refactor: move from io/ioutil to io and os packages (#858)

The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.

[1]: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <[email protected]>

Co-authored-by: Andrew Suderman <[email protected]>

Author: Juneezee

cmd/polaris/audit.go

@@ -19,7 +19,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"os"
 	"os/exec"
@@ -137,7 +137,7 @@ func ProcessHelmTemplates(helmChart, helmValues string) (string, error) {
 		return "", err
 	}
 
-	dir, err := ioutil.TempDir("", "*")
+	dir, err := os.MkdirTemp("", "*")
 	if err != nil {
 		return "", err
 	}
@@ -212,7 +212,7 @@ func outputAudit(auditData validator.AuditData, outputFile, outputURL, outputFor
 
 			defer resp.Body.Close()
 
-			body, err := ioutil.ReadAll(resp.Body)
+			body, err := io.ReadAll(resp.Body)
 
 			if err != nil {
 				logrus.Errorf("Error reading response: %v", err)
@@ -223,7 +223,7 @@ func outputAudit(auditData validator.AuditData, outputFile, outputURL, outputFor
 		}
 
 		if outputFile != "" {
-			err := ioutil.WriteFile(outputFile, []byte(outputBytes), 0644)
+			err := os.WriteFile(outputFile, []byte(outputBytes), 0644)
 			if err != nil {
 				logrus.Errorf("Error writing output to file: %v", err)
 				os.Exit(1)

cmd/polaris/fix.go

@@ -16,7 +16,6 @@ package cmd
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -93,7 +92,7 @@ var fixCommand = &cobra.Command{
 		}
 
 		for _, fullFilePath := range yamlFiles {
-			yamlContent, err := ioutil.ReadFile(fullFilePath)
+			yamlContent, err := os.ReadFile(fullFilePath)
 			if err != nil {
 				logrus.Fatalf("Error reading file with file path %s: %v", fullFilePath, err)
 			}
@@ -136,7 +135,7 @@ var fixCommand = &cobra.Command{
 			}
 
 			if updatedYamlContent != "" {
-				err = ioutil.WriteFile(fullFilePath, []byte(updatedYamlContent), 0644)
+				err = os.WriteFile(fullFilePath, []byte(updatedYamlContent), 0644)
 				if err != nil {
 					logrus.Fatalf("Error writing output to file: %v", err)
 				}

pkg/config/config.go

@@ -19,8 +19,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
+	"os"
 	"strings"
 
 	"github.com/gobuffalo/packr/v2"
@@ -70,10 +70,10 @@ func ParseFile(path string) (Configuration, error) {
 		if err2 != nil {
 			return Configuration{}, err2
 		}
-		rawBytes, err = ioutil.ReadAll(response.Body)
+		rawBytes, err = io.ReadAll(response.Body)
 	} else {
 		// path is local
-		rawBytes, err = ioutil.ReadFile(path)
+		rawBytes, err = os.ReadFile(path)
 	}
 	if err != nil {
 		return Configuration{}, err

pkg/kube/resources.go

@@ -20,7 +20,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -216,7 +215,7 @@ func CreateResourceProviderFromPath(directory string) (*ResourceProvider, error)
 		if !strings.HasSuffix(path, ".yml") && !strings.HasSuffix(path, ".yaml") {
 			return nil
 		}
-		contents, err := ioutil.ReadFile(path)
+		contents, err := os.ReadFile(path)
 		if err != nil {
 			logrus.Errorf("Error reading file: %v", path)
 			return err
@@ -427,7 +426,7 @@ func deduplicateControllers(inputResources []GenericResource) []GenericResource
 }
 
 func (resources *ResourceProvider) addResourcesFromReader(reader io.Reader) error {
-	contents, err := ioutil.ReadAll(reader)
+	contents, err := io.ReadAll(reader)
 	if err != nil {
 		logrus.Errorf("Error reading from %v: %v", reader, err)
 		return err

pkg/kube/resources_test.go

@@ -17,7 +17,7 @@ package kube
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
+	"os"
 	"testing"
 	"time"
 
@@ -78,7 +78,7 @@ func TestGetMultipleResourceFromBadFile(t *testing.T) {
 }
 
 func TestAddResourcesFromReader(t *testing.T) {
-	contents, err := ioutil.ReadFile("./test_files/test_2/multi.yaml")
+	contents, err := os.ReadFile("./test_files/test_2/multi.yaml")
 	assert.NoError(t, err)
 	reader := bytes.NewBuffer(contents)
 	resources := newResourceProvider("unknown", "Path", "-")

pkg/validator/fullaudit.go

@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"time"
 
@@ -62,7 +61,7 @@ func RunAudit(config conf.Configuration, kubeResources *kube.ResourceProvider) (
 // ReadAuditFromFile reads the data from a past audit stored in a JSON or YAML file.
 func ReadAuditFromFile(fileName string) AuditData {
 	auditData := AuditData{}
-	oldFileBytes, err := ioutil.ReadFile(fileName)
+	oldFileBytes, err := os.ReadFile(fileName)
 	if err != nil {
 		logrus.Errorf("Unable to read contents of loaded file: %v", err)
 		os.Exit(1)

test/schema_test.go

@@ -16,7 +16,6 @@ package test
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -48,7 +47,7 @@ func init() {
 	checkToTest := os.Getenv("POLARIS_CHECK_TEST")
 	_, baseDir, _, _ := runtime.Caller(0)
 	baseDir = filepath.Dir(baseDir) + "/checks"
-	dirs, err := ioutil.ReadDir(baseDir)
+	dirs, err := os.ReadDir(baseDir)
 	if err != nil {
 		panic(err)
 	}
@@ -58,13 +57,13 @@ func init() {
 			continue
 		}
 		checkDir := baseDir + "/" + check
-		cases, err := ioutil.ReadDir(checkDir)
+		cases, err := os.ReadDir(checkDir)
 		if err != nil {
 			panic(err)
 		}
 		configString := "checks:\n  " + check + ": danger"
 		checkPath := checkDir + "/check.yaml"
-		customCheckContent, err := ioutil.ReadFile(checkPath)
+		customCheckContent, err := os.ReadFile(checkPath)
 		if err == nil {
 			lines := strings.Split(string(customCheckContent), "\n")
 			for idx := range lines {