diff --git a/vendor/github.com/coreos/etcd/clientv3/compare.go b/vendor/github.com/coreos/etcd/clientv3/compare.go
new file mode 100644
index 0000000..b5f0a25
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/compare.go
@@ -0,0 +1,140 @@
+// 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 (
+	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
+)
+
+type CompareTarget int
+type CompareResult int
+
+const (
+	CompareVersion CompareTarget = iota
+	CompareCreated
+	CompareModified
+	CompareValue
+)
+
+type Cmp pb.Compare
+
+func Compare(cmp Cmp, result string, v interface{}) Cmp {
+	var r pb.Compare_CompareResult
+
+	switch result {
+	case "=":
+		r = pb.Compare_EQUAL
+	case "!=":
+		r = pb.Compare_NOT_EQUAL
+	case ">":
+		r = pb.Compare_GREATER
+	case "<":
+		r = pb.Compare_LESS
+	default:
+		panic("Unknown result op")
+	}
+
+	cmp.Result = r
+	switch cmp.Target {
+	case pb.Compare_VALUE:
+		val, ok := v.(string)
+		if !ok {
+			panic("bad compare value")
+		}
+		cmp.TargetUnion = &pb.Compare_Value{Value: []byte(val)}
+	case pb.Compare_VERSION:
+		cmp.TargetUnion = &pb.Compare_Version{Version: mustInt64(v)}
+	case pb.Compare_CREATE:
+		cmp.TargetUnion = &pb.Compare_CreateRevision{CreateRevision: mustInt64(v)}
+	case pb.Compare_MOD:
+		cmp.TargetUnion = &pb.Compare_ModRevision{ModRevision: mustInt64(v)}
+	case pb.Compare_LEASE:
+		cmp.TargetUnion = &pb.Compare_Lease{Lease: mustInt64orLeaseID(v)}
+	default:
+		panic("Unknown compare type")
+	}
+	return cmp
+}
+
+func Value(key string) Cmp {
+	return Cmp{Key: []byte(key), Target: pb.Compare_VALUE}
+}
+
+func Version(key string) Cmp {
+	return Cmp{Key: []byte(key), Target: pb.Compare_VERSION}
+}
+
+func CreateRevision(key string) Cmp {
+	return Cmp{Key: []byte(key), Target: pb.Compare_CREATE}
+}
+
+func ModRevision(key string) Cmp {
+	return Cmp{Key: []byte(key), Target: pb.Compare_MOD}
+}
+
+// LeaseValue compares a key's LeaseID to a value of your choosing. The empty
+// LeaseID is 0, otherwise known as `NoLease`.
+func LeaseValue(key string) Cmp {
+	return Cmp{Key: []byte(key), Target: pb.Compare_LEASE}
+}
+
+// KeyBytes returns the byte slice holding with the comparison key.
+func (cmp *Cmp) KeyBytes() []byte { return cmp.Key }
+
+// WithKeyBytes sets the byte slice for the comparison key.
+func (cmp *Cmp) WithKeyBytes(key []byte) { cmp.Key = key }
+
+// ValueBytes returns the byte slice holding the comparison value, if any.
+func (cmp *Cmp) ValueBytes() []byte {
+	if tu, ok := cmp.TargetUnion.(*pb.Compare_Value); ok {
+		return tu.Value
+	}
+	return nil
+}
+
+// WithValueBytes sets the byte slice for the comparison's value.
+func (cmp *Cmp) WithValueBytes(v []byte) { cmp.TargetUnion.(*pb.Compare_Value).Value = v }
+
+// WithRange sets the comparison to scan the range [key, end).
+func (cmp Cmp) WithRange(end string) Cmp {
+	cmp.RangeEnd = []byte(end)
+	return cmp
+}
+
+// WithPrefix sets the comparison to scan all keys prefixed by the key.
+func (cmp Cmp) WithPrefix() Cmp {
+	cmp.RangeEnd = getPrefix(cmp.Key)
+	return cmp
+}
+
+// mustInt64 panics if val isn't an int or int64. It returns an int64 otherwise.
+func mustInt64(val interface{}) int64 {
+	if v, ok := val.(int64); ok {
+		return v
+	}
+	if v, ok := val.(int); ok {
+		return int64(v)
+	}
+	panic("bad value")
+}
+
+// mustInt64orLeaseID panics if val isn't a LeaseID, int or int64. It returns an
+// int64 otherwise.
+func mustInt64orLeaseID(val interface{}) int64 {
+	if v, ok := val.(LeaseID); ok {
+		return int64(v)
+	}
+	return mustInt64(val)
+}