refactor: move from io/ioutil to io and os package

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

runtime/v2/bundle.go

@@ -19,7 +19,6 @@ package v2
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 
@@ -100,7 +99,7 @@ func NewBundle(ctx context.Context, root, state, id string, spec []byte) (b *Bun
 		return nil, err
 	}
 	// write the spec to the bundle
-	err = ioutil.WriteFile(filepath.Join(b.Path, configFilename), spec, 0666)
+	err = os.WriteFile(filepath.Join(b.Path, configFilename), spec, 0666)
 	return b, err
 }
 

runtime/v2/manager.go

@@ -19,7 +19,6 @@ package v2
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 
@@ -234,7 +233,7 @@ func (m *TaskManager) Tasks(ctx context.Context, all bool) ([]runtime.Task, erro
 }
 
 func (m *TaskManager) loadExistingTasks(ctx context.Context) error {
-	nsDirs, err := ioutil.ReadDir(m.state)
+	nsDirs, err := os.ReadDir(m.state)
 	if err != nil {
 		return err
 	}
@@ -265,7 +264,7 @@ func (m *TaskManager) loadTasks(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
-	shimDirs, err := ioutil.ReadDir(filepath.Join(m.state, ns))
+	shimDirs, err := os.ReadDir(filepath.Join(m.state, ns))
 	if err != nil {
 		return err
 	}
@@ -285,7 +284,7 @@ func (m *TaskManager) loadTasks(ctx context.Context) error {
 			return err
 		}
 		// fast path
-		bf, err := ioutil.ReadDir(bundle.Path)
+		bf, err := os.ReadDir(bundle.Path)
 		if err != nil {
 			bundle.Delete()
 			log.G(ctx).WithError(err).Errorf("fast path read bundle path for %s", bundle.Path)
@@ -334,7 +333,7 @@ func (m *TaskManager) cleanupWorkDirs(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
-	dirs, err := ioutil.ReadDir(filepath.Join(m.root, ns))
+	dirs, err := os.ReadDir(filepath.Join(m.root, ns))
 	if err != nil {
 		return err
 	}

runtime/v2/runc/container.go

@@ -22,7 +22,6 @@ package runc
 import (
 	"context"
 	"encoding/json"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sync"
@@ -175,7 +174,7 @@ func ReadOptions(path string) (*options.Options, error) {
 		return nil, err
 	}
 
-	data, err := ioutil.ReadFile(filePath)
+	data, err := os.ReadFile(filePath)
 	if err != nil {
 		return nil, err
 	}
@@ -192,12 +191,12 @@ func WriteOptions(path string, opts options.Options) error {
 	if err != nil {
 		return err
 	}
-	return ioutil.WriteFile(filepath.Join(path, optionsFilename), data, 0600)
+	return os.WriteFile(filepath.Join(path, optionsFilename), data, 0600)
 }
 
 // ReadRuntime reads the runtime information from the path
 func ReadRuntime(path string) (string, error) {
-	data, err := ioutil.ReadFile(filepath.Join(path, "runtime"))
+	data, err := os.ReadFile(filepath.Join(path, "runtime"))
 	if err != nil {
 		return "", err
 	}
@@ -206,7 +205,7 @@ func ReadRuntime(path string) (string, error) {
 
 // WriteRuntime writes the runtime information into the path
 func WriteRuntime(path, runtime string) error {
-	return ioutil.WriteFile(filepath.Join(path, "runtime"), []byte(runtime), 0600)
+	return os.WriteFile(filepath.Join(path, "runtime"), []byte(runtime), 0600)
 }
 
 func newInit(ctx context.Context, path, workDir, namespace string, platform stdio.Platform,

runtime/v2/runc/util.go

@@ -22,7 +22,7 @@ package runc
 import (
 	"context"
 	"encoding/json"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 
 	"github.com/containerd/containerd/api/events"
@@ -66,7 +66,7 @@ func GetTopic(e interface{}) string {
 // there is an error reading the spec or if the container has a private PID namespace
 func ShouldKillAllOnExit(ctx context.Context, bundlePath string) bool {
 	var bundleSpec specs.Spec
-	bundleConfigContents, err := ioutil.ReadFile(filepath.Join(bundlePath, "config.json"))
+	bundleConfigContents, err := os.ReadFile(filepath.Join(bundlePath, "config.json"))
 	if err != nil {
 		log.G(ctx).WithError(err).Error("shouldKillAllOnExit: failed to read config.json")
 		return true

runtime/v2/runc/v1/service.go

@@ -21,7 +21,7 @@ package v1
 
 import (
 	"context"
-	"io/ioutil"
+	"io"
 	"os"
 	"path/filepath"
 	"sync"
@@ -180,7 +180,7 @@ func (s *service) StartShim(ctx context.Context, opts shim.StartOpts) (_ string,
 	if err := shim.WritePidFile("shim.pid", cmd.Process.Pid); err != nil {
 		return "", err
 	}
-	if data, err := ioutil.ReadAll(os.Stdin); err == nil {
+	if data, err := io.ReadAll(os.Stdin); err == nil {
 		if len(data) > 0 {
 			var any ptypes.Any
 			if err := proto.Unmarshal(data, &any); err != nil {

runtime/v2/runc/v2/service.go

@@ -22,7 +22,7 @@ package v2
 import (
 	"context"
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"os"
 	"path/filepath"
 	"sync"
@@ -245,7 +245,7 @@ func (s *service) StartShim(ctx context.Context, opts shim.StartOpts) (_ string,
 	}()
 	// make sure to wait after start
 	go cmd.Wait()
-	if data, err := ioutil.ReadAll(os.Stdin); err == nil {
+	if data, err := io.ReadAll(os.Stdin); err == nil {
 		if len(data) > 0 {
 			var any ptypes.Any
 			if err := proto.Unmarshal(data, &any); err != nil {

runtime/v2/shim.go

@@ -19,7 +19,6 @@ package v2
 import (
 	"context"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"time"
@@ -55,7 +54,7 @@ func init() {
 }
 
 func loadAddress(path string) (string, error) {
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		return "", err
 	}

runtime/v2/shim/util.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"path/filepath"
@@ -193,7 +192,7 @@ func ReadAddress(path string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		return "", err
 	}