Move from io/ioutil to os package (#524)

Co-authored-by: CrazyMax <crazy-max@users.noreply.github.com>

internal/provider/file/image.go

@@ -1,7 +1,7 @@
 package file
 
 import (
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -21,7 +21,7 @@ func (c *Client) listFileImage() []model.Image {
 
 	for _, file := range files {
 		var items []model.Image
-		bytes, err := ioutil.ReadFile(file)
+		bytes, err := os.ReadFile(file)
 		if err != nil {
 			c.logger.Error().Err(err).Msgf("Unable to read config file %s", file)
 			continue
@@ -77,7 +77,7 @@ func (c *Client) getFiles() []string {
 
 	switch {
 	case len(c.config.Directory) > 0:
-		fileList, err := ioutil.ReadDir(c.config.Directory)
+		fileList, err := os.ReadDir(c.config.Directory)
 		if err != nil {
 			c.logger.Error().Err(err).Msgf("Unable to read directory %s", c.config.Directory)
 			return files

pkg/dockerfile/client.go

@@ -2,7 +2,7 @@ package dockerfile
 
 import (
 	"bytes"
-	"io/ioutil"
+	"os"
 
 	"github.com/moby/buildkit/frontend/dockerfile/instructions"
 	"github.com/moby/buildkit/frontend/dockerfile/parser"
@@ -25,7 +25,7 @@ type Options struct {
 
 // New initializes a new dockerfile client
 func New(opts Options) (*Client, error) {
-	b, err := ioutil.ReadFile(opts.Filename)
+	b, err := os.ReadFile(opts.Filename)
 	if err != nil {
 		return nil, errors.Wrapf(err, "Cannot read Dockerfile %s", opts.Filename)
 	}

pkg/k8s/client.go

@@ -2,7 +2,6 @@ package k8s
 
 import (
 	"context"
-	"io/ioutil"
 	"os"
 
 	"github.com/crazy-max/diun/v4/pkg/utl"
@@ -105,7 +104,7 @@ func newExternalClusterClient(opts Options) (*kubernetes.Clientset, error) {
 	}
 
 	if opts.CertAuthFilePath != "" {
-		caData, err := ioutil.ReadFile(opts.CertAuthFilePath)
+		caData, err := os.ReadFile(opts.CertAuthFilePath)
 		if err != nil {
 			return nil, errors.Wrap(err, "Failed to read CA file")
 		}

pkg/utl/utl.go

@@ -1,7 +1,6 @@
 package utl
 
 import (
-	"io/ioutil"
 	"os"
 	"regexp"
 	"time"
@@ -59,7 +58,7 @@ func GetSecret(plaintext, filename string) (string, error) {
 	if plaintext != "" {
 		return plaintext, nil
 	} else if filename != "" {
-		b, err := ioutil.ReadFile(filename)
+		b, err := os.ReadFile(filename)
 		if err != nil {
 			return "", err
 		}