[integration-test] update go-connections in vendor

Author: Jimmy-Xu

vendor/src/github.com/docker/go-connections/sockets/tcp_socket.go

@@ -4,6 +4,8 @@ package sockets
 import (
 	"crypto/tls"
 	"net"
+	"net/http"
+	"time"
 )
 
 // NewTCPSocket creates a TCP socket listener with the specified address and
@@ -20,3 +22,23 @@ func NewTCPSocket(addr string, tlsConfig *tls.Config) (net.Listener, error) {
 	}
 	return l, nil
 }
+
+// ConfigureTCPTransport configures the specified Transport according to the
+// specified proto and addr.
+// If the proto is unix (using a unix socket to communicate) the compression
+// is disabled.
+func ConfigureTCPTransport(tr *http.Transport, proto, addr string) {
+	// Why 32? See https://github.com/docker/docker/pull/8035.
+	timeout := 32 * time.Second
+	if proto == "unix" {
+		// No need for compression in local communications.
+		tr.DisableCompression = true
+		tr.Dial = func(_, _ string) (net.Conn, error) {
+			return net.DialTimeout(proto, addr, timeout)
+		}
+	} else {
+		tr.Proxy = http.ProxyFromEnvironment
+		tr.Dial = (&net.Dialer{Timeout: timeout}).Dial
+	}
+}
+