🌱 do not use io/ioutil anymore

.golangci.yml

@@ -64,6 +64,10 @@ linters-settings:
     go: "1.18"
   stylecheck:
     go: "1.18"
+  depguard:
+    include-go-root: true
+    packages:
+      - io/ioutil # https://go.dev/doc/go1.16#ioutil
 
 issues:
   max-same-issues: 0

examples/scratch-env/main.go

@@ -18,7 +18,6 @@ package main
 
 import (
 	goflag "flag"
-	"io/ioutil"
 	"os"
 
 	flag "github.com/spf13/pflag"
@@ -83,7 +82,7 @@ func runMain() int {
 	}
 
 	// TODO(directxman12): add support for writing to a new context in an existing file
-	kubeconfigFile, err := ioutil.TempFile("", "scratch-env-kubeconfig-")
+	kubeconfigFile, err := os.CreateTemp("", "scratch-env-kubeconfig-")
 	if err != nil {
 		log.Error(err, "unable to create kubeconfig file, continuing on without it")
 		return 1

pkg/client/config/config_test.go

@@ -17,7 +17,6 @@ limitations under the License.
 package config
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -45,7 +44,7 @@ var _ = Describe("Config", func() {
 	BeforeEach(func() {
 		// create temporary directory for test case
 		var err error
-		dir, err = ioutil.TempDir("", "cr-test")
+		dir, err = os.MkdirTemp("", "cr-test")
 		Expect(err).NotTo(HaveOccurred())
 
 		// override $HOME/.kube/config
@@ -192,7 +191,7 @@ func setConfigs(tc testCase, dir string) {
 
 func createFiles(files map[string]string, dir string) error {
 	for path, data := range files {
-		if err := ioutil.WriteFile(filepath.Join(dir, path), []byte(data), 0644); err != nil { //nolint:gosec
+		if err := os.WriteFile(filepath.Join(dir, path), []byte(data), 0644); err != nil { //nolint:gosec
 			return err
 		}
 	}

pkg/config/config.go

@@ -18,7 +18,7 @@ package config
 
 import (
 	"fmt"
-	ioutil "io/ioutil"
+	"os"
 	"sync"
 
 	"k8s.io/apimachinery/pkg/runtime"
@@ -96,7 +96,7 @@ func (d *DeferredFileLoader) loadFile() {
 		return
 	}
 
-	content, err := ioutil.ReadFile(d.path)
+	content, err := os.ReadFile(d.path)
 	if err != nil {
 		d.err = fmt.Errorf("could not read file at %s", d.path)
 		return

pkg/envtest/crd.go

@@ -23,7 +23,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"time"
@@ -282,7 +281,7 @@ func renderCRDs(options *CRDInstallOptions) ([]*apiextensionsv1.CustomResourceDe
 	var (
 		err   error
 		info  os.FileInfo
-		files []os.FileInfo
+		files []string
 	)
 
 	type GVKN struct {
@@ -304,9 +303,15 @@ func renderCRDs(options *CRDInstallOptions) ([]*apiextensionsv1.CustomResourceDe
 		}
 
 		if !info.IsDir() {
-			filePath, files = filepath.Dir(path), []os.FileInfo{info}
-		} else if files, err = ioutil.ReadDir(path); err != nil {
-			return nil, err
+			filePath, files = filepath.Dir(path), []string{info.Name()}
+		} else {
+			entries, err := os.ReadDir(path)
+			if err != nil {
+				return nil, err
+			}
+			for _, e := range entries {
+				files = append(files, e.Name())
+			}
 		}
 
 		log.V(1).Info("reading CRDs from path", "path", path)
@@ -390,20 +395,20 @@ func modifyConversionWebhooks(crds []*apiextensionsv1.CustomResourceDefinition,
 }
 
 // readCRDs reads the CRDs from files and Unmarshals them into structs.
-func readCRDs(basePath string, files []os.FileInfo) ([]*apiextensionsv1.CustomResourceDefinition, error) {
+func readCRDs(basePath string, files []string) ([]*apiextensionsv1.CustomResourceDefinition, error) {
 	var crds []*apiextensionsv1.CustomResourceDefinition
 
 	// White list the file extensions that may contain CRDs
 	crdExts := sets.NewString(".json", ".yaml", ".yml")
 
 	for _, file := range files {
 		// Only parse allowlisted file types
-		if !crdExts.Has(filepath.Ext(file.Name())) {
+		if !crdExts.Has(filepath.Ext(file)) {
 			continue
 		}
 
 		// Unmarshal CRDs from file into structs
-		docs, err := readDocuments(filepath.Join(basePath, file.Name()))
+		docs, err := readDocuments(filepath.Join(basePath, file))
 		if err != nil {
 			return nil, err
 		}
@@ -420,14 +425,14 @@ func readCRDs(basePath string, files []os.FileInfo) ([]*apiextensionsv1.CustomRe
 			crds = append(crds, crd)
 		}
 
-		log.V(1).Info("read CRDs from file", "file", file.Name())
+		log.V(1).Info("read CRDs from file", "file", file)
 	}
 	return crds, nil
 }
 
 // readDocuments reads documents from file.
 func readDocuments(fp string) ([][]byte, error) {
-	b, err := ioutil.ReadFile(fp)
+	b, err := os.ReadFile(fp)
 	if err != nil {
 		return nil, err
 	}

pkg/envtest/webhook.go

@@ -16,7 +16,6 @@ package envtest
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"path/filepath"
@@ -266,7 +265,7 @@ func (o *WebhookInstallOptions) setupCA() error {
 		return fmt.Errorf("unable to set up webhook serving certs: %w", err)
 	}
 
-	localServingCertsDir, err := ioutil.TempDir("", "envtest-serving-certs-")
+	localServingCertsDir, err := os.MkdirTemp("", "envtest-serving-certs-")
 	o.LocalServingCertDir = localServingCertsDir
 	if err != nil {
 		return fmt.Errorf("unable to create directory for webhook serving certs: %w", err)
@@ -277,10 +276,10 @@ func (o *WebhookInstallOptions) setupCA() error {
 		return fmt.Errorf("unable to marshal webhook serving certs: %w", err)
 	}
 
-	if err := ioutil.WriteFile(filepath.Join(localServingCertsDir, "tls.crt"), certData, 0640); err != nil { //nolint:gosec
+	if err := os.WriteFile(filepath.Join(localServingCertsDir, "tls.crt"), certData, 0640); err != nil { //nolint:gosec
 		return fmt.Errorf("unable to write webhook serving cert to disk: %w", err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(localServingCertsDir, "tls.key"), keyData, 0640); err != nil { //nolint:gosec
+	if err := os.WriteFile(filepath.Join(localServingCertsDir, "tls.key"), keyData, 0640); err != nil { //nolint:gosec
 		return fmt.Errorf("unable to write webhook serving key to disk: %w", err)
 	}
 
@@ -359,17 +358,23 @@ func parseWebhook(options *WebhookInstallOptions) error {
 // returns slice of mutating and validating webhook configurations.
 func readWebhooks(path string) ([]*admissionv1.MutatingWebhookConfiguration, []*admissionv1.ValidatingWebhookConfiguration, error) {
 	// Get the webhook files
-	var files []os.FileInfo
+	var files []string
 	var err error
 	log.V(1).Info("reading Webhooks from path", "path", path)
 	info, err := os.Stat(path)
 	if err != nil {
 		return nil, nil, err
 	}
 	if !info.IsDir() {
-		path, files = filepath.Dir(path), []os.FileInfo{info}
-	} else if files, err = ioutil.ReadDir(path); err != nil {
-		return nil, nil, err
+		path, files = filepath.Dir(path), []string{info.Name()}
+	} else {
+		entries, err := os.ReadDir(path)
+		if err != nil {
+			return nil, nil, err
+		}
+		for _, e := range entries {
+			files = append(files, e.Name())
+		}
 	}
 
 	// file extensions that may contain Webhooks
@@ -379,12 +384,12 @@ func readWebhooks(path string) ([]*admissionv1.MutatingWebhookConfiguration, []*
 	var valHooks []*admissionv1.ValidatingWebhookConfiguration
 	for _, file := range files {
 		// Only parse allowlisted file types
-		if !resourceExtensions.Has(filepath.Ext(file.Name())) {
+		if !resourceExtensions.Has(filepath.Ext(file)) {
 			continue
 		}
 
 		// Unmarshal Webhooks from file into structs
-		docs, err := readDocuments(filepath.Join(path, file.Name()))
+		docs, err := readDocuments(filepath.Join(path, file))
 		if err != nil {
 			return nil, nil, err
 		}
@@ -422,7 +427,7 @@ func readWebhooks(path string) ([]*admissionv1.MutatingWebhookConfiguration, []*
 			}
 		}
 
-		log.V(1).Info("read webhooks from file", "file", file.Name())
+		log.V(1).Info("read webhooks from file", "file", file)
 	}
 	return mutHooks, valHooks, nil
 }

pkg/internal/testing/controlplane/apiserver.go

@@ -19,7 +19,6 @@ package controlplane
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -385,10 +384,10 @@ func (s *APIServer) populateAPIServerCerts() error {
 		return err
 	}
 
-	if err := ioutil.WriteFile(filepath.Join(s.CertDir, "apiserver.crt"), certData, 0640); err != nil { //nolint:gosec
+	if err := os.WriteFile(filepath.Join(s.CertDir, "apiserver.crt"), certData, 0640); err != nil { //nolint:gosec
 		return err
 	}
-	if err := ioutil.WriteFile(filepath.Join(s.CertDir, "apiserver.key"), keyData, 0640); err != nil { //nolint:gosec
+	if err := os.WriteFile(filepath.Join(s.CertDir, "apiserver.key"), keyData, 0640); err != nil { //nolint:gosec
 		return err
 	}
 
@@ -405,10 +404,10 @@ func (s *APIServer) populateAPIServerCerts() error {
 		return err
 	}
 
-	if err := ioutil.WriteFile(filepath.Join(s.CertDir, saCertFile), saCert, 0640); err != nil { //nolint:gosec
+	if err := os.WriteFile(filepath.Join(s.CertDir, saCertFile), saCert, 0640); err != nil { //nolint:gosec
 		return err
 	}
-	return ioutil.WriteFile(filepath.Join(s.CertDir, saKeyFile), saKey, 0640) //nolint:gosec
+	return os.WriteFile(filepath.Join(s.CertDir, saKeyFile), saKey, 0640) //nolint:gosec
 }
 
 // Stop stops this process gracefully, waits for its termination, and cleans up

pkg/internal/testing/controlplane/auth.go

@@ -18,7 +18,7 @@ package controlplane
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 
 	"k8s.io/client-go/rest"
@@ -128,7 +128,7 @@ func (c *CertAuthn) Start() error {
 		return fmt.Errorf("start called before configure")
 	}
 	caCrt := c.ca.CA.CertBytes()
-	if err := ioutil.WriteFile(c.caCrtPath(), caCrt, 0640); err != nil { //nolint:gosec
+	if err := os.WriteFile(c.caCrtPath(), caCrt, 0640); err != nil { //nolint:gosec
 		return fmt.Errorf("unable to save the client certificate CA to %s: %w", c.caCrtPath(), err)
 	}
 

pkg/internal/testing/controlplane/kubectl_test.go

@@ -17,7 +17,7 @@ limitations under the License.
 package controlplane_test
 
 import (
-	"io/ioutil"
+	"io"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -36,7 +36,7 @@ var _ = Describe("Kubectl", func() {
 		stdout, stderr, err := k.Run(args...)
 		Expect(err).NotTo(HaveOccurred())
 		Expect(stdout).To(ContainSubstring("something"))
-		bytes, err := ioutil.ReadAll(stderr)
+		bytes, err := io.ReadAll(stderr)
 		Expect(err).NotTo(HaveOccurred())
 		Expect(bytes).To(BeEmpty())
 	})

pkg/internal/testing/process/process.go

@@ -20,7 +20,6 @@ import (
 	"crypto/tls"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/url"
@@ -109,7 +108,7 @@ func (ps *State) Init(name string) error {
 	}
 
 	if ps.Dir == "" {
-		newDir, err := ioutil.TempDir("", "k8s_test_framework_")
+		newDir, err := os.MkdirTemp("", "k8s_test_framework_")
 		if err != nil {
 			return err
 		}

pkg/internal/testing/process/process_test.go

@@ -18,7 +18,6 @@ package process_test
 
 import (
 	"bytes"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/url"
@@ -297,7 +296,7 @@ var _ = Describe("Stop method", func() {
 			var err error
 
 			Expect(processState.Start(nil, nil)).To(Succeed())
-			processState.Dir, err = ioutil.TempDir("", "k8s_test_framework_")
+			processState.Dir, err = os.MkdirTemp("", "k8s_test_framework_")
 			Expect(err).NotTo(HaveOccurred())
 			processState.DirNeedsCleaning = true
 			processState.StopTimeout = 400 * time.Millisecond

pkg/leaderelection/leader_election.go

@@ -19,7 +19,6 @@ package leaderelection
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	"k8s.io/apimachinery/pkg/util/uuid"
@@ -120,7 +119,7 @@ func getInClusterNamespace() (string, error) {
 	}
 
 	// Load the namespace file and return its content
-	namespace, err := ioutil.ReadFile(inClusterNamespacePath)
+	namespace, err := os.ReadFile(inClusterNamespacePath)
 	if err != nil {
 		return "", fmt.Errorf("error reading namespace file: %w", err)
 	}

pkg/manager/manager_test.go

@@ -20,7 +20,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"path"
@@ -1186,7 +1186,7 @@ var _ = Describe("manger.Manager", func() {
 				defer resp.Body.Close()
 				Expect(resp.StatusCode).To(Equal(200))
 
-				data, err := ioutil.ReadAll(resp.Body)
+				data, err := io.ReadAll(resp.Body)
 				Expect(err).NotTo(HaveOccurred())
 				Expect(string(data)).To(ContainSubstring("%s\n%s\n%s\n",
 					`# HELP test_one test metric for testing`,
@@ -1229,7 +1229,7 @@ var _ = Describe("manger.Manager", func() {
 				defer resp.Body.Close()
 				Expect(resp.StatusCode).To(Equal(http.StatusOK))
 
-				body, err := ioutil.ReadAll(resp.Body)
+				body, err := io.ReadAll(resp.Body)
 				Expect(err).NotTo(HaveOccurred())
 				Expect(string(body)).To(Equal("Some debug info"))
 			})

pkg/webhook/admission/http.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 
 	v1 "k8s.io/api/admission/v1"
@@ -60,7 +59,7 @@ func (wh *Webhook) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 
 	defer r.Body.Close()
-	if body, err = ioutil.ReadAll(r.Body); err != nil {
+	if body, err = io.ReadAll(r.Body); err != nil {
 		wh.log.Error(err, "unable to read the body from the incoming request")
 		reviewResponse = Errored(http.StatusBadRequest, err)
 		wh.writeResponse(w, reviewResponse)