(ErrGRPCDuplicateKey)
+	ErrCompacted     = Error(ErrGRPCCompacted)
+	ErrFutureRev     = Error(ErrGRPCFutureRev)
+	ErrNoSpace       = Error(ErrGRPCNoSpace)
+
+	ErrLeaseNotFound    = Error(ErrGRPCLeaseNotFound)
+	ErrLeaseExist       = Error(ErrGRPCLeaseExist)
+	ErrLeaseTTLTooLarge = Error(ErrGRPCLeaseTTLTooLarge)
+
+	ErrMemberExist            = Error(ErrGRPCMemberExist)
+	ErrPeerURLExist           = Error(ErrGRPCPeerURLExist)
+	ErrMemberNotEnoughStarted = Error(ErrGRPCMemberNotEnoughStarted)
+	ErrMemberBadURLs          = Error(ErrGRPCMemberBadURLs)
+	ErrMemberNotFound         = Error(ErrGRPCMemberNotFound)
+
+	ErrRequestTooLarge = Error(ErrGRPCRequestTooLarge)
+	ErrTooManyRequests = Error(ErrGRPCRequestTooManyRequests)
+
+	ErrRootUserNotExist     = Error(ErrGRPCRootUserNotExist)
+	ErrRootRoleNotExist     = Error(ErrGRPCRootRoleNotExist)
+	ErrUserAlreadyExist     = Error(ErrGRPCUserAlreadyExist)
+	ErrUserEmpty            = Error(ErrGRPCUserEmpty)
+	ErrUserNotFound         = Error(ErrGRPCUserNotFound)
+	ErrRoleAlreadyExist     = Error(ErrGRPCRoleAlreadyExist)
+	ErrRoleNotFound         = Error(ErrGRPCRoleNotFound)
+	ErrAuthFailed           = Error(ErrGRPCAuthFailed)
+	ErrPermissionDenied     = Error(ErrGRPCPermissionDenied)
+	ErrRoleNotGranted       = Error(ErrGRPCRoleNotGranted)
+	ErrPermissionNotGranted = Error(ErrGRPCPermissionNotGranted)
+	ErrAuthNotEnabled       = Error(ErrGRPCAuthNotEnabled)
+	ErrInvalidAuthToken     = Error(ErrGRPCInvalidAuthToken)
+	ErrInvalidAuthMgmt      = Error(ErrGRPCInvalidAuthMgmt)
+
+	ErrNoLeader                   = Error(ErrGRPCNoLeader)
+	ErrNotLeader                  = Error(ErrGRPCNotLeader)
+	ErrLeaderChanged              = Error(ErrGRPCLeaderChanged)
+	ErrNotCapable                 = Error(ErrGRPCNotCapable)
+	ErrStopped                    = Error(ErrGRPCStopped)
+	ErrTimeout                    = Error(ErrGRPCTimeout)
+	ErrTimeoutDueToLeaderFail     = Error(ErrGRPCTimeoutDueToLeaderFail)
+	ErrTimeoutDueToConnectionLost = Error(ErrGRPCTimeoutDueToConnectionLost)
+	ErrUnhealthy                  = Error(ErrGRPCUnhealthy)
+	ErrCorrupt                    = Error(ErrGRPCCorrupt)
+)
+
+// EtcdError defines gRPC server errors.
+// (https://github.com/grpc/grpc-go/blob/master/rpc_util.go#L319-L323)
+type EtcdError struct {
+	code codes.Code
+	desc string
+}
+
+// Code returns grpc/codes.Code.
+// TODO: define clientv3/codes.Code.
+func (e EtcdError) Code() codes.Code {
+	return e.code
+}
+
+func (e EtcdError) Error() string {
+	return e.desc
+}
+
+func Error(err error) error {
+	if err == nil {
+		return nil
+	}
+	verr, ok := errStringToError[ErrorDesc(err)]
+	if !ok { // not gRPC error
+		return err
+	}
+	ev, ok := status.FromError(verr)
+	var desc string
+	if ok {
+		desc = ev.Message()
+	} else {
+		desc = verr.Error()
+	}
+	return EtcdError{code: ev.Code(), desc: desc}
+}
+
+func ErrorDesc(err error) string {
+	if s, ok := status.FromError(err); ok {
+		return s.Message()
+	}
+	return err.Error()
+}