Update libkv in godeps

Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>

libnetwork/Godeps/Godeps.json

@@ -205,27 +205,33 @@
 		},
 		{
 			"ImportPath": "github.com/docker/libkv",
-			"Rev": "c2aac5dbbaa5c872211edea7c0f32b3bd67e7410"
+			"Comment": "v0.1.0-35-g7283ef2",
+			"Rev": "7283ef27ed32fe267388510a91709b307bb9942c"
 		},
 		{
 			"ImportPath": "github.com/docker/libkv/store",
-			"Rev": "c2aac5dbbaa5c872211edea7c0f32b3bd67e7410"
+			"Comment": "v0.1.0-35-g7283ef2",
+			"Rev": "7283ef27ed32fe267388510a91709b307bb9942c"
 		},
 		{
 			"ImportPath": "github.com/docker/libkv/store/boltdb",
-			"Rev": "c2aac5dbbaa5c872211edea7c0f32b3bd67e7410"
+			"Comment": "v0.1.0-35-g7283ef2",
+			"Rev": "7283ef27ed32fe267388510a91709b307bb9942c"
 		},
 		{
 			"ImportPath": "github.com/docker/libkv/store/consul",
-			"Rev": "c2aac5dbbaa5c872211edea7c0f32b3bd67e7410"
+			"Comment": "v0.1.0-35-g7283ef2",
+			"Rev": "7283ef27ed32fe267388510a91709b307bb9942c"
 		},
 		{
 			"ImportPath": "github.com/docker/libkv/store/etcd",
-			"Rev": "c2aac5dbbaa5c872211edea7c0f32b3bd67e7410"
+			"Comment": "v0.1.0-35-g7283ef2",
+			"Rev": "7283ef27ed32fe267388510a91709b307bb9942c"
 		},
 		{
 			"ImportPath": "github.com/docker/libkv/store/zookeeper",
-			"Rev": "c2aac5dbbaa5c872211edea7c0f32b3bd67e7410"
+			"Comment": "v0.1.0-35-g7283ef2",
+			"Rev": "7283ef27ed32fe267388510a91709b307bb9942c"
 		},
 		{
 			"ImportPath": "github.com/godbus/dbus",

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/.travis.yml

@@ -1,9 +1,7 @@
 language: go
 
 go:
-  - 1.3
-#  - 1.4
-# see https://github.com/moovweb/gvm/pull/116 for why Go 1.4 is currently disabled
+  - 1.5.3
 
 # let us have speedy Docker-based Travis workers
 sudo: false
@@ -11,19 +9,18 @@ sudo: false
 before_install:
   # Symlink below is needed for Travis CI to work correctly on personal forks of libkv
   - ln -s $HOME/gopath/src/github.com/${TRAVIS_REPO_SLUG///libkv/} $HOME/gopath/src/github.com/docker
-  - go get golang.org/x/tools/cmd/vet
   - go get golang.org/x/tools/cmd/cover
   - go get github.com/mattn/goveralls
   - go get github.com/golang/lint/golint
   - go get github.com/GeertJohan/fgt
 
 before_script:
-  - script/travis_consul.sh 0.5.2 
-  - script/travis_etcd.sh 2.2.0
-  - script/travis_zk.sh 3.4.6
+  - script/travis_consul.sh 0.6.3
+  - script/travis_etcd.sh 2.2.5
+  - script/travis_zk.sh 3.5.1-alpha
 
 script:
-  - ./consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul -config-file=./config.json 1>/dev/null &
+  - ./consul agent -server -bootstrap -advertise=127.0.0.1 -data-dir /tmp/consul -config-file=./config.json 1>/dev/null &
   - ./etcd/etcd --listen-client-urls 'http://0.0.0.0:4001' --advertise-client-urls 'http://127.0.0.1:4001' >/dev/null 2>&1 &
   - ./zk/bin/zkServer.sh start ./zk/conf/zoo.cfg 1> /dev/null
   - script/validate-gofmt

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/LICENSE.code

@@ -176,7 +176,7 @@
 
    END OF TERMS AND CONDITIONS
 
-   Copyright 2014-2015 Docker, Inc.
+   Copyright 2014-2016 Docker, Inc.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/MAINTAINERS

@@ -0,0 +1,46 @@
+# Libkv maintainers file
+#
+# This file describes who runs the docker/libkv project and how.
+# This is a living document - if you see something out of date or missing, speak up!
+#
+# It is structured to be consumable by both humans and programs.
+# To extract its contents programmatically, use any TOML-compliant parser.
+#
+# This file is compiled into the MAINTAINERS file in docker/opensource.
+#
+[Org]
+	[Org."Core maintainers"]
+		people = [
+			"abronan",
+			"aluzzardi",
+			"sanimej",
+			"vieux",
+		]
+
+[people]
+
+# A reference list of all people associated with the project.
+# All other sections should refer to people by their canonical key
+# in the people section.
+
+	# ADD YOURSELF HERE IN ALPHABETICAL ORDER
+
+	[people.abronan]
+	Name = "Alexandre Beslic"
+	Email = "abronan@docker.com"
+	GitHub = "abronan"
+
+	[people.aluzzardi]
+	Name = "Andrea Luzzardi"
+	Email = "al@docker.com"
+	GitHub = "aluzzardi"
+
+	[people.sanimej]
+	Name = "Santhosh Manohar"
+	Email = "santhosh@docker.com"
+	GitHub = "sanimej"
+
+	[people.vieux]
+	Name = "Victor Vieux"
+	Email = "vieux@docker.com"
+	GitHub = "vieux"

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/README.md

@@ -3,6 +3,7 @@
 [![GoDoc](https://godoc.org/github.com/docker/libkv?status.png)](https://godoc.org/github.com/docker/libkv)
 [![Build Status](https://travis-ci.org/docker/libkv.svg?branch=master)](https://travis-ci.org/docker/libkv)
 [![Coverage Status](https://coveralls.io/repos/docker/libkv/badge.svg)](https://coveralls.io/r/docker/libkv)
+[![Go Report Card](https://goreportcard.com/badge/github.com/docker/libkv)](https://goreportcard.com/report/github.com/docker/libkv)
 
 `libkv` provides a `Go` native library to store metadata.
 
@@ -10,7 +11,7 @@ The goal of `libkv` is to abstract common store operations for multiple distribu
 
 For example, you can use it to store your metadata or for service discovery to register machines and endpoints inside your cluster.
 
-You can also easily implement a generic *Leader Election* on top of it (see the [swarm/leadership](https://github.com/docker/swarm/tree/master/leadership) package).
+You can also easily implement a generic *Leader Election* on top of it (see the [docker/leadership](https://github.com/docker/leadership) repository).
 
 As of now, `libkv` offers support for `Consul`, `Etcd`, `Zookeeper` (**Distributed** store) and `BoltDB` (**Local** store).
 
@@ -30,7 +31,7 @@ You can find examples of usage for `libkv` under in `docs/examples.go`. Optional
 
 `libkv` supports:
 - Consul versions >= `0.5.1` because it uses Sessions with `Delete` behavior for the use of `TTLs` (mimics zookeeper's Ephemeral node support), If you don't plan to use `TTLs`: you can use Consul version `0.4.0+`.
-- Etcd versions >= `2.0` because it uses the new `coreos/etcd/client`, this might change in the future as the support for `APIv3` comes along and adds mor capabilities.
+- Etcd versions >= `2.0` because it uses the new `coreos/etcd/client`, this might change in the future as the support for `APIv3` comes along and adds more capabilities.
 - Zookeeper versions >= `3.4.5`. Although this might work with previous version but this remains untested as of now.
 - Boltdb, which shouldn't be subject to any version dependencies.
 
@@ -83,7 +84,7 @@ Please refer to the `docs/compatibility.md` to see what are the special cases fo
 
 Other than those special cases, you should expect the same experience for basic operations like `Get`/`Put`, etc.
 
-Calls like `WatchTree` may return different events (or number of events) depending on the backend (for now, `Etcd` and `Consul` will likely return more events than `Zookeeper` that you should triage properly). Although you should be able to use it successfully to watch on events in an interchangeable way (see the **swarm/leadership** or **swarm/discovery** packages in **docker/swarm**).
+Calls like `WatchTree` may return different events (or number of events) depending on the backend (for now, `Etcd` and `Consul` will likely return more events than `Zookeeper` that you should triage properly). Although you should be able to use it successfully to watch on events in an interchangeable way (see the **docker/leadership** repository or the **pkg/discovery/kv** package in **docker/docker**).
 
 ## TLS
 
@@ -103,4 +104,4 @@ Want to hack on libkv? [Docker's contributions guidelines](https://github.com/do
 
 ##Copyright and license
 
-Copyright © 2014-2015 Docker, Inc. All rights reserved, except as follows. Code is released under the Apache 2.0 license. The README.md file, and files in the "docs" folder are licensed under the Creative Commons Attribution 4.0 International License under the terms and conditions set forth in the file "LICENSE.docs". You may obtain a duplicate copy of the same license, titled CC-BY-SA-4.0, at http://creativecommons.org/licenses/by/4.0/.
+Copyright © 2014-2016 Docker, Inc. All rights reserved, except as follows. Code is released under the Apache 2.0 license. The README.md file, and files in the "docs" folder are licensed under the Creative Commons Attribution 4.0 International License under the terms and conditions set forth in the file "LICENSE.docs". You may obtain a duplicate copy of the same license, titled CC-BY-SA-4.0, at http://creativecommons.org/licenses/by/4.0/.

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/libkv.go

@@ -25,7 +25,7 @@ var (
 	}()
 )
 
-// NewStore creates a an instance of store
+// NewStore creates an instance of store
 func NewStore(backend store.Backend, addrs []string, options *store.Config) (store.Store, error) {
 	if init, exists := initializers[backend]; exists {
 		return init(addrs, options)

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/store/boltdb/boltdb.go

@@ -19,8 +19,6 @@ var (
 	// ErrMultipleEndpointsUnsupported is thrown when multiple endpoints specified for
 	// BoltDB. Endpoint has to be a local file path
 	ErrMultipleEndpointsUnsupported = errors.New("boltdb supports one endpoint and should be a file path")
-	// ErrBoltBucketNotFound is thrown when specified BoltBD bucket doesn't exist in the DB
-	ErrBoltBucketNotFound = errors.New("boltdb bucket doesn't exist")
 	// ErrBoltBucketOptionMissing is thrown when boltBcuket config option is missing
 	ErrBoltBucketOptionMissing = errors.New("boltBucket config option missing")
 )
@@ -141,7 +139,7 @@ func (b *BoltDB) Get(key string) (*store.KVPair, error) {
 	err = db.View(func(tx *bolt.Tx) error {
 		bucket := tx.Bucket(b.boltBucket)
 		if bucket == nil {
-			return ErrBoltBucketNotFound
+			return store.ErrKeyNotFound
 		}
 
 		v := bucket.Get([]byte(key))
@@ -217,7 +215,7 @@ func (b *BoltDB) Delete(key string) error {
 	err = db.Update(func(tx *bolt.Tx) error {
 		bucket := tx.Bucket(b.boltBucket)
 		if bucket == nil {
-			return ErrBoltBucketNotFound
+			return store.ErrKeyNotFound
 		}
 		err := bucket.Delete([]byte(key))
 		return err
@@ -243,7 +241,7 @@ func (b *BoltDB) Exists(key string) (bool, error) {
 	err = db.View(func(tx *bolt.Tx) error {
 		bucket := tx.Bucket(b.boltBucket)
 		if bucket == nil {
-			return ErrBoltBucketNotFound
+			return store.ErrKeyNotFound
 		}
 
 		val = bucket.Get([]byte(key))
@@ -276,7 +274,7 @@ func (b *BoltDB) List(keyPrefix string) ([]*store.KVPair, error) {
 	err = db.View(func(tx *bolt.Tx) error {
 		bucket := tx.Bucket(b.boltBucket)
 		if bucket == nil {
-			return ErrBoltBucketNotFound
+			return store.ErrKeyNotFound
 		}
 
 		cursor := bucket.Cursor()
@@ -326,7 +324,7 @@ func (b *BoltDB) AtomicDelete(key string, previous *store.KVPair) (bool, error)
 	err = db.Update(func(tx *bolt.Tx) error {
 		bucket := tx.Bucket(b.boltBucket)
 		if bucket == nil {
-			return ErrBoltBucketNotFound
+			return store.ErrKeyNotFound
 		}
 
 		val = bucket.Get([]byte(key))
@@ -370,7 +368,7 @@ func (b *BoltDB) AtomicPut(key string, value []byte, previous *store.KVPair, opt
 		bucket := tx.Bucket(b.boltBucket)
 		if bucket == nil {
 			if previous != nil {
-				return ErrBoltBucketNotFound
+				return store.ErrKeyNotFound
 			}
 			bucket, err = tx.CreateBucket(b.boltBucket)
 			if err != nil {
@@ -381,7 +379,7 @@ func (b *BoltDB) AtomicPut(key string, value []byte, previous *store.KVPair, opt
 		// doesn't exist in the DB.
 		val = bucket.Get([]byte(key))
 		if previous == nil && len(val) != 0 {
-			return store.ErrKeyModified
+			return store.ErrKeyExists
 		}
 		if previous != nil {
 			if len(val) == 0 {
@@ -440,7 +438,7 @@ func (b *BoltDB) DeleteTree(keyPrefix string) error {
 	err = db.Update(func(tx *bolt.Tx) error {
 		bucket := tx.Bucket(b.boltBucket)
 		if bucket == nil {
-			return ErrBoltBucketNotFound
+			return store.ErrKeyNotFound
 		}
 
 		cursor := bucket.Cursor()

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/store/consul/consul.go

@@ -22,6 +22,14 @@ const (
 	// RenewSessionRetryMax is the number of time we should try
 	// to renew the session before giving up and throwing an error
 	RenewSessionRetryMax = 5
+
+	// MaxSessionDestroyAttempts is the maximum times we will try
+	// to explicitely destroy the session attached to a lock after
+	// the connectivity to the store has been lost
+	MaxSessionDestroyAttempts = 5
+
+	// defaultLockTTL is the default ttl for the consul lock
+	defaultLockTTL = 20 * time.Second
 )
 
 var (
@@ -186,6 +194,7 @@ func (s *Consul) Put(key string, value []byte, opts *store.WriteOptions) error {
 	p := &api.KVPair{
 		Key:   key,
 		Value: value,
+		Flags: api.LockFlagValue,
 	}
 
 	if opts != nil && opts.TTL > 0 {
@@ -378,44 +387,99 @@ func (s *Consul) NewLock(key string, options *store.LockOptions) (store.Locker,
 
 	lock := &consulLock{}
 
+	ttl := defaultLockTTL
+
 	if options != nil {
 		// Set optional TTL on Lock
 		if options.TTL != 0 {
-			entry := &api.SessionEntry{
-				Behavior:  api.SessionBehaviorRelease, // Release the lock when the session expires
-				TTL:       (options.TTL / 2).String(), // Consul multiplies the TTL by 2x
-				LockDelay: 1 * time.Millisecond,       // Virtually disable lock delay
-			}
-
-			// Create the key session
-			session, _, err := s.client.Session().Create(entry, nil)
-			if err != nil {
-				return nil, err
-			}
-
-			// Place the session on lock
-			lockOpts.Session = session
-
-			// Renew the session ttl lock periodically
-			go s.client.Session().RenewPeriodic(entry.TTL, session, nil, options.RenewLock)
-			lock.renewCh = options.RenewLock
+			ttl = options.TTL
 		}
-
 		// Set optional value on Lock
 		if options.Value != nil {
 			lockOpts.Value = options.Value
 		}
 	}
 
+	entry := &api.SessionEntry{
+		Behavior:  api.SessionBehaviorRelease, // Release the lock when the session expires
+		TTL:       (ttl / 2).String(),         // Consul multiplies the TTL by 2x
+		LockDelay: 1 * time.Millisecond,       // Virtually disable lock delay
+	}
+
+	// Create the key session
+	session, _, err := s.client.Session().Create(entry, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Place the session and renew chan on lock
+	lockOpts.Session = session
+	lock.renewCh = options.RenewLock
+
 	l, err := s.client.LockOpts(lockOpts)
 	if err != nil {
 		return nil, err
 	}
 
+	// Renew the session ttl lock periodically
+	s.renewLockSession(entry.TTL, session, options.RenewLock)
+
 	lock.lock = l
 	return lock, nil
 }
 
+// renewLockSession is used to renew a session Lock, it takes
+// a stopRenew chan which is used to explicitely stop the session
+// renew process. The renew routine never stops until a signal is
+// sent to this channel. If deleting the session fails because the
+// connection to the store is lost, it keeps trying to delete the
+// session periodically until it can contact the store, this ensures
+// that the lock is not maintained indefinitely which ensures liveness
+// over safety for the lock when the store becomes unavailable.
+func (s *Consul) renewLockSession(initialTTL string, id string, stopRenew chan struct{}) {
+	sessionDestroyAttempts := 0
+	ttl, err := time.ParseDuration(initialTTL)
+	if err != nil {
+		return
+	}
+	go func() {
+		for {
+			select {
+			case <-time.After(ttl / 2):
+				entry, _, err := s.client.Session().Renew(id, nil)
+				if err != nil {
+					// If an error occurs, continue until the
+					// session gets destroyed explicitely or
+					// the session ttl times out
+					continue
+				}
+				if entry == nil {
+					return
+				}
+
+				// Handle the server updating the TTL
+				ttl, _ = time.ParseDuration(entry.TTL)
+
+			case <-stopRenew:
+				// Attempt a session destroy
+				_, err := s.client.Session().Destroy(id, nil)
+				if err == nil {
+					return
+				}
+
+				if sessionDestroyAttempts >= MaxSessionDestroyAttempts {
+					return
+				}
+
+				// We can't destroy the session because the store
+				// is unavailable, wait for the session renew period
+				sessionDestroyAttempts++
+				time.Sleep(ttl / 2)
+			}
+		}
+	}()
+}
+
 // Lock attempts to acquire the lock and blocks while
 // doing so. It returns a channel that is closed if our
 // lock is lost or if an error occurs
@@ -436,7 +500,7 @@ func (l *consulLock) Unlock() error {
 // modified in the meantime, throws an error if this is the case
 func (s *Consul) AtomicPut(key string, value []byte, previous *store.KVPair, options *store.WriteOptions) (bool, *store.KVPair, error) {
 
-	p := &api.KVPair{Key: s.normalize(key), Value: value}
+	p := &api.KVPair{Key: s.normalize(key), Value: value, Flags: api.LockFlagValue}
 
 	if previous == nil {
 		// Consul interprets ModifyIndex = 0 as new key.
@@ -445,9 +509,14 @@ func (s *Consul) AtomicPut(key string, value []byte, previous *store.KVPair, opt
 		p.ModifyIndex = previous.LastIndex
 	}
 
-	if work, _, err := s.client.KV().CAS(p, nil); err != nil {
+	ok, _, err := s.client.KV().CAS(p, nil)
+	if err != nil {
 		return false, nil, err
-	} else if !work {
+	}
+	if !ok {
+		if previous == nil {
+			return false, nil, store.ErrKeyExists
+		}
 		return false, nil, store.ErrKeyModified
 	}
 
@@ -466,7 +535,7 @@ func (s *Consul) AtomicDelete(key string, previous *store.KVPair) (bool, error)
 		return false, store.ErrPreviousNotSpecified
 	}
 
-	p := &api.KVPair{Key: s.normalize(key), ModifyIndex: previous.LastIndex}
+	p := &api.KVPair{Key: s.normalize(key), ModifyIndex: previous.LastIndex, Flags: api.LockFlagValue}
 
 	// Extra Get operation to check on the key
 	_, err := s.Get(key)

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/store/etcd/etcd.go

@@ -75,6 +75,9 @@ func New(addrs []string, options *store.Config) (store.Store, error) {
 		if options.ConnectionTimeout != 0 {
 			setTimeout(cfg, options.ConnectionTimeout)
 		}
+		if options.Username != "" {
+			setCredentials(cfg, options.Username, options.Password)
+		}
 	}
 
 	c, err := etcd.New(*cfg)
@@ -119,6 +122,12 @@ func setTimeout(cfg *etcd.Config, time time.Duration) {
 	cfg.HeaderTimeoutPerRequest = time
 }
 
+// setCredentials sets the username/password credentials for connecting to Etcd
+func setCredentials(cfg *etcd.Config, username, password string) {
+	cfg.Username = username
+	cfg.Password = password
+}
+
 // Normalize the key for usage in Etcd
 func (s *Etcd) normalize(key string) string {
 	key = store.Normalize(key)
@@ -335,6 +344,10 @@ func (s *Etcd) AtomicPut(key string, value []byte, previous *store.KVPair, opts
 			if etcdError.Code == etcd.ErrorCodeTestFailed {
 				return false, nil, store.ErrKeyModified
 			}
+			// Node exists error (when PrevNoExist)
+			if etcdError.Code == etcd.ErrorCodeNodeExist {
+				return false, nil, store.ErrKeyExists
+			}
 		}
 		return false, nil, err
 	}
@@ -508,15 +521,15 @@ func (l *etcdLock) Lock(stopChan chan struct{}) (<-chan struct{}, error) {
 			// Wait for the key to be available or for
 			// a signal to stop trying to lock the key
 			select {
-			case _ = <-free:
+			case <-free:
 				break
 			case err := <-errorCh:
 				return nil, err
-			case _ = <-stopChan:
+			case <-stopChan:
 				return nil, ErrAbortTryLock
 			}
 
-			// Delete or Expire event occured
+			// Delete or Expire event occurred
 			// Retry
 		}
 	}

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/store/store.go

@@ -35,6 +35,8 @@ var (
 	ErrKeyNotFound = errors.New("Key not found in store")
 	// ErrPreviousNotSpecified is thrown when the previous value is not specified for an atomic operation
 	ErrPreviousNotSpecified = errors.New("Previous K/V pair should be provided for the Atomic operation")
+	// ErrKeyExists is thrown when the previous value exists in the case of an AtomicPut
+	ErrKeyExists = errors.New("Previous K/V pair exists, cannot complete Atomic operation")
 )
 
 // Config contains the options for a storage client
@@ -44,6 +46,8 @@ type Config struct {
 	ConnectionTimeout time.Duration
 	Bucket            string
 	PersistConnection bool
+	Username          string
+	Password          string
 }
 
 // ClientTLSConfig contains data for a Client TLS configuration in the form

libnetwork/Godeps/_workspace/src/github.com/docker/libkv/store/zookeeper/zookeeper.go

@@ -291,8 +291,8 @@ func (s *Zookeeper) DeleteTree(directory string) error {
 // AtomicPut put a value at "key" if the key has not been
 // modified in the meantime, throws an error if this is the case
 func (s *Zookeeper) AtomicPut(key string, value []byte, previous *store.KVPair, _ *store.WriteOptions) (bool, *store.KVPair, error) {
-
 	var lastIndex uint64
+
 	if previous != nil {
 		meta, err := s.client.Set(s.normalize(key), value, int32(previous.LastIndex))
 		if err != nil {
@@ -307,8 +307,9 @@ func (s *Zookeeper) AtomicPut(key string, value []byte, previous *store.KVPair,
 		// Interpret previous == nil as create operation.
 		_, err := s.client.Create(s.normalize(key), value, 0, zk.WorldACL(zk.PermAll))
 		if err != nil {
-			// Zookeeper will complain if the directory doesn't exist.
+			// Directory does not exist
 			if err == zk.ErrNoNode {
+
 				// Create the directory
 				parts := store.SplitKey(strings.TrimSuffix(key, "/"))
 				parts = parts[:len(parts)-1]
@@ -316,11 +317,22 @@ func (s *Zookeeper) AtomicPut(key string, value []byte, previous *store.KVPair,
 					// Failed to create the directory.
 					return false, nil, err
 				}
+
+				// Create the node
 				if _, err := s.client.Create(s.normalize(key), value, 0, zk.WorldACL(zk.PermAll)); err != nil {
+					// Node exist error (when previous nil)
+					if err == zk.ErrNodeExists {
+						return false, nil, store.ErrKeyExists
+					}
 					return false, nil, err
 				}
 
 			} else {
+				// Node Exists error (when previous nil)
+				if err == zk.ErrNodeExists {
+					return false, nil, store.ErrKeyExists
+				}
+
 				// Unhandled error
 				return false, nil, err
 			}