diff --git a/Gopkg.lock b/Gopkg.lock
index 8c7af184a..358d7c263 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -706,7 +706,7 @@
   branch = "master"
   name = "github.com/gorilla/websocket"
   packages = ["."]
-  revision = "eb925808374e5ca90c83401a40d711dc08c0c0f6"
+  revision = "66b9c49e59c6c48f0ffce28c2d8b8a5678502c6d"
 
 [[projects]]
   name = "github.com/gravitational/trace"
@@ -1272,7 +1272,7 @@
     "roundrobin",
     "utils"
   ]
-  revision = "885e42fe04d8e0efa6c18facad4e0fc5757cde9b"
+  revision = "f6bbeac6d5c4c06f88ba07ed42983ff36a5b407e"
 
 [[projects]]
   name = "github.com/vulcand/predicate"
diff --git a/vendor/github.com/gorilla/websocket/client.go b/vendor/github.com/gorilla/websocket/client.go
index 8e90de27f..2e32fd506 100644
--- a/vendor/github.com/gorilla/websocket/client.go
+++ b/vendor/github.com/gorilla/websocket/client.go
@@ -6,12 +6,14 @@ package websocket
 
 import (
 	"bytes"
+	"context"
 	"crypto/tls"
 	"errors"
 	"io"
 	"io/ioutil"
 	"net"
 	"net/http"
+	"net/http/httptrace"
 	"net/url"
 	"strings"
 	"time"
@@ -51,6 +53,10 @@ type Dialer struct {
 	// NetDial is nil, net.Dial is used.
 	NetDial func(network, addr string) (net.Conn, error)
 
+	// NetDialContext specifies the dial function for creating TCP connections. If
+	// NetDialContext is nil, net.DialContext is used.
+	NetDialContext func(ctx context.Context, network, addr string) (net.Conn, error)
+
 	// Proxy specifies a function to return a proxy for a given
 	// Request. If the function returns a non-nil error, the
 	// request is aborted with the provided error.
@@ -69,6 +75,17 @@ type Dialer struct {
 	// do not limit the size of the messages that can be sent or received.
 	ReadBufferSize, WriteBufferSize int
 
+	// WriteBufferPool is a pool of buffers for write operations. If the value
+	// is not set, then write buffers are allocated to the connection for the
+	// lifetime of the connection.
+	//
+	// A pool is most useful when the application has a modest volume of writes
+	// across a large number of connections.
+	//
+	// Applications should use a single pool for each unique value of
+	// WriteBufferSize.
+	WriteBufferPool BufferPool
+
 	// Subprotocols specifies the client's requested subprotocols.
 	Subprotocols []string
 
@@ -84,6 +101,11 @@ type Dialer struct {
 	Jar http.CookieJar
 }
 
+// Dial creates a new client connection by calling DialContext with a background context.
+func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Response, error) {
+	return d.DialContext(context.Background(), urlStr, requestHeader)
+}
+
 var errMalformedURL = errors.New("malformed ws or wss URL")
 
 func hostPortNoPort(u *url.URL) (hostPort, hostNoPort string) {
@@ -111,19 +133,20 @@ var DefaultDialer = &Dialer{
 }
 
 // nilDialer is dialer to use when receiver is nil.
-var nilDialer Dialer = *DefaultDialer
+var nilDialer = *DefaultDialer
 
-// Dial creates a new client connection. Use requestHeader to specify the
+// DialContext creates a new client connection. Use requestHeader to specify the
 // origin (Origin), subprotocols (Sec-WebSocket-Protocol) and cookies (Cookie).
 // Use the response.Header to get the selected subprotocol
 // (Sec-WebSocket-Protocol) and cookies (Set-Cookie).
 //
+// The context will be used in the request and in the Dialer
+//
 // If the WebSocket handshake fails, ErrBadHandshake is returned along with a
 // non-nil *http.Response so that callers can handle redirects, authentication,
 // etcetera. The response body may not contain the entire response and does not
 // need to be closed by the application.
-func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Response, error) {
-
+func (d *Dialer) DialContext(ctx context.Context, urlStr string, requestHeader http.Header) (*Conn, *http.Response, error) {
 	if d == nil {
 		d = &nilDialer
 	}
@@ -161,6 +184,7 @@ func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Re
 		Header:     make(http.Header),
 		Host:       u.Host,
 	}
+	req = req.WithContext(ctx)
 
 	// Set the cookies present in the cookie jar of the dialer
 	if d.Jar != nil {
@@ -201,23 +225,33 @@ func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Re
 	}
 
 	if d.EnableCompression {
-		req.Header.Set("Sec-Websocket-Extensions", "permessage-deflate; server_no_context_takeover; client_no_context_takeover")
+		req.Header["Sec-WebSocket-Extensions"] = []string{"permessage-deflate; server_no_context_takeover; client_no_context_takeover"}
 	}
 
-	var deadline time.Time
 	if d.HandshakeTimeout != 0 {
-		deadline = time.Now().Add(d.HandshakeTimeout)
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, d.HandshakeTimeout)
+		defer cancel()
 	}
 
 	// Get network dial function.
-	netDial := d.NetDial
-	if netDial == nil {
-		netDialer := &net.Dialer{Deadline: deadline}
-		netDial = netDialer.Dial
+	var netDial func(network, add string) (net.Conn, error)
+
+	if d.NetDialContext != nil {
+		netDial = func(network, addr string) (net.Conn, error) {
+			return d.NetDialContext(ctx, network, addr)
+		}
+	} else if d.NetDial != nil {
+		netDial = d.NetDial
+	} else {
+		netDialer := &net.Dialer{}
+		netDial = func(network, addr string) (net.Conn, error) {
+			return netDialer.DialContext(ctx, network, addr)
+		}
 	}
 
 	// If needed, wrap the dial function to set the connection deadline.
-	if !deadline.Equal(time.Time{}) {
+	if deadline, ok := ctx.Deadline(); ok {
 		forwardDial := netDial
 		netDial = func(network, addr string) (net.Conn, error) {
 			c, err := forwardDial(network, addr)
@@ -249,7 +283,17 @@ func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Re
 	}
 
 	hostPort, hostNoPort := hostPortNoPort(u)
+	trace := httptrace.ContextClientTrace(ctx)
+	if trace != nil && trace.GetConn != nil {
+		trace.GetConn(hostPort)
+	}
+
 	netConn, err := netDial("tcp", hostPort)
+	if trace != nil && trace.GotConn != nil {
+		trace.GotConn(httptrace.GotConnInfo{
+			Conn: netConn,
+		})
+	}
 	if err != nil {
 		return nil, nil, err
 	}
@@ -267,22 +311,31 @@ func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Re
 		}
 		tlsConn := tls.Client(netConn, cfg)
 		netConn = tlsConn
-		if err := tlsConn.Handshake(); err != nil {
-			return nil, nil, err
+
+		var err error
+		if trace != nil {
+			err = doHandshakeWithTrace(trace, tlsConn, cfg)
+		} else {
+			err = doHandshake(tlsConn, cfg)
 		}
-		if !cfg.InsecureSkipVerify {
-			if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
-				return nil, nil, err
-			}
+
+		if err != nil {
+			return nil, nil, err
 		}
 	}
 
-	conn := newConn(netConn, false, d.ReadBufferSize, d.WriteBufferSize)
+	conn := newConn(netConn, false, d.ReadBufferSize, d.WriteBufferSize, d.WriteBufferPool, nil, nil)
 
 	if err := req.Write(netConn); err != nil {
 		return nil, nil, err
 	}
 
+	if trace != nil && trace.GotFirstResponseByte != nil {
+		if peek, err := conn.br.Peek(1); err == nil && len(peek) == 1 {
+			trace.GotFirstResponseByte()
+		}
+	}
+
 	resp, err := http.ReadResponse(conn.br, req)
 	if err != nil {
 		return nil, nil, err
@@ -328,3 +381,15 @@ func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Re
 	netConn = nil // to avoid close in defer.
 	return conn, resp, nil
 }
+
+func doHandshake(tlsConn *tls.Conn, cfg *tls.Config) error {
+	if err := tlsConn.Handshake(); err != nil {
+		return err
+	}
+	if !cfg.InsecureSkipVerify {
+		if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/vendor/github.com/gorilla/websocket/conn.go b/vendor/github.com/gorilla/websocket/conn.go
index 5f46bf4a5..d2a21c148 100644
--- a/vendor/github.com/gorilla/websocket/conn.go
+++ b/vendor/github.com/gorilla/websocket/conn.go
@@ -223,6 +223,20 @@ func isValidReceivedCloseCode(code int) bool {
 	return validReceivedCloseCodes[code] || (code >= 3000 && code <= 4999)
 }
 
+// BufferPool represents a pool of buffers. The *sync.Pool type satisfies this
+// interface.  The type of the value stored in a pool is not specified.
+type BufferPool interface {
+	// Get gets a value from the pool or returns nil if the pool is empty.
+	Get() interface{}
+	// Put adds a value to the pool.
+	Put(interface{})
+}
+
+// writePoolData is the type added to the write buffer pool. This wrapper is
+// used to prevent applications from peeking at and depending on the values
+// added to the pool.
+type writePoolData struct{ buf []byte }
+
 // The Conn type represents a WebSocket connection.
 type Conn struct {
 	conn        net.Conn
@@ -232,6 +246,8 @@ type Conn struct {
 	// Write fields
 	mu            chan bool // used as mutex to protect write to conn
 	writeBuf      []byte    // frame is constructed in this buffer.
+	writePool     BufferPool
+	writeBufSize  int
 	writeDeadline time.Time
 	writer        io.WriteCloser // the current writer returned to the application
 	isWriting     bool           // for best-effort concurrent write detection
@@ -263,64 +279,29 @@ type Conn struct {
 	newDecompressionReader func(io.Reader) io.ReadCloser
 }
 
-func newConn(conn net.Conn, isServer bool, readBufferSize, writeBufferSize int) *Conn {
-	return newConnBRW(conn, isServer, readBufferSize, writeBufferSize, nil)
-}
+func newConn(conn net.Conn, isServer bool, readBufferSize, writeBufferSize int, writeBufferPool BufferPool, br *bufio.Reader, writeBuf []byte) *Conn {
 
-type writeHook struct {
-	p []byte
-}
-
-func (wh *writeHook) Write(p []byte) (int, error) {
-	wh.p = p
-	return len(p), nil
-}
-
-func newConnBRW(conn net.Conn, isServer bool, readBufferSize, writeBufferSize int, brw *bufio.ReadWriter) *Conn {
-	mu := make(chan bool, 1)
-	mu <- true
-
-	var br *bufio.Reader
-	if readBufferSize == 0 && brw != nil && brw.Reader != nil {
-		// Reuse the supplied bufio.Reader if the buffer has a useful size.
-		// This code assumes that peek on a reader returns
-		// bufio.Reader.buf[:0].
-		brw.Reader.Reset(conn)
-		if p, err := brw.Reader.Peek(0); err == nil && cap(p) >= 256 {
-			br = brw.Reader
-		}
-	}
 	if br == nil {
 		if readBufferSize == 0 {
 			readBufferSize = defaultReadBufferSize
-		}
-		if readBufferSize < maxControlFramePayloadSize {
+		} else if readBufferSize < maxControlFramePayloadSize {
+			// must be large enough for control frame
 			readBufferSize = maxControlFramePayloadSize
 		}
 		br = bufio.NewReaderSize(conn, readBufferSize)
 	}
 
-	var writeBuf []byte
-	if writeBufferSize == 0 && brw != nil && brw.Writer != nil {
-		// Use the bufio.Writer's buffer if the buffer has a useful size. This
-		// code assumes that bufio.Writer.buf[:1] is passed to the
-		// bufio.Writer's underlying writer.
-		var wh writeHook
-		brw.Writer.Reset(&wh)
-		brw.Writer.WriteByte(0)
-		brw.Flush()
-		if cap(wh.p) >= maxFrameHeaderSize+256 {
-			writeBuf = wh.p[:cap(wh.p)]
-		}
-	}
-
-	if writeBuf == nil {
-		if writeBufferSize == 0 {
-			writeBufferSize = defaultWriteBufferSize
-		}
-		writeBuf = make([]byte, writeBufferSize+maxFrameHeaderSize)
+	if writeBufferSize <= 0 {
+		writeBufferSize = defaultWriteBufferSize
+	}
+	writeBufferSize += maxFrameHeaderSize
+
+	if writeBuf == nil && writeBufferPool == nil {
+		writeBuf = make([]byte, writeBufferSize)
 	}
 
+	mu := make(chan bool, 1)
+	mu <- true
 	c := &Conn{
 		isServer:               isServer,
 		br:                     br,
@@ -328,6 +309,8 @@ func newConnBRW(conn net.Conn, isServer bool, readBufferSize, writeBufferSize in
 		mu:                     mu,
 		readFinal:              true,
 		writeBuf:               writeBuf,
+		writePool:              writeBufferPool,
+		writeBufSize:           writeBufferSize,
 		enableWriteCompression: true,
 		compressionLevel:       defaultCompressionLevel,
 	}
@@ -370,6 +353,15 @@ func (c *Conn) writeFatal(err error) error {
 	return err
 }
 
+func (c *Conn) read(n int) ([]byte, error) {
+	p, err := c.br.Peek(n)
+	if err == io.EOF {
+		err = errUnexpectedEOF
+	}
+	c.br.Discard(len(p))
+	return p, err
+}
+
 func (c *Conn) write(frameType int, deadline time.Time, buf0, buf1 []byte) error {
 	<-c.mu
 	defer func() { c.mu <- true }()
@@ -475,7 +467,19 @@ func (c *Conn) prepWrite(messageType int) error {
 	c.writeErrMu.Lock()
 	err := c.writeErr
 	c.writeErrMu.Unlock()
-	return err
+	if err != nil {
+		return err
+	}
+
+	if c.writeBuf == nil {
+		wpd, ok := c.writePool.Get().(writePoolData)
+		if ok {
+			c.writeBuf = wpd.buf
+		} else {
+			c.writeBuf = make([]byte, c.writeBufSize)
+		}
+	}
+	return nil
 }
 
 // NextWriter returns a writer for the next message to send. The writer's Close
@@ -601,6 +605,10 @@ func (w *messageWriter) flushFrame(final bool, extra []byte) error {
 
 	if final {
 		c.writer = nil
+		if c.writePool != nil {
+			c.writePool.Put(writePoolData{buf: c.writeBuf})
+			c.writeBuf = nil
+		}
 		return nil
 	}
 
diff --git a/vendor/github.com/gorilla/websocket/conn_read.go b/vendor/github.com/gorilla/websocket/conn_read.go
deleted file mode 100644
index 1ea15059e..000000000
--- a/vendor/github.com/gorilla/websocket/conn_read.go
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build go1.5
-
-package websocket
-
-import "io"
-
-func (c *Conn) read(n int) ([]byte, error) {
-	p, err := c.br.Peek(n)
-	if err == io.EOF {
-		err = errUnexpectedEOF
-	}
-	c.br.Discard(len(p))
-	return p, err
-}
diff --git a/vendor/github.com/gorilla/websocket/conn_read_legacy.go b/vendor/github.com/gorilla/websocket/conn_read_legacy.go
deleted file mode 100644
index 018541cf6..000000000
--- a/vendor/github.com/gorilla/websocket/conn_read_legacy.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build !go1.5
-
-package websocket
-
-import "io"
-
-func (c *Conn) read(n int) ([]byte, error) {
-	p, err := c.br.Peek(n)
-	if err == io.EOF {
-		err = errUnexpectedEOF
-	}
-	if len(p) > 0 {
-		// advance over the bytes just read
-		io.ReadFull(c.br, p)
-	}
-	return p, err
-}
diff --git a/vendor/github.com/gorilla/websocket/prepared.go b/vendor/github.com/gorilla/websocket/prepared.go
index 1efffbd1e..74ec565d2 100644
--- a/vendor/github.com/gorilla/websocket/prepared.go
+++ b/vendor/github.com/gorilla/websocket/prepared.go
@@ -19,7 +19,6 @@ import (
 type PreparedMessage struct {
 	messageType int
 	data        []byte
-	err         error
 	mu          sync.Mutex
 	frames      map[prepareKey]*preparedFrame
 }
diff --git a/vendor/github.com/gorilla/websocket/proxy.go b/vendor/github.com/gorilla/websocket/proxy.go
index 102538bd3..bf2478e43 100644
--- a/vendor/github.com/gorilla/websocket/proxy.go
+++ b/vendor/github.com/gorilla/websocket/proxy.go
@@ -14,7 +14,7 @@ import (
 	"strings"
 )
 
-type netDialerFunc func(netowrk, addr string) (net.Conn, error)
+type netDialerFunc func(network, addr string) (net.Conn, error)
 
 func (fn netDialerFunc) Dial(network, addr string) (net.Conn, error) {
 	return fn(network, addr)
diff --git a/vendor/github.com/gorilla/websocket/server.go b/vendor/github.com/gorilla/websocket/server.go
index 3e96a00c8..a761824b3 100644
--- a/vendor/github.com/gorilla/websocket/server.go
+++ b/vendor/github.com/gorilla/websocket/server.go
@@ -7,7 +7,7 @@ package websocket
 import (
 	"bufio"
 	"errors"
-	"net"
+	"io"
 	"net/http"
 	"net/url"
 	"strings"
@@ -33,10 +33,23 @@ type Upgrader struct {
 	// or received.
 	ReadBufferSize, WriteBufferSize int
 
+	// WriteBufferPool is a pool of buffers for write operations. If the value
+	// is not set, then write buffers are allocated to the connection for the
+	// lifetime of the connection.
+	//
+	// A pool is most useful when the application has a modest volume of writes
+	// across a large number of connections.
+	//
+	// Applications should use a single pool for each unique value of
+	// WriteBufferSize.
+	WriteBufferPool BufferPool
+
 	// Subprotocols specifies the server's supported protocols in order of
-	// preference. If this field is set, then the Upgrade method negotiates a
+	// preference. If this field is not nil, then the Upgrade method negotiates a
 	// subprotocol by selecting the first match in this list with a protocol
-	// requested by the client.
+	// requested by the client. If there's no match, then no protocol is
+	// negotiated (the Sec-Websocket-Protocol header is not included in the
+	// handshake response).
 	Subprotocols []string
 
 	// Error specifies the function for generating HTTP error responses. If Error
@@ -103,7 +116,7 @@ func (u *Upgrader) selectSubprotocol(r *http.Request, responseHeader http.Header
 //
 // The responseHeader is included in the response to the client's upgrade
 // request. Use the responseHeader to specify cookies (Set-Cookie) and the
-// application negotiated subprotocol (Sec-Websocket-Protocol).
+// application negotiated subprotocol (Sec-WebSocket-Protocol).
 //
 // If the upgrade fails, then Upgrade replies to the client with an HTTP error
 // response.
@@ -127,7 +140,7 @@ func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeade
 	}
 
 	if _, ok := responseHeader["Sec-Websocket-Extensions"]; ok {
-		return u.returnError(w, r, http.StatusInternalServerError, "websocket: application specific 'Sec-Websocket-Extensions' headers are unsupported")
+		return u.returnError(w, r, http.StatusInternalServerError, "websocket: application specific 'Sec-WebSocket-Extensions' headers are unsupported")
 	}
 
 	checkOrigin := u.CheckOrigin
@@ -140,7 +153,7 @@ func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeade
 
 	challengeKey := r.Header.Get("Sec-Websocket-Key")
 	if challengeKey == "" {
-		return u.returnError(w, r, http.StatusBadRequest, "websocket: not a websocket handshake: `Sec-Websocket-Key' header is missing or blank")
+		return u.returnError(w, r, http.StatusBadRequest, "websocket: not a websocket handshake: `Sec-WebSocket-Key' header is missing or blank")
 	}
 
 	subprotocol := u.selectSubprotocol(r, responseHeader)
@@ -157,17 +170,12 @@ func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeade
 		}
 	}
 
-	var (
-		netConn net.Conn
-		err     error
-	)
-
 	h, ok := w.(http.Hijacker)
 	if !ok {
 		return u.returnError(w, r, http.StatusInternalServerError, "websocket: response does not implement http.Hijacker")
 	}
 	var brw *bufio.ReadWriter
-	netConn, brw, err = h.Hijack()
+	netConn, brw, err := h.Hijack()
 	if err != nil {
 		return u.returnError(w, r, http.StatusInternalServerError, err.Error())
 	}
@@ -177,7 +185,21 @@ func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeade
 		return nil, errors.New("websocket: client sent data before handshake is complete")
 	}
 
-	c := newConnBRW(netConn, true, u.ReadBufferSize, u.WriteBufferSize, brw)
+	var br *bufio.Reader
+	if u.ReadBufferSize == 0 && bufioReaderSize(netConn, brw.Reader) > 256 {
+		// Reuse hijacked buffered reader as connection reader.
+		br = brw.Reader
+	}
+
+	buf := bufioWriterBuffer(netConn, brw.Writer)
+
+	var writeBuf []byte
+	if u.WriteBufferPool == nil && u.WriteBufferSize == 0 && len(buf) >= maxFrameHeaderSize+256 {
+		// Reuse hijacked write buffer as connection buffer.
+		writeBuf = buf
+	}
+
+	c := newConn(netConn, true, u.ReadBufferSize, u.WriteBufferSize, u.WriteBufferPool, br, writeBuf)
 	c.subprotocol = subprotocol
 
 	if compress {
@@ -185,17 +207,23 @@ func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeade
 		c.newDecompressionReader = decompressNoContextTakeover
 	}
 
-	p := c.writeBuf[:0]
+	// Use larger of hijacked buffer and connection write buffer for header.
+	p := buf
+	if len(c.writeBuf) > len(p) {
+		p = c.writeBuf
+	}
+	p = p[:0]
+
 	p = append(p, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: "...)
 	p = append(p, computeAcceptKey(challengeKey)...)
 	p = append(p, "\r\n"...)
 	if c.subprotocol != "" {
-		p = append(p, "Sec-Websocket-Protocol: "...)
+		p = append(p, "Sec-WebSocket-Protocol: "...)
 		p = append(p, c.subprotocol...)
 		p = append(p, "\r\n"...)
 	}
 	if compress {
-		p = append(p, "Sec-Websocket-Extensions: permessage-deflate; server_no_context_takeover; client_no_context_takeover\r\n"...)
+		p = append(p, "Sec-WebSocket-Extensions: permessage-deflate; server_no_context_takeover; client_no_context_takeover\r\n"...)
 	}
 	for k, vs := range responseHeader {
 		if k == "Sec-Websocket-Protocol" {
@@ -296,3 +324,40 @@ func IsWebSocketUpgrade(r *http.Request) bool {
 	return tokenListContainsValue(r.Header, "Connection", "upgrade") &&
 		tokenListContainsValue(r.Header, "Upgrade", "websocket")
 }
+
+// bufioReaderSize size returns the size of a bufio.Reader.
+func bufioReaderSize(originalReader io.Reader, br *bufio.Reader) int {
+	// This code assumes that peek on a reset reader returns
+	// bufio.Reader.buf[:0].
+	// TODO: Use bufio.Reader.Size() after Go 1.10
+	br.Reset(originalReader)
+	if p, err := br.Peek(0); err == nil {
+		return cap(p)
+	}
+	return 0
+}
+
+// writeHook is an io.Writer that records the last slice passed to it vio
+// io.Writer.Write.
+type writeHook struct {
+	p []byte
+}
+
+func (wh *writeHook) Write(p []byte) (int, error) {
+	wh.p = p
+	return len(p), nil
+}
+
+// bufioWriterBuffer grabs the buffer from a bufio.Writer.
+func bufioWriterBuffer(originalWriter io.Writer, bw *bufio.Writer) []byte {
+	// This code assumes that bufio.Writer.buf[:1] is passed to the
+	// bufio.Writer's underlying writer.
+	var wh writeHook
+	bw.Reset(&wh)
+	bw.WriteByte(0)
+	bw.Flush()
+
+	bw.Reset(originalWriter)
+
+	return wh.p[:cap(wh.p)]
+}
diff --git a/vendor/github.com/gorilla/websocket/trace.go b/vendor/github.com/gorilla/websocket/trace.go
new file mode 100644
index 000000000..834f122a0
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/trace.go
@@ -0,0 +1,19 @@
+// +build go1.8
+
+package websocket
+
+import (
+	"crypto/tls"
+	"net/http/httptrace"
+)
+
+func doHandshakeWithTrace(trace *httptrace.ClientTrace, tlsConn *tls.Conn, cfg *tls.Config) error {
+	if trace.TLSHandshakeStart != nil {
+		trace.TLSHandshakeStart()
+	}
+	err := doHandshake(tlsConn, cfg)
+	if trace.TLSHandshakeDone != nil {
+		trace.TLSHandshakeDone(tlsConn.ConnectionState(), err)
+	}
+	return err
+}
diff --git a/vendor/github.com/gorilla/websocket/trace_17.go b/vendor/github.com/gorilla/websocket/trace_17.go
new file mode 100644
index 000000000..77d05a0b5
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/trace_17.go
@@ -0,0 +1,12 @@
+// +build !go1.8
+
+package websocket
+
+import (
+	"crypto/tls"
+	"net/http/httptrace"
+)
+
+func doHandshakeWithTrace(trace *httptrace.ClientTrace, tlsConn *tls.Conn, cfg *tls.Config) error {
+	return doHandshake(tlsConn, cfg)
+}
diff --git a/vendor/github.com/gorilla/websocket/util.go b/vendor/github.com/gorilla/websocket/util.go
index 385fa01be..354001e1e 100644
--- a/vendor/github.com/gorilla/websocket/util.go
+++ b/vendor/github.com/gorilla/websocket/util.go
@@ -178,7 +178,7 @@ headers:
 	return false
 }
 
-// parseExtensiosn parses WebSocket extensions from a header.
+// parseExtensions parses WebSocket extensions from a header.
 func parseExtensions(header http.Header) []map[string]string {
 	// From RFC 6455:
 	//
diff --git a/vendor/github.com/vulcand/oxy/forward/fwd.go b/vendor/github.com/vulcand/oxy/forward/fwd.go
index 3a715e479..5a8e81c77 100644
--- a/vendor/github.com/vulcand/oxy/forward/fwd.go
+++ b/vendor/github.com/vulcand/oxy/forward/fwd.go
@@ -259,6 +259,8 @@ func New(setters ...optSetter) (*Forwarder, error) {
 		errorHandler: f.errHandler,
 	}
 
+	f.postConfig()
+
 	return f, nil
 }
 
@@ -342,7 +344,7 @@ func (f *httpForwarder) serveWebSocket(w http.ResponseWriter, req *http.Request,
 		// WebSocket is only in http/1.1
 		dialer.TLSClientConfig.NextProtos = []string{"http/1.1"}
 	}
-	targetConn, resp, err := dialer.Dial(outReq.URL.String(), outReq.Header)
+	targetConn, resp, err := dialer.DialContext(outReq.Context(), outReq.URL.String(), outReq.Header)
 	if err != nil {
 		if resp == nil {
 			ctx.errHandler.ServeHTTP(w, req, err)
diff --git a/vendor/github.com/vulcand/oxy/forward/post_config.go b/vendor/github.com/vulcand/oxy/forward/post_config.go
new file mode 100644
index 000000000..1c4b12316
--- /dev/null
+++ b/vendor/github.com/vulcand/oxy/forward/post_config.go
@@ -0,0 +1,5 @@
+// +build go1.11
+
+package forward
+
+func (f *Forwarder) postConfig() {}
diff --git a/vendor/github.com/vulcand/oxy/forward/post_config_18.go b/vendor/github.com/vulcand/oxy/forward/post_config_18.go
new file mode 100644
index 000000000..7fee6843c
--- /dev/null
+++ b/vendor/github.com/vulcand/oxy/forward/post_config_18.go
@@ -0,0 +1,42 @@
+// +build !go1.11
+
+package forward
+
+import (
+	"context"
+	"net/http"
+)
+
+type key string
+
+const (
+	teHeader key = "TeHeader"
+)
+
+type TeTrailerRoundTripper struct {
+	http.RoundTripper
+}
+
+func (t *TeTrailerRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	teHeader := req.Context().Value(teHeader)
+	if teHeader != nil {
+		req.Header.Set("Te", teHeader.(string))
+	}
+	return t.RoundTripper.RoundTrip(req)
+}
+
+type TeTrailerRewriter struct {
+	ReqRewriter
+}
+
+func (t *TeTrailerRewriter) Rewrite(req *http.Request) {
+	if req.Header.Get("Te") == "trailers" {
+		*req = *req.WithContext(context.WithValue(req.Context(), teHeader, req.Header.Get("Te")))
+	}
+	t.ReqRewriter.Rewrite(req)
+}
+
+func (f *Forwarder) postConfig() {
+	f.roundTripper = &TeTrailerRoundTripper{RoundTripper: f.roundTripper}
+	f.rewriter = &TeTrailerRewriter{ReqRewriter: f.rewriter}
+}
diff --git a/vendor/github.com/vulcand/oxy/forward/rewrite.go b/vendor/github.com/vulcand/oxy/forward/rewrite.go
index 60c1a1947..b5f8da154 100644
--- a/vendor/github.com/vulcand/oxy/forward/rewrite.go
+++ b/vendor/github.com/vulcand/oxy/forward/rewrite.go
@@ -69,12 +69,6 @@ func (rw *HeaderRewriter) Rewrite(req *http.Request) {
 	if rw.Hostname != "" {
 		req.Header.Set(XForwardedServer, rw.Hostname)
 	}
-
-	if !IsWebsocketRequest(req) {
-		// Remove hop-by-hop headers to the backend.  Especially important is "Connection" because we want a persistent
-		// connection, regardless of what the client sent to us.
-		utils.RemoveHeaders(req.Header, HopHeaders...)
-	}
 }
 
 func forwardedPort(req *http.Request) string {