diff --git a/vendor/github.com/coreos/etcd/pkg/netutil/netutil.go b/vendor/github.com/coreos/etcd/pkg/netutil/netutil.go
new file mode 100644
index 0000000..e3db8c5
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/pkg/netutil/netutil.go
@@ -0,0 +1,187 @@
+// 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 netutil implements network-related utility functions.
+package netutil
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/url"
+	"reflect"
+	"sort"
+	"time"
+
+	"github.com/coreos/etcd/pkg/types"
+	"github.com/coreos/pkg/capnslog"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("github.com/coreos/etcd", "pkg/netutil")
+
+	// indirection for testing
+	resolveTCPAddr = resolveTCPAddrDefault
+)
+
+const retryInterval = time.Second
+
+// taken from go's ResolveTCP code but uses configurable ctx
+func resolveTCPAddrDefault(ctx context.Context, addr string) (*net.TCPAddr, error) {
+	host, port, serr := net.SplitHostPort(addr)
+	if serr != nil {
+		return nil, serr
+	}
+	portnum, perr := net.DefaultResolver.LookupPort(ctx, "tcp", port)
+	if perr != nil {
+		return nil, perr
+	}
+
+	var ips []net.IPAddr
+	if ip := net.ParseIP(host); ip != nil {
+		ips = []net.IPAddr{{IP: ip}}
+	} else {
+		// Try as a DNS name.
+		ipss, err := net.DefaultResolver.LookupIPAddr(ctx, host)
+		if err != nil {
+			return nil, err
+		}
+		ips = ipss
+	}
+	// randomize?
+	ip := ips[0]
+	return &net.TCPAddr{IP: ip.IP, Port: portnum, Zone: ip.Zone}, nil
+}
+
+// resolveTCPAddrs is a convenience wrapper for net.ResolveTCPAddr.
+// resolveTCPAddrs return a new set of url.URLs, in which all DNS hostnames
+// are resolved.
+func resolveTCPAddrs(ctx context.Context, urls [][]url.URL) ([][]url.URL, error) {
+	newurls := make([][]url.URL, 0)
+	for _, us := range urls {
+		nus := make([]url.URL, len(us))
+		for i, u := range us {
+			nu, err := url.Parse(u.String())
+			if err != nil {
+				return nil, fmt.Errorf("failed to parse %q (%v)", u.String(), err)
+			}
+			nus[i] = *nu
+		}
+		for i, u := range nus {
+			h, err := resolveURL(ctx, u)
+			if err != nil {
+				return nil, fmt.Errorf("failed to resolve %q (%v)", u.String(), err)
+			}
+			if h != "" {
+				nus[i].Host = h
+			}
+		}
+		newurls = append(newurls, nus)
+	}
+	return newurls, nil
+}
+
+func resolveURL(ctx context.Context, u url.URL) (string, error) {
+	if u.Scheme == "unix" || u.Scheme == "unixs" {
+		// unix sockets don't resolve over TCP
+		return "", nil
+	}
+	host, _, err := net.SplitHostPort(u.Host)
+	if err != nil {
+		plog.Errorf("could not parse url %s during tcp resolving", u.Host)
+		return "", err
+	}
+	if host == "localhost" || net.ParseIP(host) != nil {
+		return "", nil
+	}
+	for ctx.Err() == nil {
+		tcpAddr, err := resolveTCPAddr(ctx, u.Host)
+		if err == nil {
+			plog.Infof("resolving %s to %s", u.Host, tcpAddr.String())
+			return tcpAddr.String(), nil
+		}
+		plog.Warningf("failed resolving host %s (%v); retrying in %v", u.Host, err, retryInterval)
+		select {
+		case <-ctx.Done():
+			plog.Errorf("could not resolve host %s", u.Host)
+			return "", err
+		case <-time.After(retryInterval):
+		}
+	}
+	return "", ctx.Err()
+}
+
+// urlsEqual checks equality of url.URLS between two arrays.
+// This check pass even if an URL is in hostname and opposite is in IP address.
+func urlsEqual(ctx context.Context, a []url.URL, b []url.URL) (bool, error) {
+	if len(a) != len(b) {
+		return false, fmt.Errorf("len(%q) != len(%q)", urlsToStrings(a), urlsToStrings(b))
+	}
+	urls, err := resolveTCPAddrs(ctx, [][]url.URL{a, b})
+	if err != nil {
+		return false, err
+	}
+	preva, prevb := a, b
+	a, b = urls[0], urls[1]
+	sort.Sort(types.URLs(a))
+	sort.Sort(types.URLs(b))
+	for i := range a {
+		if !reflect.DeepEqual(a[i], b[i]) {
+			return false, fmt.Errorf("%q(resolved from %q) != %q(resolved from %q)",
+				a[i].String(), preva[i].String(),
+				b[i].String(), prevb[i].String(),
+			)
+		}
+	}
+	return true, nil
+}
+
+// URLStringsEqual returns "true" if given URLs are valid
+// and resolved to same IP addresses. Otherwise, return "false"
+// and error, if any.
+func URLStringsEqual(ctx context.Context, a []string, b []string) (bool, error) {
+	if len(a) != len(b) {
+		return false, fmt.Errorf("len(%q) != len(%q)", a, b)
+	}
+	urlsA := make([]url.URL, 0)
+	for _, str := range a {
+		u, err := url.Parse(str)
+		if err != nil {
+			return false, fmt.Errorf("failed to parse %q", str)
+		}
+		urlsA = append(urlsA, *u)
+	}
+	urlsB := make([]url.URL, 0)
+	for _, str := range b {
+		u, err := url.Parse(str)
+		if err != nil {
+			return false, fmt.Errorf("failed to parse %q", str)
+		}
+		urlsB = append(urlsB, *u)
+	}
+	return urlsEqual(ctx, urlsA, urlsB)
+}
+
+func urlsToStrings(us []url.URL) []string {
+	rs := make([]string, len(us))
+	for i := range us {
+		rs[i] = us[i].String()
+	}
+	return rs
+}
+
+func IsNetworkTimeoutError(err error) bool {
+	nerr, ok := err.(net.Error)
+	return ok && nerr.Timeout()
+}