refactor: fix part of megacheck issue

apis/filters/parse.go

@@ -152,10 +152,7 @@ func FromParam(p string) (Args, error) {
 
 	raw := []byte(p)
 	err := json.Unmarshal(raw, &args)
-	if err != nil {
-		return args, err
-	}
-	return args, nil
+	return args, err
 }
 
 // FromFilterOpts parse key=value to Args string from cli opts

apis/opts/config/blkio.go

@@ -66,9 +66,7 @@ func (w *WeightDevice) Type() string {
 // Value returns all values as type WeightDevice
 func (w *WeightDevice) Value() []*types.WeightDevice {
 	var weightDevice []*types.WeightDevice
-	for _, v := range w.values {
-		weightDevice = append(weightDevice, v)
-	}
+	weightDevice = append(weightDevice, w.values...)
 
 	return weightDevice
 }
@@ -124,9 +122,7 @@ func (t *ThrottleBpsDevice) Type() string {
 // Value returns all values as type ThrottleDevice
 func (t *ThrottleBpsDevice) Value() []*types.ThrottleDevice {
 	var throttleDevice []*types.ThrottleDevice
-	for _, v := range t.values {
-		throttleDevice = append(throttleDevice, v)
-	}
+	throttleDevice = append(throttleDevice, t.values...)
 
 	return throttleDevice
 }
@@ -182,9 +178,7 @@ func (t *ThrottleIOpsDevice) Type() string {
 // Value returns all values
 func (t *ThrottleIOpsDevice) Value() []*types.ThrottleDevice {
 	var throttleDevice []*types.ThrottleDevice
-	for _, v := range t.values {
-		throttleDevice = append(throttleDevice, v)
-	}
+	throttleDevice = append(throttleDevice, t.values...)
 
 	return throttleDevice
 }

apis/opts/config/runtime.go

@@ -47,7 +47,7 @@ func (r *Runtime) Set(val string) error {
 func (r *Runtime) String() string {
 	var str []string
 	for k := range *r.values {
-		str = append(str, fmt.Sprintf("%s", k))
+		str = append(str, k)
 	}
 
 	return fmt.Sprintf("%v", str)

apis/server/image_bridge.go

@@ -192,11 +192,8 @@ func (s *Server) saveImage(ctx context.Context, rw http.ResponseWriter, req *htt
 	defer r.Close()
 
 	output := newWriteFlusher(rw)
-	if _, err := io.Copy(output, r); err != nil {
-		return err
-	}
-
-	return nil
+	_, err = io.Copy(output, r)
+	return err
 }
 
 // getImageHistory gets image history.

cli/container.go

@@ -65,7 +65,7 @@ type container struct {
 	networks       []string
 	ports          []string
 	expose         []string
-	publicAll      bool
+	publishAll     bool
 	securityOpt    []string
 	capAdd         []string
 	capDrop        []string

cli/image_list.go

@@ -108,9 +108,9 @@ func (i *ImagesCommand) runImages(args []string) error {
 
 	for _, dimg := range dimgs {
 		if i.flagDigest {
-			display.AddRow([]string{dimg.id, dimg.name, dimg.digest, fmt.Sprintf("%s", dimg.size)})
+			display.AddRow([]string{dimg.id, dimg.name, dimg.digest, string(dimg.size)})
 		} else {
-			display.AddRow([]string{dimg.id, dimg.name, fmt.Sprintf("%s", dimg.size)})
+			display.AddRow([]string{dimg.id, dimg.name, string(dimg.size)})
 		}
 	}
 

cli/tag.go

@@ -12,7 +12,6 @@ var tagDescription = "tag command is to add tag reference for the existing image
 // TagCommand use to implement 'tag' command.
 type TagCommand struct {
 	baseCommand
-	args []string
 }
 
 // Init initialize tag command.

cli/top.go

@@ -17,7 +17,6 @@ var topDescription = "top command is to display the running processes of a conta
 // TopCommand use to implement 'top' command, it displays all processes in a container.
 type TopCommand struct {
 	baseCommand
-	args []string
 }
 
 // Init initialize top command.

cli/update.go

@@ -17,7 +17,6 @@ var updateDescription = "Update a container's configurations, including memory,
 type UpdateCommand struct {
 	baseCommand
 	container
-	image string
 }
 
 // Init initialize update command.

client/request.go

@@ -102,10 +102,8 @@ func (client *APIClient) newRequest(method, path string, query url.Values, body
 		return nil, err
 	}
 
-	if header != nil {
-		for k, v := range header {
-			req.Header[k] = v
-		}
+	for k, v := range header {
+		req.Header[k] = v
 	}
 
 	return req, err

cri/criservice.go

@@ -39,7 +39,6 @@ func RunCriService(daemonconfig *config.Config, containerMgr mgr.ContainerMgr, i
 		readyCh <- false
 		err = fmt.Errorf("failed to start CRI service: invalid CRI version %s, expected to be v1alpha1 or v1alpha2", daemonconfig.CriConfig.CriVersion)
 	}
-	return
 }
 
 // Start CRI service with CRI version: v1alpha1

cri/stream/portforward/httpstream.go

@@ -111,13 +111,6 @@ func (h *httpStreamHandler) getStreamPair(requestID string) (*httpStreamPair, bo
 	return pair, true
 }
 
-// hasStreamPair returns a bool indicating if a stream pair for requestID exists.
-func (h *httpStreamHandler) hasStreamPair(requestID string) bool {
-	_, ok := h.streamPairs.Get(requestID).Result()
-
-	return ok
-}
-
 // removeStreamPair removes the stream pair identified by requestID from streamPairs.
 func (h *httpStreamHandler) removeStreamPair(requestID string) {
 	h.streamPairs.Remove(requestID)

cri/stream/portforward/portforward.go

@@ -28,6 +28,4 @@ func ServePortForward(ctx context.Context, w http.ResponseWriter, req *http.Requ
 		logrus.Errorf("failed to serve port forward: %v", err)
 		return
 	}
-
-	return
 }

ctrd/client.go

@@ -32,8 +32,6 @@ type Client struct {
 	watch *watch
 	lock  *containerLock
 
-	rpcAddr string
-
 	// containerd grpc pool
 	pool      []scheduler.Factory
 	scheduler scheduler.Scheduler

ctrd/container.go

@@ -701,9 +701,8 @@ func (c *Client) waitContainer(ctx context.Context, id string) (types.ContainerW
 		return c.ProbeContainer(ctx, id, -1*time.Second)
 	}
 
-	var msg *Message
 	// wait for the task to exit.
-	msg = waitExit()
+	msg := waitExit()
 
 	errMsg := ""
 	err = msg.RawError()

ctrd/snapshot.go

@@ -32,10 +32,8 @@ func (c *Client) CreateSnapshot(ctx context.Context, id, ref string) error {
 	}
 
 	parent := identity.ChainID(diffIDs).String()
-	if _, err := wrapperCli.client.SnapshotService(defaultSnapshotterName).Prepare(ctx, id, parent); err != nil {
-		return err
-	}
-	return nil
+	_, err = wrapperCli.client.SnapshotService(defaultSnapshotterName).Prepare(ctx, id, parent)
+	return err
 }
 
 // GetSnapshot returns the snapshot's info by id.

daemon/config/config.go

@@ -179,7 +179,7 @@ func (cfg *Config) MergeConfigurations(flagSet *pflag.FlagSet) error {
 		return nil
 	}
 
-	fileFlags := make(map[string]interface{}, 0)
+	fileFlags := make(map[string]interface{})
 	flattenConfig(origin, fileFlags)
 
 	// check conflict in command line flags and config file

daemon/logger/jsonfile/jsonfile_read_test.go

@@ -31,7 +31,7 @@ func TestReadLogMessagesWithRemoveFileInFollowMode(t *testing.T) {
 	os.RemoveAll(f.Name())
 
 	select {
-	case _, _ = <-watcher.Msgs:
+	case <-watcher.Msgs:
 	case <-time.After(250 * time.Millisecond):
 		// NOTE: watchTimeout is 200ms
 		t.Fatal("expected watcher.Msgs has been closed after removed file, but it's still alive")
@@ -64,7 +64,7 @@ func TestReadLogMessagesForEmptyFileWithoutFollow(t *testing.T) {
 	<-time.After(100 * time.Millisecond)
 
 	select {
-	case _, _ = <-watcher.Msgs:
+	case <-watcher.Msgs:
 	case <-time.After(100 * time.Millisecond):
 		t.Fatalf("expected watcher.Msgs has been closed after removed file, but it's still alive")
 	}

daemon/logger/jsonfile/utils_test.go

@@ -8,11 +8,14 @@ import (
 	"os"
 	"reflect"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
 	"github.com/alibaba/pouch/daemon/logger"
 	"github.com/alibaba/pouch/pkg/utils"
+
+	"github.com/pkg/errors"
 )
 
 var _ logger.LogDriver = &JSONLogFile{}
@@ -133,21 +136,25 @@ func TestFollowFile(t *testing.T) {
 	// create goroutine to read the file
 	watcher := logger.NewLogWatcher()
 	waitCh := make(chan struct{})
+	errchan := make(chan error)
+	var wg sync.WaitGroup
 	defer func() {
 		watcher.Close()
 		<-waitCh
 	}()
 
 	go func() {
-		// NOTE: make sure all the goutine exits
+		wg.Add(1)
+		// NOTE: make sure all the goroutine exits
 		defer func() {
 			waitCh <- struct{}{}
 		}()
 
 		newF, err := os.Open(f.Name())
 		if err != nil {
-			t.Fatalf("unexpected error during open file for followFile: %v", err)
+			errchan <- errors.Errorf("unexpected error during open file for followFile: %v", err)
 		}
+		wg.Done()
 
 		cfg := &logger.ReadConfig{
 			Since: generateTime(t, "2018-05-09T10:00:01.1Z"),
@@ -156,6 +163,15 @@ func TestFollowFile(t *testing.T) {
 		followFile(newF, cfg, newUnmarshal, watcher)
 	}()
 
+	go func() {
+		wg.Wait()
+		close(errchan)
+	}()
+
+	if err := <-errchan; err != nil {
+		t.Fatal(err)
+	}
+
 	// should read three log message
 	for _, el := range expectedMsgs[:2] {
 		checkExpectedLogMessage(t, watcher, el)

daemon/mgr/container.go

@@ -36,7 +36,6 @@ import (
 	containerdtypes "github.com/containerd/containerd/api/types"
 	"github.com/containerd/containerd/mount"
 	"github.com/docker/go-units"
-	"github.com/docker/libnetwork"
 	"github.com/go-openapi/strfmt"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
@@ -1525,41 +1524,6 @@ func (mgr *ContainerManager) connectToNetwork(ctx context.Context, container *Co
 	return mgr.updateNetworkConfig(container, networkIDOrName, endpoint.EndpointConfig)
 }
 
-// FIXME: remove this useless functions
-func (mgr *ContainerManager) updateNetworkSettings(container *Container, n libnetwork.Network) error {
-	if container.NetworkSettings == nil {
-		container.NetworkSettings = &types.NetworkSettings{Networks: make(map[string]*types.EndpointSettings)}
-	}
-
-	if !IsHost(container.HostConfig.NetworkMode) && IsHost(n.Type()) {
-		return fmt.Errorf("container cannot be connected to host network")
-	}
-
-	for s := range container.NetworkSettings.Networks {
-		sn, err := mgr.NetworkMgr.Get(context.Background(), s)
-		if err != nil {
-			continue
-		}
-
-		if sn.Name == n.Name() {
-			// Avoid duplicate config
-			return nil
-		}
-		if !IsPrivate(sn.Type) || !IsPrivate(n.Type()) {
-			return fmt.Errorf("container sharing network namespace with another container or host cannot be connected to any other network")
-		}
-		if IsNone(sn.Name) || IsNone(n.Name()) {
-			return fmt.Errorf("container cannot be connected to multiple networks with one of the networks in none mode")
-		}
-	}
-
-	if _, ok := container.NetworkSettings.Networks[n.Name()]; !ok {
-		container.NetworkSettings.Networks[n.Name()] = new(types.EndpointSettings)
-	}
-
-	return nil
-}
-
 func (mgr *ContainerManager) initContainerIO(c *Container) (*containerio.IO, error) {
 	if io := mgr.IOs.Get(c.ID); io != nil {
 		return nil, errors.Wrap(errtypes.ErrConflict, "failed to create containerIO")
@@ -1814,7 +1778,6 @@ func (mgr *ContainerManager) resetContainerIOs(containerID string) {
 	}
 
 	io.Reset()
-	return
 }
 
 // buildContainerEndpoint builds Endpoints according to container

daemon/mgr/container_logger.go

@@ -62,5 +62,4 @@ func (mgr *ContainerManager) SetContainerLogPath(c *Container) {
 	if c.HostConfig.LogConfig.LogDriver == "json-file" {
 		c.LogPath = filepath.Join(mgr.Config.HomeDir, "containers", c.ID, "json.log")
 	}
-	return
 }

daemon/mgr/container_storage.go

@@ -736,7 +736,7 @@ func copyImageContent(source, destination string) error {
 
 		// destination directory is not exist, so mkdir for it.
 		logrus.Warnf("(%s) is not exist", destination)
-		if err := os.MkdirAll(destination, 755); err != nil && !os.IsExist(err) {
+		if err := os.MkdirAll(destination, 0755); err != nil && !os.IsExist(err) {
 			return err
 		}
 	} else if !fi.IsDir() {

daemon/mgr/container_types.go

@@ -452,7 +452,7 @@ func (c *Container) UnsetMergedDir() {
 // SetSnapshotterMeta sets snapshotter for container
 func (c *Container) SetSnapshotterMeta(mounts []mount.Mount) {
 	// TODO(ziren): now we only support overlayfs
-	data := make(map[string]string, 0)
+	data := make(map[string]string)
 	for _, opt := range mounts[0].Options {
 		if strings.HasPrefix(opt, "upperdir=") {
 			data["UpperDir"] = strings.TrimPrefix(opt, "upperdir=")

daemon/mgr/image_store.go

@@ -171,9 +171,8 @@ func (store *imageStore) Search(ref reference.Named) (digest.Digest, reference.N
 
 func (store *imageStore) searchIDs(refID string) (digest.Digest, error) {
 	var ids []digest.Digest
-	var id string
 
-	id = refID
+	id := refID
 	if !strings.HasPrefix(refID, digest.Canonical.String()) {
 		id = fmt.Sprintf("%s:%s", digest.Canonical.String(), refID)
 	}

lxcfs/lxcfs.go

@@ -44,7 +44,7 @@ func CheckLxcfsMount() error {
 			break
 		}
 	}
-	if isMount == false {
+	if !isMount {
 		return fmt.Errorf("%s is not a mount point, please run \" lxcfs %s \" before Pouchd", LxcfsHomeDir, LxcfsHomeDir)
 	}
 	return nil

pkg/archive/archive.go

@@ -50,11 +50,8 @@ func tarFromDir(src string, writer io.Writer) error {
 		defer f.Close()
 
 		// copy file data into tar writer
-		if _, err := io.Copy(tw, f); err != nil {
-			return err
-		}
-
-		return nil
+		_, err = io.Copy(tw, f)
+		return err
 	})
 }