@@ -2,13 +2,13 @@ package main

 import (

 	"bufio"

-	"bytes"

 	"io"

 	"net"

 	"net/http"

 	"strings"

 	"time"

+	"github.com/docker/docker/pkg/integration/checker"

 	"github.com/go-check/check"

 	"golang.org/x/net/websocket"

 )

@@ -18,23 +18,17 @@ func (s *DockerSuite) TestGetContainersAttachWebsocket(c *check.C) {

 	out, _ := dockerCmd(c, "run", "-dit", "busybox", "cat")

 	rwc, err := sockConn(time.Duration(10 * time.Second))

-	if err != nil {

-		c.Fatal(err)

-	}

+	c.Assert(err, checker.IsNil)

 	cleanedContainerID := strings.TrimSpace(out)

 	config, err := websocket.NewConfig(

 		"/containers/"+cleanedContainerID+"/attach/ws?stream=1&stdin=1&stdout=1&stderr=1",

 		"http://localhost",

 	)

-	if err != nil {

-		c.Fatal(err)

-	}

+	c.Assert(err, checker.IsNil)

 	ws, err := websocket.NewClient(config, rwc)

-	if err != nil {

-		c.Fatal(err)

-	}

+	c.Assert(err, checker.IsNil)

 	defer ws.Close()

 	expected := []byte("hello")

@@ -56,46 +50,36 @@ func (s *DockerSuite) TestGetContainersAttachWebsocket(c *check.C) {

 	select {

 	case err := <-inChan:

-		if err != nil {

-			c.Fatal(err)

-		}

+		c.Assert(err, checker.IsNil)

 	case <-time.After(5 * time.Second):

 		c.Fatal("Timeout writing to ws")

 	}

 	select {

 	case err := <-outChan:

-		if err != nil {

-			c.Fatal(err)

-		}

+		c.Assert(err, checker.IsNil)

 	case <-time.After(5 * time.Second):

 		c.Fatal("Timeout reading from ws")

 	}

-	if !bytes.Equal(expected, actual) {

-		c.Fatal("Expected output on websocket to match input")

-	}

+	c.Assert(actual, checker.DeepEquals, expected, check.Commentf("Websocket didn't return the expected data"))

 }

 // regression gh14320

 func (s *DockerSuite) TestPostContainersAttachContainerNotFound(c *check.C) {

 	status, body, err := sockRequest("POST", "/containers/doesnotexist/attach", nil)

-	c.Assert(status, check.Equals, http.StatusNotFound)

-	c.Assert(err, check.IsNil)

+	c.Assert(status, checker.Equals, http.StatusNotFound)

+	c.Assert(err, checker.IsNil)

 	expected := "no such id: doesnotexist\n"

-	if !strings.Contains(string(body), expected) {

-		c.Fatalf("Expected response body to contain %q", expected)

-	}

+	c.Assert(string(body), checker.Contains, expected)

 }

 func (s *DockerSuite) TestGetContainersWsAttachContainerNotFound(c *check.C) {

 	status, body, err := sockRequest("GET", "/containers/doesnotexist/attach/ws", nil)

-	c.Assert(status, check.Equals, http.StatusNotFound)

-	c.Assert(err, check.IsNil)

+	c.Assert(status, checker.Equals, http.StatusNotFound)

+	c.Assert(err, checker.IsNil)

 	expected := "no such id: doesnotexist\n"

-	if !strings.Contains(string(body), expected) {

-		c.Fatalf("Expected response body to contain %q", expected)

-	}

+	c.Assert(string(body), checker.Contains, expected)

 }

 func (s *DockerSuite) TestPostContainersAttach(c *check.C) {

@@ -105,7 +89,7 @@ func (s *DockerSuite) TestPostContainersAttach(c *check.C) {

 		defer conn.Close()

 		expected := []byte("success")

 		_, err := conn.Write(expected)

-		c.Assert(err, check.IsNil)

+		c.Assert(err, checker.IsNil)

 		conn.SetReadDeadline(time.Now().Add(time.Second))

 		lenHeader := 0

@@ -114,29 +98,29 @@ func (s *DockerSuite) TestPostContainersAttach(c *check.C) {

 		}

 		actual := make([]byte, len(expected)+lenHeader)

 		_, err = io.ReadFull(br, actual)

-		c.Assert(err, check.IsNil)

+		c.Assert(err, checker.IsNil)

 		if !tty {

 			fdMap := map[string]byte{

 				"stdin":  0,

 				"stdout": 1,

 				"stderr": 2,

 			}

-			c.Assert(actual[0], check.Equals, fdMap[stream])

+			c.Assert(actual[0], checker.Equals, fdMap[stream])

 		}

-		c.Assert(actual[lenHeader:], check.DeepEquals, expected, check.Commentf("Attach didn't return the expected data from %s", stream))

+		c.Assert(actual[lenHeader:], checker.DeepEquals, expected, check.Commentf("Attach didn't return the expected data from %s", stream))

 	}

 	expectTimeout := func(conn net.Conn, br *bufio.Reader, stream string) {

 		defer conn.Close()

 		_, err := conn.Write([]byte{'t'})

-		c.Assert(err, check.IsNil)

+		c.Assert(err, checker.IsNil)

 		conn.SetReadDeadline(time.Now().Add(time.Second))

 		actual := make([]byte, 1)

 		_, err = io.ReadFull(br, actual)

 		opErr, ok := err.(*net.OpError)

-		c.Assert(ok, check.Equals, true, check.Commentf("Error is expected to be *net.OpError, got %v", err))

-		c.Assert(opErr.Timeout(), check.Equals, true, check.Commentf("Read from %s is expected to timeout", stream))

+		c.Assert(ok, checker.Equals, true, check.Commentf("Error is expected to be *net.OpError, got %v", err))

+		c.Assert(opErr.Timeout(), checker.Equals, true, check.Commentf("Read from %s is expected to timeout", stream))

 	}

 	// Create a container that only emits stdout.

@@ -144,12 +128,12 @@ func (s *DockerSuite) TestPostContainersAttach(c *check.C) {

 	cid = strings.TrimSpace(cid)

 	// Attach to the container's stdout stream.

 	conn, br, err := sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain")

-	c.Assert(err, check.IsNil)

+	c.Assert(err, checker.IsNil)

 	// Check if the data from stdout can be received.

 	expectSuccess(conn, br, "stdout", false)

 	// Attach to the container's stderr stream.

 	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain")

-	c.Assert(err, check.IsNil)

+	c.Assert(err, checker.IsNil)

 	// Since the container only emits stdout, attaching to stderr should return nothing.

 	expectTimeout(conn, br, "stdout")

@@ -157,10 +141,10 @@ func (s *DockerSuite) TestPostContainersAttach(c *check.C) {

 	cid, _ = dockerCmd(c, "run", "-di", "busybox", "/bin/sh", "-c", "cat >&2")

 	cid = strings.TrimSpace(cid)

 	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain")

-	c.Assert(err, check.IsNil)

+	c.Assert(err, checker.IsNil)

 	expectSuccess(conn, br, "stderr", false)

 	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain")

-	c.Assert(err, check.IsNil)

+	c.Assert(err, checker.IsNil)

 	expectTimeout(conn, br, "stderr")

 	// Test with tty.

@@ -168,12 +152,12 @@ func (s *DockerSuite) TestPostContainersAttach(c *check.C) {

 	cid = strings.TrimSpace(cid)

 	// Attach to stdout only.

 	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain")

-	c.Assert(err, check.IsNil)

+	c.Assert(err, checker.IsNil)

 	expectSuccess(conn, br, "stdout", true)

 	// Attach without stdout stream.

 	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain")

-	c.Assert(err, check.IsNil)

+	c.Assert(err, checker.IsNil)

 	// Nothing should be received because both the stdout and stderr of the container will be

 	// sent to the client as stdout when tty is enabled.

 	expectTimeout(conn, br, "stdout")