merge branch 'pr-2781'

Sebastiaan van Stijn (7):
  errcheck: utils
  errcheck: signals
  errcheck: tty
  errcheck: libcontainer
  errcheck: libcontainer/nsenter
  errcheck: libcontainer/configs
  errcheck: libcontainer/integration

LGTM: AkihiroSuda cyphar
Closes #2781

libcontainer/configs/config.go

@@ -387,7 +387,7 @@ func (c Command) Run(s *specs.State) error {
 	case err := <-errC:
 		return err
 	case <-timerCh:
-		cmd.Process.Kill()
+		_ = cmd.Process.Kill()
 		<-errC
 		return fmt.Errorf("hook ran past specified timeout of %.1fs", c.Timeout.Seconds())
 	}

libcontainer/configs/config_test.go

@@ -145,12 +145,15 @@ func TestFuncHookRun(t *testing.T) {
 
 	fHook := configs.NewFunctionHook(func(s *specs.State) error {
 		if !reflect.DeepEqual(state, s) {
-			t.Errorf("Expected state %+v to equal %+v", state, s)
+			return fmt.Errorf("expected state %+v to equal %+v", state, s)
 		}
 		return nil
 	})
 
-	fHook.Run(state)
+	err := fHook.Run(state)
+	if err != nil {
+		t.Fatal(err)
+	}
 }
 
 func TestCommandHookRun(t *testing.T) {

libcontainer/container_linux.go

@@ -1352,7 +1352,7 @@ func (c *linuxContainer) Restore(process *Process, criuOpts *CriuOpts) error {
 	if err != nil {
 		return err
 	}
-	defer unix.Unmount(root, unix.MNT_DETACH)
+	defer unix.Unmount(root, unix.MNT_DETACH) //nolint: errcheck
 	t := criurpc.CriuReqType_RESTORE
 	req := &criurpc.CriuReq{
 		Type: &t,
@@ -1665,7 +1665,7 @@ func (c *linuxContainer) criuSwrk(process *Process, req *criurpc.CriuReq, opts *
 		break
 	}
 
-	criuClientCon.CloseWrite()
+	_ = criuClientCon.CloseWrite()
 	// cmd.Wait() waits cmd.goroutines which are used for proxying file descriptors.
 	// Here we want to wait only the CRIU process.
 	criuProcessState, err = criuProcess.Wait()

libcontainer/factory_linux.go

@@ -196,7 +196,11 @@ func New(root string, options ...func(*LinuxFactory) error) (Factory, error) {
 		Validator: validate.New(),
 		CriuPath:  "criu",
 	}
-	Cgroupfs(l)
+
+	if err := Cgroupfs(l); err != nil {
+		return nil, err
+	}
+
 	for _, opt := range options {
 		if opt == nil {
 			continue

libcontainer/factory_linux_test.go

@@ -122,15 +122,18 @@ func TestFactoryNewTmpfs(t *testing.T) {
 	if m.Source != "tmpfs" {
 		t.Fatalf("Source of root: %s, expected %s", m.Source, "tmpfs")
 	}
-	unix.Unmount(root, unix.MNT_DETACH)
+	err = unix.Unmount(root, unix.MNT_DETACH)
+	if err != nil {
+		t.Error("failed to unmount root:", err)
+	}
 }
 
 func TestFactoryLoadNotExists(t *testing.T) {
 	root, rerr := newTestRoot()
 	if rerr != nil {
 		t.Fatal(rerr)
 	}
-	defer os.RemoveAll(root)
+	defer os.RemoveAll(root) //nolint: errcheck
 	factory, err := New(root, Cgroupfs)
 	if err != nil {
 		t.Fatal(err)
@@ -153,7 +156,7 @@ func TestFactoryLoadContainer(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer os.RemoveAll(root)
+	defer os.RemoveAll(root) //nolint: errcheck
 	// setup default container config and state for mocking
 	var (
 		id            = "1"
@@ -219,7 +222,7 @@ func marshal(path string, v interface{}) error {
 	if err != nil {
 		return err
 	}
-	defer f.Close()
+	defer f.Close() //nolint: errcheck
 	return utils.WriteJSON(f, v)
 }
 

libcontainer/integration/checkpoint_test.go

@@ -14,29 +14,28 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func showFile(t *testing.T, fname string) error {
+func showFile(t *testing.T, fname string) {
 	t.Helper()
 	t.Logf("=== %s ===\n", fname)
 
 	f, err := os.Open(fname)
 	if err != nil {
 		t.Log(err)
-		return err
+		return
 	}
-	defer f.Close()
+	defer f.Close() //nolint: errcheck
 
 	scanner := bufio.NewScanner(f)
 	for scanner.Scan() {
 		t.Log(scanner.Text())
 	}
 
 	if err := scanner.Err(); err != nil {
-		return err
+		t.Log(err)
+		return
 	}
 
 	t.Logf("=== END ===\n")
-
-	return nil
 }
 
 func TestUsernsCheckpoint(t *testing.T) {
@@ -65,7 +64,7 @@ func testCheckpoint(t *testing.T, userns bool) {
 
 	root, err := newTestRoot()
 	ok(t, err)
-	defer os.RemoveAll(root)
+	defer remove(root)
 
 	rootfs, err := newRootfs()
 	ok(t, err)
@@ -80,7 +79,7 @@ func testCheckpoint(t *testing.T, userns bool) {
 
 	container, err := factory.Create("test", config)
 	ok(t, err)
-	defer container.Destroy()
+	defer destroyContainer(container)
 
 	stdinR, stdinW, err := os.Pipe()
 	ok(t, err)
@@ -97,8 +96,8 @@ func testCheckpoint(t *testing.T, userns bool) {
 	}
 
 	err = container.Run(&pconfig)
-	stdinR.Close()
-	defer stdinW.Close()
+	_ = stdinR.Close()
+	defer stdinW.Close() //nolint: errcheck
 	ok(t, err)
 
 	pid, err := pconfig.Pid()
@@ -109,7 +108,7 @@ func testCheckpoint(t *testing.T, userns bool) {
 
 	parentDir, err := ioutil.TempDir("", "criu-parent")
 	ok(t, err)
-	defer os.RemoveAll(parentDir)
+	defer remove(parentDir)
 
 	preDumpOpts := &libcontainer.CriuOpts{
 		ImagesDirectory: parentDir,
@@ -132,7 +131,7 @@ func testCheckpoint(t *testing.T, userns bool) {
 
 	imagesDir, err := ioutil.TempDir("", "criu")
 	ok(t, err)
-	defer os.RemoveAll(imagesDir)
+	defer remove(imagesDir)
 
 	checkpointOpts := &libcontainer.CriuOpts{
 		ImagesDirectory: imagesDir,
@@ -154,7 +153,7 @@ func testCheckpoint(t *testing.T, userns bool) {
 		t.Fatal("Unexpected state checkpoint: ", state)
 	}
 
-	stdinW.Close()
+	_ = stdinW.Close()
 	_, err = process.Wait()
 	ok(t, err)
 
@@ -174,8 +173,8 @@ func testCheckpoint(t *testing.T, userns bool) {
 	}
 
 	err = container.Restore(restoreProcessConfig, checkpointOpts)
-	restoreStdinR.Close()
-	defer restoreStdinW.Close()
+	_ = restoreStdinR.Close()
+	defer restoreStdinW.Close() //nolint: errcheck
 	if err != nil {
 		showFile(t, restoreLog)
 		t.Fatal(err)
@@ -196,7 +195,7 @@ func testCheckpoint(t *testing.T, userns bool) {
 	_, err = restoreStdinW.WriteString("Hello!")
 	ok(t, err)
 
-	restoreStdinW.Close()
+	_ = restoreStdinW.Close()
 	waitProcess(restoreProcessConfig, t)
 
 	output := restoreStdout.String()