@@ -520,8 +520,7 @@ func (s *DockerSuite) TestContainerApiCommit(c *check.C) {

 	var img resp

 	c.Assert(json.Unmarshal(b, &img), checker.IsNil)

-	cmd, err := inspectField(img.ID, "Config.Cmd")

-	c.Assert(err, checker.IsNil)

+	cmd := inspectField(c, img.ID, "Config.Cmd")

 	c.Assert(cmd, checker.Equals, "{[/bin/sh -c touch /test]}", check.Commentf("got wrong Cmd from commit: %q", cmd))

 	// sanity check, make sure the image is what we think it is

@@ -547,16 +546,13 @@ func (s *DockerSuite) TestContainerApiCommitWithLabelInConfig(c *check.C) {

 	var img resp

 	c.Assert(json.Unmarshal(b, &img), checker.IsNil)

-	label1, err := inspectFieldMap(img.ID, "Config.Labels", "key1")

-	c.Assert(err, checker.IsNil)

+	label1 := inspectFieldMap(c, img.ID, "Config.Labels", "key1")

 	c.Assert(label1, checker.Equals, "value1")

-	label2, err := inspectFieldMap(img.ID, "Config.Labels", "key2")

-	c.Assert(err, checker.IsNil)

+	label2 := inspectFieldMap(c, img.ID, "Config.Labels", "key2")

 	c.Assert(label2, checker.Equals, "value2")

-	cmd, err := inspectField(img.ID, "Config.Cmd")

-	c.Assert(err, checker.IsNil)

+	cmd := inspectField(c, img.ID, "Config.Cmd")

 	c.Assert(cmd, checker.Equals, "{[/bin/sh -c touch /test]}", check.Commentf("got wrong Cmd from commit: %q", cmd))

 	// sanity check, make sure the image is what we think it is

@@ -751,12 +747,10 @@ func (s *DockerSuite) TestContainerApiCreateWithCpuSharesCpuset(c *check.C) {

 	c.Assert(json.Unmarshal(body, &containerJSON), checker.IsNil)

-	out, err := inspectField(containerJSON.ID, "HostConfig.CpuShares")

-	c.Assert(err, checker.IsNil)

+	out := inspectField(c, containerJSON.ID, "HostConfig.CpuShares")

 	c.Assert(out, checker.Equals, "512")

-	outCpuset, errCpuset := inspectField(containerJSON.ID, "HostConfig.CpusetCpus")

-	c.Assert(errCpuset, checker.IsNil, check.Commentf("Output: %s", outCpuset))

+	outCpuset := inspectField(c, containerJSON.ID, "HostConfig.CpusetCpus")

 	c.Assert(outCpuset, checker.Equals, "0")

 }

@@ -853,16 +847,13 @@ func (s *DockerSuite) TestContainerApiPostCreateNull(c *check.C) {

 	}

 	var container createResp

 	c.Assert(json.Unmarshal(b, &container), checker.IsNil)

-	out, err := inspectField(container.ID, "HostConfig.CpusetCpus")

-	c.Assert(err, checker.IsNil)

+	out := inspectField(c, container.ID, "HostConfig.CpusetCpus")

 	c.Assert(out, checker.Equals, "")

-	outMemory, errMemory := inspectField(container.ID, "HostConfig.Memory")

+	outMemory := inspectField(c, container.ID, "HostConfig.Memory")

 	c.Assert(outMemory, checker.Equals, "0")

-	c.Assert(errMemory, checker.IsNil)

-	outMemorySwap, errMemorySwap := inspectField(container.ID, "HostConfig.MemorySwap")

+	outMemorySwap := inspectField(c, container.ID, "HostConfig.MemorySwap")

 	c.Assert(outMemorySwap, checker.Equals, "0")

-	c.Assert(errMemorySwap, checker.IsNil)

 }

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

@@ -917,7 +908,7 @@ func (s *DockerSuite) TestContainerApiRename(c *check.C) {

 	// 204 No Content is expected, not 200

 	c.Assert(statusCode, checker.Equals, http.StatusNoContent)

-	name, err := inspectField(containerID, "Name")

+	name := inspectField(c, containerID, "Name")

 	c.Assert(name, checker.Equals, "/"+newName, check.Commentf("Failed to rename container"))

 }

@@ -929,8 +920,7 @@ func (s *DockerSuite) TestContainerApiKill(c *check.C) {

 	c.Assert(err, checker.IsNil)

 	c.Assert(status, checker.Equals, http.StatusNoContent)

-	state, err := inspectField(name, "State.Running")

-	c.Assert(err, checker.IsNil)

+	state := inspectField(c, name, "State.Running")

 	c.Assert(state, checker.Equals, "false", check.Commentf("got wrong State from container %s: %q", name, state))

 }

@@ -1134,16 +1124,14 @@ func (s *DockerSuite) TestContainerApiDeleteRemoveLinks(c *check.C) {

 	id2 := strings.TrimSpace(out)

 	c.Assert(waitRun(id2), checker.IsNil)

-	links, err := inspectFieldJSON(id2, "HostConfig.Links")

-	c.Assert(err, checker.IsNil)

+	links := inspectFieldJSON(c, id2, "HostConfig.Links")

 	c.Assert(links, checker.Equals, "[\"/tlink1:/tlink2/tlink1\"]", check.Commentf("expected to have links between containers"))

 	status, b, err := sockRequest("DELETE", "/containers/tlink2/tlink1?link=1", nil)

 	c.Assert(err, check.IsNil)

 	c.Assert(status, check.Equals, http.StatusNoContent, check.Commentf(string(b)))

-	linksPostRm, err := inspectFieldJSON(id2, "HostConfig.Links")

-	c.Assert(err, checker.IsNil)

+	linksPostRm := inspectFieldJSON(c, id2, "HostConfig.Links")

 	c.Assert(linksPostRm, checker.Equals, "null", check.Commentf("call to api deleteContainer links should have removed the specified links"))

 }

@@ -1208,8 +1196,7 @@ func (s *DockerSuite) TestContainerApiChunkedEncoding(c *check.C) {

 	resp.Body.Close()

 	c.Assert(resp.StatusCode, checker.Equals, 204)

-	out, err = inspectFieldJSON(id, "HostConfig.Binds")

-	c.Assert(err, checker.IsNil)

+	out = inspectFieldJSON(c, id, "HostConfig.Binds")

 	var binds []string

 	c.Assert(json.NewDecoder(strings.NewReader(out)).Decode(&binds), checker.IsNil)

@@ -1308,8 +1295,7 @@ func (s *DockerSuite) TestPostContainersStartWithoutLinksInHostConfig(c *check.C

 	name := "test-host-config-links"

 	dockerCmd(c, append([]string{"create", "--name", name, "busybox"}, defaultSleepCommand...)...)

-	hc, err := inspectFieldJSON(name, "HostConfig")

-	c.Assert(err, checker.IsNil)

+	hc := inspectFieldJSON(c, name, "HostConfig")

 	config := `{"HostConfig":` + hc + `}`

 	res, b, err := sockRequestRaw("POST", "/containers/"+name+"/start", strings.NewReader(config), "application/json")

@@ -1327,8 +1313,7 @@ func (s *DockerSuite) TestPostContainersStartWithLinksInHostConfig(c *check.C) {

 	dockerCmd(c, "run", "--name", "foo", "-d", "busybox", "top")

 	dockerCmd(c, "create", "--name", name, "--link", "foo:bar", "busybox", "top")

-	hc, err := inspectFieldJSON(name, "HostConfig")

-	c.Assert(err, checker.IsNil)

+	hc := inspectFieldJSON(c, name, "HostConfig")

 	config := `{"HostConfig":` + hc + `}`

 	res, b, err := sockRequestRaw("POST", "/containers/"+name+"/start", strings.NewReader(config), "application/json")

@@ -1346,8 +1331,7 @@ func (s *DockerSuite) TestPostContainersStartWithLinksInHostConfigIdLinked(c *ch

 	id := strings.TrimSpace(out)

 	dockerCmd(c, "create", "--name", name, "--link", id, "busybox", "top")

-	hc, err := inspectFieldJSON(name, "HostConfig")

-	c.Assert(err, checker.IsNil)

+	hc := inspectFieldJSON(c, name, "HostConfig")

 	config := `{"HostConfig":` + hc + `}`

 	res, b, err := sockRequestRaw("POST", "/containers/"+name+"/start", strings.NewReader(config), "application/json")

@@ -1448,8 +1432,7 @@ func (s *DockerSuite) TestStartWithNilDNS(c *check.C) {

 	c.Assert(res.StatusCode, checker.Equals, http.StatusNoContent)

 	b.Close()

-	dns, err := inspectFieldJSON(containerID, "HostConfig.Dns")

-	c.Assert(err, checker.IsNil)

+	dns := inspectFieldJSON(c, containerID, "HostConfig.Dns")

 	c.Assert(dns, checker.Equals, "[]")

 }

@@ -67,7 +67,7 @@ func (s *DockerSuite) TestApiImagesSaveAndLoad(c *check.C) {

 	defer loadBody.Close()

 	c.Assert(res.StatusCode, checker.Equals, http.StatusOK)

-	inspectOut, _ := dockerCmd(c, "inspect", "--format='{{ .Id }}'", id)

+	inspectOut := inspectField(c, id, "Id")

 	c.Assert(strings.TrimSpace(string(inspectOut)), checker.Equals, id, check.Commentf("load did not work properly"))

 }

@@ -23,8 +23,7 @@ func (s *DockerSuite) TestApiUpdateContainer(c *check.C) {

 	_, _, err := sockRequest("POST", "/containers/"+name+"/update", hostConfig)

 	c.Assert(err, check.IsNil)

-	memory, err := inspectField(name, "HostConfig.Memory")

-	c.Assert(err, check.IsNil)

+	memory := inspectField(c, name, "HostConfig.Memory")

 	if memory != "314572800" {

 		c.Fatalf("Got the wrong memory value, we got %d, expected 314572800(300M).", memory)

 	}

@@ -32,8 +31,7 @@ func (s *DockerSuite) TestApiUpdateContainer(c *check.C) {

 	out, _ := dockerCmd(c, "exec", name, "cat", file)

 	c.Assert(strings.TrimSpace(out), checker.Equals, "314572800")

-	memorySwap, err := inspectField(name, "HostConfig.MemorySwap")

-	c.Assert(err, check.IsNil)

+	memorySwap := inspectField(c, name, "HostConfig.MemorySwap")

 	if memorySwap != "524288000" {

 		c.Fatalf("Got the wrong memorySwap value, we got %d, expected 524288000(500M).", memorySwap)

 	}

@@ -147,8 +147,7 @@ func (s *DockerSuite) TestAttachDisconnect(c *check.C) {

 	c.Assert(stdin.Close(), check.IsNil)

 	// Expect container to still be running after stdin is closed

-	running, err := inspectField(id, "State.Running")

-	c.Assert(err, check.IsNil)

+	running := inspectField(c, id, "State.Running")

 	c.Assert(running, check.Equals, "true")

 }

@@ -161,8 +161,7 @@ func (s *DockerSuite) TestAttachDetach(c *check.C) {

 		ch <- struct{}{}

 	}()

-	running, err := inspectField(id, "State.Running")

-	c.Assert(err, checker.IsNil)

+	running := inspectField(c, id, "State.Running")

 	c.Assert(running, checker.Equals, "true", check.Commentf("expected container to still be running"))

 	go func() {

@@ -214,8 +213,7 @@ func (s *DockerSuite) TestAttachDetachTruncatedID(c *check.C) {

 		ch <- struct{}{}

 	}()

-	running, err := inspectField(id, "State.Running")

-	c.Assert(err, checker.IsNil)

+	running := inspectField(c, id, "State.Running")

 	c.Assert(running, checker.Equals, "true", check.Commentf("expected container to still be running"))

 	go func() {

@@ -100,10 +100,7 @@ func (s *DockerSuite) TestBuildEnvironmentReplacementUser(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.User")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.User")

 	if res != `"foo"` {

 		c.Fatal("User foo from environment not in Config.User on image")

@@ -124,10 +121,7 @@ func (s *DockerSuite) TestBuildEnvironmentReplacementVolume(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Volumes")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.Volumes")

 	var volumes map[string]interface{}

@@ -156,10 +150,7 @@ func (s *DockerSuite) TestBuildEnvironmentReplacementExpose(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.ExposedPorts")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.ExposedPorts")

 	var exposedPorts map[string]interface{}

@@ -254,10 +245,7 @@ func (s *DockerSuite) TestBuildEnvironmentReplacementEnv(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Env")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.Env")

 	envResult := []string{}

@@ -315,10 +303,7 @@ func (s *DockerSuite) TestBuildHandleEscapes(c *check.C) {

 	var result map[string]map[string]struct{}

-	res, err := inspectFieldJSON(name, "Config.Volumes")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.Volumes")

 	if err = unmarshalJSON([]byte(res), &result); err != nil {

 		c.Fatal(err)

@@ -341,10 +326,7 @@ func (s *DockerSuite) TestBuildHandleEscapes(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err = inspectFieldJSON(name, "Config.Volumes")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res = inspectFieldJSON(c, name, "Config.Volumes")

 	if err = unmarshalJSON([]byte(res), &result); err != nil {

 		c.Fatal(err)

@@ -371,10 +353,7 @@ func (s *DockerSuite) TestBuildHandleEscapes(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err = inspectFieldJSON(name, "Config.Volumes")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res = inspectFieldJSON(c, name, "Config.Volumes")

 	if err = unmarshalJSON([]byte(res), &result); err != nil {

 		c.Fatal(err)

@@ -1971,10 +1950,7 @@ func (s *DockerSuite) TestBuildWithVolumes(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Volumes")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.Volumes")

 	err = unmarshalJSON([]byte(res), &result)

 	if err != nil {

@@ -2000,10 +1976,7 @@ func (s *DockerSuite) TestBuildMaintainer(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Author")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Author")

 	if res != expected {

 		c.Fatalf("Maintainer %s, expected %s", res, expected)

 	}

@@ -2022,10 +1995,7 @@ func (s *DockerSuite) TestBuildUser(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.User")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.User")

 	if res != expected {

 		c.Fatalf("User %s, expected %s", res, expected)

 	}

@@ -2048,10 +2018,7 @@ func (s *DockerSuite) TestBuildRelativeWorkdir(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.WorkingDir")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.WorkingDir")

 	if res != expected {

 		c.Fatalf("Workdir %s, expected %s", res, expected)

 	}

@@ -2071,10 +2038,7 @@ func (s *DockerSuite) TestBuildWorkdirWithEnvVariables(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.WorkingDir")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.WorkingDir")

 	if res != expected {

 		c.Fatalf("Workdir %s, expected %s", res, expected)

 	}

@@ -2134,10 +2098,7 @@ func (s *DockerSuite) TestBuildEnv(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Env")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Env")

 	if res != expected {

 		c.Fatalf("Env %s, expected %s", res, expected)

 	}

@@ -2152,8 +2113,7 @@ func (s *DockerSuite) TestBuildPATH(c *check.C) {

 		_, err := buildImage("testbldpath", dockerfile, true)

 		c.Assert(err, check.IsNil)

-		res, err := inspectField("testbldpath", "Config.Env")

-		c.Assert(err, check.IsNil)

+		res := inspectField(c, "testbldpath", "Config.Env")

 		if res != exp {

 			c.Fatalf("Env %q, expected %q for dockerfile:%q", res, exp, dockerfile)

@@ -2239,10 +2199,7 @@ func (s *DockerSuite) TestBuildCmd(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Cmd")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Cmd")

 	if res != expected {

 		c.Fatalf("Cmd %s, expected %s", res, expected)

 	}

@@ -2259,10 +2216,7 @@ func (s *DockerSuite) TestBuildExpose(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.ExposedPorts")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.ExposedPorts")

 	if res != expected {

 		c.Fatalf("Exposed ports %s, expected %s", res, expected)

 	}

@@ -2301,10 +2255,7 @@ func (s *DockerSuite) TestBuildExposeMorePorts(c *check.C) {

 	}

 	// check if all the ports are saved inside Config.ExposedPorts

-	res, err := inspectFieldJSON(name, "Config.ExposedPorts")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.ExposedPorts")

 	var exposedPorts map[string]interface{}

 	if err := json.Unmarshal([]byte(res), &exposedPorts); err != nil {

 		c.Fatal(err)

@@ -2331,10 +2282,7 @@ func (s *DockerSuite) TestBuildExposeOrder(c *check.C) {

 		if err != nil {

 			c.Fatal(err)

 		}

-		id, err := inspectField(name, "Id")

-		if err != nil {

-			c.Fatal(err)

-		}

+		id := inspectField(c, name, "Id")

 		return id

 	}

@@ -2356,10 +2304,7 @@ func (s *DockerSuite) TestBuildExposeUpperCaseProto(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.ExposedPorts")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.ExposedPorts")

 	if res != expected {

 		c.Fatalf("Exposed ports %s, expected %s", res, expected)

 	}

@@ -2377,10 +2322,7 @@ func (s *DockerSuite) TestBuildEmptyEntrypointInheritance(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Entrypoint")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Entrypoint")

 	expected := "{[/bin/echo]}"

 	if res != expected {

@@ -2394,10 +2336,7 @@ func (s *DockerSuite) TestBuildEmptyEntrypointInheritance(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err = inspectField(name2, "Config.Entrypoint")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res = inspectField(c, name2, "Config.Entrypoint")

 	expected = "{[]}"

@@ -2419,10 +2358,7 @@ func (s *DockerSuite) TestBuildEmptyEntrypoint(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Entrypoint")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Entrypoint")

 	if res != expected {

 		c.Fatalf("Entrypoint %s, expected %s", res, expected)

 	}

@@ -2440,10 +2376,7 @@ func (s *DockerSuite) TestBuildEntrypoint(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Entrypoint")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Entrypoint")

 	if res != expected {

 		c.Fatalf("Entrypoint %s, expected %s", res, expected)

 	}

@@ -3123,10 +3056,7 @@ func (s *DockerSuite) TestBuildEntrypointRunCleanup(c *check.C) {

 	if _, err := buildImageFromContext(name, ctx, true); err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Cmd")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Cmd")

 	// Cmd must be cleaned up

 	if res != "<nil>" {

 		c.Fatalf("Cmd %s, expected nil", res)

@@ -3185,10 +3115,7 @@ func (s *DockerSuite) TestBuildInheritance(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	ports1, err := inspectField(name, "Config.ExposedPorts")

-	if err != nil {

-		c.Fatal(err)

-	}

+	ports1 := inspectField(c, name, "Config.ExposedPorts")

 	_, err = buildImage(name,

 		fmt.Sprintf(`FROM %s

@@ -3198,17 +3125,11 @@ func (s *DockerSuite) TestBuildInheritance(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Entrypoint")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Entrypoint")

 	if expected := "{[/bin/echo]}"; res != expected {

 		c.Fatalf("Entrypoint %s, expected %s", res, expected)

 	}

-	ports2, err := inspectField(name, "Config.ExposedPorts")

-	if err != nil {

-		c.Fatal(err)

-	}

+	ports2 := inspectField(c, name, "Config.ExposedPorts")

 	if ports1 != ports2 {

 		c.Fatalf("Ports must be same: %s != %s", ports1, ports2)

 	}

@@ -3345,11 +3266,7 @@ docker.com>"

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Author")

-

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Author")

 	if res != "\"Docker IO <io@docker.com>\"" {

 		c.Fatalf("Parsed string did not match the escaped string. Got: %q", res)

@@ -4318,10 +4235,7 @@ func (s *DockerSuite) TestBuildFromGIT(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Author")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Author")

 	if res != "docker" {

 		c.Fatalf("Maintainer should be docker, got %s", res)

 	}

@@ -4347,10 +4261,7 @@ func (s *DockerSuite) TestBuildFromGITWithContext(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Author")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Author")

 	if res != "docker" {

 		c.Fatalf("Maintainer should be docker, got %s", res)

 	}

@@ -4411,8 +4322,7 @@ func (s *DockerSuite) TestBuildFromRemoteTarball(c *check.C) {

 	_, err = buildImageFromPath(name, server.URL()+"/testT.tar", true)

 	c.Assert(err, check.IsNil)

-	res, err := inspectField(name, "Author")

-	c.Assert(err, check.IsNil)

+	res := inspectField(c, name, "Author")

 	if res != "docker" {

 		c.Fatalf("Maintainer should be docker, got %s", res)

@@ -4435,18 +4345,12 @@ func (s *DockerSuite) TestBuildCleanupCmdOnEntrypoint(c *check.C) {

 		true); err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectField(name, "Config.Cmd")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectField(c, name, "Config.Cmd")

 	if res != "<nil>" {

 		c.Fatalf("Cmd %s, expected nil", res)

 	}

-	res, err = inspectField(name, "Config.Entrypoint")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res = inspectField(c, name, "Config.Entrypoint")

 	if expected := "{[cat]}"; res != expected {

 		c.Fatalf("Entrypoint %s, expected %s", res, expected)

 	}

@@ -4463,10 +4367,7 @@ func (s *DockerSuite) TestBuildClearCmd(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Cmd")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.Cmd")

 	if res != "[]" {

 		c.Fatalf("Cmd %s, expected %s", res, "[]")

 	}

@@ -4478,10 +4379,7 @@ func (s *DockerSuite) TestBuildEmptyCmd(c *check.C) {

 	if _, err := buildImage(name, "FROM scratch\nMAINTAINER quux\n", true); err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Cmd")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.Cmd")

 	if res != "null" {

 		c.Fatalf("Cmd %s, expected %s", res, "null")

 	}

@@ -4522,10 +4420,7 @@ func (s *DockerSuite) TestBuildCmdShDashC(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Cmd")

-	if err != nil {

-		c.Fatal(err, res)

-	}

+	res := inspectFieldJSON(c, name, "Config.Cmd")

 	expected := `["/bin/sh","-c","echo cmd"]`

@@ -4579,10 +4474,7 @@ func (s *DockerSuite) TestBuildCmdJSONNoShDashC(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Cmd")

-	if err != nil {

-		c.Fatal(err, res)

-	}

+	res := inspectFieldJSON(c, name, "Config.Cmd")

 	expected := `["echo","cmd"]`

@@ -4646,10 +4538,7 @@ func (s *DockerSuite) TestBuildEntrypointInheritanceInspect(c *check.C) {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name2, "Config.Entrypoint")

-	if err != nil {

-		c.Fatal(err, res)

-	}

+	res := inspectFieldJSON(c, name2, "Config.Entrypoint")

 	if res != expected {

 		c.Fatalf("Expected value %s not in Config.Entrypoint: %s", expected, res)

@@ -4756,10 +4645,7 @@ func (s *DockerSuite) TestBuildWithTabs(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "ContainerConfig.Cmd")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "ContainerConfig.Cmd")

 	expected1 := `["/bin/sh","-c","echo\tone\t\ttwo"]`

 	expected2 := `["/bin/sh","-c","echo\u0009one\u0009\u0009two"]` // syntactically equivalent, and what Go 1.3 generates

 	if res != expected1 && res != expected2 {

@@ -4779,10 +4665,7 @@ func (s *DockerSuite) TestBuildLabels(c *check.C) {

 	if err != nil {

 		c.Fatal(err)

 	}

-	res, err := inspectFieldJSON(name, "Config.Labels")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res := inspectFieldJSON(c, name, "Config.Labels")

 	if res != expected {

 		c.Fatalf("Labels %s, expected %s", res, expected)

 	}

@@ -5869,8 +5752,7 @@ func (s *DockerSuite) TestBuildStopSignal(c *check.C) {

 		 STOPSIGNAL SIGKILL`,

 		true)

 	c.Assert(err, check.IsNil)

-	res, err := inspectFieldJSON(name, "Config.StopSignal")

-	c.Assert(err, check.IsNil)

+	res := inspectFieldJSON(c, name, "Config.StopSignal")

 	if res != `"SIGKILL"` {

 		c.Fatalf("Signal %s, expected SIGKILL", res)

@@ -6138,18 +6020,12 @@ func (s *DockerSuite) TestBuildBuildTimeArgExpansion(c *check.C) {

 	var resMap map[string]interface{}

 	var resArr []string

 	res := ""

-	res, err = inspectField(imgName, "Config.WorkingDir")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res = inspectField(c, imgName, "Config.WorkingDir")

 	if res != filepath.ToSlash(filepath.Clean(wdVal)) {

 		c.Fatalf("Config.WorkingDir value mismatch. Expected: %s, got: %s", filepath.ToSlash(filepath.Clean(wdVal)), res)

 	}

-	err = inspectFieldAndMarshall(imgName, "Config.Env", &resArr)

-	if err != nil {

-		c.Fatal(err)

-	}

+	inspectFieldAndMarshall(c, imgName, "Config.Env", &resArr)

 	found := false

 	for _, v := range resArr {

@@ -6163,26 +6039,17 @@ func (s *DockerSuite) TestBuildBuildTimeArgExpansion(c *check.C) {

 			envVar, envVal, resArr)

 	}

-	err = inspectFieldAndMarshall(imgName, "Config.ExposedPorts", &resMap)

-	if err != nil {

-		c.Fatal(err)

-	}

+	inspectFieldAndMarshall(c, imgName, "Config.ExposedPorts", &resMap)

 	if _, ok := resMap[fmt.Sprintf("%s/tcp", exposeVal)]; !ok {

 		c.Fatalf("Config.ExposedPorts value mismatch. Expected exposed port: %s/tcp, got: %v", exposeVal, resMap)

 	}

-	res, err = inspectField(imgName, "Config.User")

-	if err != nil {

-		c.Fatal(err)

-	}

+	res = inspectField(c, imgName, "Config.User")

 	if res != userVal {

 		c.Fatalf("Config.User value mismatch. Expected: %s, got: %s", userVal, res)

 	}

-	err = inspectFieldAndMarshall(imgName, "Config.Volumes", &resMap)

-	if err != nil {

-		c.Fatal(err)

-	}

+	inspectFieldAndMarshall(c, imgName, "Config.Volumes", &resMap)

 	if _, ok := resMap[volVal]; !ok {

 		c.Fatalf("Config.Volumes value mismatch. Expected volume: %s, got: %v", volVal, resMap)

 	}

@@ -47,8 +47,7 @@ func (s *DockerSuite) TestBuildResourceConstraintsAreUsed(c *check.C) {

 		Ulimits    []*units.Ulimit

 	}

-	cfg, err := inspectFieldJSON(cID, "HostConfig")

-	c.Assert(err, checker.IsNil)

+	cfg := inspectFieldJSON(c, cID, "HostConfig")

 	var c1 hostConfig

 	err = json.Unmarshal([]byte(cfg), &c1)

@@ -66,8 +65,7 @@ func (s *DockerSuite) TestBuildResourceConstraintsAreUsed(c *check.C) {

 	// Make sure constraints aren't saved to image

 	dockerCmd(c, "run", "--name=test", name)

-	cfg, err = inspectFieldJSON("test", "HostConfig")

-	c.Assert(err, checker.IsNil)

+	cfg = inspectFieldJSON(c, "test", "HostConfig")

 	var c2 hostConfig

 	err = json.Unmarshal([]byte(cfg), &c2)

@@ -132,10 +132,9 @@ func (s *DockerRegistrySuite) TestCreateByDigest(c *check.C) {

 	imageReference := fmt.Sprintf("%s@%s", repoName, pushDigest)

 	containerName := "createByDigest"

-	out, _ := dockerCmd(c, "create", "--name", containerName, imageReference)

+	dockerCmd(c, "create", "--name", containerName, imageReference)

-	res, err := inspectField(containerName, "Config.Image")

-	c.Assert(err, checker.IsNil, check.Commentf("failed to get Config.Image: %s", out))

+	res := inspectField(c, containerName, "Config.Image")

 	c.Assert(res, checker.Equals, imageReference)

 }

@@ -153,8 +152,7 @@ func (s *DockerRegistrySuite) TestRunByDigest(c *check.C) {

 	c.Assert(matches, checker.HasLen, 2, check.Commentf("unable to parse digest from pull output: %s", out))

 	c.Assert(matches[1], checker.Equals, "1", check.Commentf("Expected %q, got %q", "1", matches[1]))

-	res, err := inspectField(containerName, "Config.Image")

-	c.Assert(err, checker.IsNil, check.Commentf("failed to get Config.Image: %s", out))

+	res := inspectField(c, containerName, "Config.Image")

 	c.Assert(res, checker.Equals, imageReference)

 }

@@ -168,15 +166,14 @@ func (s *DockerRegistrySuite) TestRemoveImageByDigest(c *check.C) {

 	dockerCmd(c, "pull", imageReference)

 	// make sure inspect runs ok

-	_, err = inspectField(imageReference, "Id")

-	c.Assert(err, checker.IsNil, check.Commentf("failed to inspect image"))

+	inspectField(c, imageReference, "Id")

 	// do the delete

 	err = deleteImages(imageReference)

 	c.Assert(err, checker.IsNil, check.Commentf("unexpected error deleting image"))

 	// try to inspect again - it should error this time

-	_, err = inspectField(imageReference, "Id")

+	_, err = inspectFieldWithError(imageReference, "Id")

 	//unexpected nil err trying to inspect what should be a non-existent image

 	c.Assert(err, checker.NotNil)

 	c.Assert(err.Error(), checker.Contains, "No such image")

@@ -192,8 +189,7 @@ func (s *DockerRegistrySuite) TestBuildByDigest(c *check.C) {

 	dockerCmd(c, "pull", imageReference)

 	// get the image id

-	imageID, err := inspectField(imageReference, "Id")

-	c.Assert(err, checker.IsNil, check.Commentf("error getting image id"))

+	imageID := inspectField(c, imageReference, "Id")

 	// do the build

 	name := "buildbydigest"

@@ -204,8 +200,7 @@ func (s *DockerRegistrySuite) TestBuildByDigest(c *check.C) {

 	c.Assert(err, checker.IsNil)

 	// get the build's image id

-	res, err := inspectField(name, "Config.Image")

-	c.Assert(err, checker.IsNil)

+	res := inspectField(c, name, "Config.Image")

 	// make sure they match

 	c.Assert(res, checker.Equals, imageID)

 }

@@ -223,11 +218,9 @@ func (s *DockerRegistrySuite) TestTagByDigest(c *check.C) {

 	tag := "tagbydigest"

 	dockerCmd(c, "tag", imageReference, tag)

-	expectedID, err := inspectField(imageReference, "Id")

-	c.Assert(err, checker.IsNil, check.Commentf("error getting original image id"))

+	expectedID := inspectField(c, imageReference, "Id")

-	tagID, err := inspectField(tag, "Id")

-	c.Assert(err, checker.IsNil, check.Commentf("error getting tagged image id"))

+	tagID := inspectField(c, tag, "Id")

 	c.Assert(tagID, checker.Equals, expectedID)

 }

@@ -389,8 +382,7 @@ func (s *DockerRegistrySuite) TestDeleteImageByIDOnlyPulledByDigest(c *check.C)

 	dockerCmd(c, "pull", imageReference)

 	// just in case...

-	imageID, err := inspectField(imageReference, "Id")

-	c.Assert(err, checker.IsNil, check.Commentf("error inspecting image id"))

+	imageID := inspectField(c, imageReference, "Id")

 	dockerCmd(c, "rmi", imageID)

 }

@@ -403,8 +395,7 @@ func (s *DockerRegistrySuite) TestDeleteImageWithDigestAndTag(c *check.C) {

 	imageReference := fmt.Sprintf("%s@%s", repoName, pushDigest)

 	dockerCmd(c, "pull", imageReference)

-	imageID, err := inspectField(imageReference, "Id")

-	c.Assert(err, checker.IsNil, check.Commentf("error inspecting image id"))

+	imageID := inspectField(c, imageReference, "Id")

 	repoTag := repoName + ":sometag"

 	repoTag2 := repoName + ":othertag"

@@ -414,13 +405,12 @@ func (s *DockerRegistrySuite) TestDeleteImageWithDigestAndTag(c *check.C) {

 	dockerCmd(c, "rmi", repoTag2)

 	// rmi should have deleted only repoTag2, because there's another tag

-	_, err = inspectField(repoTag, "Id")

-	c.Assert(err, checker.IsNil, check.Commentf("repoTag should not have been removed"))

+	inspectField(c, repoTag, "Id")

 	dockerCmd(c, "rmi", repoTag)

 	// rmi should have deleted the tag, the digest reference, and the image itself

-	_, err = inspectField(imageID, "Id")

+	_, err = inspectFieldWithError(imageID, "Id")

 	c.Assert(err, checker.NotNil, check.Commentf("image should have been deleted"))

 }

@@ -49,8 +49,7 @@ func (s *DockerSuite) TestCommitPausedContainer(c *check.C) {

 	out, _ = dockerCmd(c, "commit", cleanedContainerID)

-	out, err := inspectField(cleanedContainerID, "State.Paused")

-	c.Assert(err, checker.IsNil, check.Commentf("%s", out))

+	out = inspectField(c, cleanedContainerID, "State.Paused")

 	// commit should not unpause a paused container

 	c.Assert(out, checker.Contains, "true")

 }

@@ -139,8 +138,7 @@ func (s *DockerSuite) TestCommitChange(c *check.C) {

 	}