refactor: move from io/ioutil to io and os packages (#10528)

* refactor: move from io/ioutil to io and os packages
* use fs.DirEntry instead of os.FileInfo after os.ReadDir

Signed-off-by: MOREL Matthieu <matthieu.morel@cnp.fr>

.golangci.yml

@@ -16,6 +16,7 @@ linters:
     - misspell
 
 issues:
+  max-same-issues: 0
   exclude-rules:
     - path: _test.go
       linters:
@@ -29,6 +30,7 @@ linters-settings:
       - sync/atomic: "Use go.uber.org/atomic instead of sync/atomic"
       - github.com/stretchr/testify/assert: "Use github.com/stretchr/testify/require instead of github.com/stretchr/testify/assert"
       - github.com/go-kit/kit/log: "Use github.com/go-kit/log instead of github.com/go-kit/kit/log"
+      - io/ioutil: "Use corresponding 'os' or 'io' functions instead."
       - regexp: "Use github.com/grafana/regexp instead of regexp"
   errcheck:
     exclude: scripts/errcheck_excludes.txt

cmd/prometheus/main_test.go

@@ -17,7 +17,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"math"
 	"os"
 	"os/exec"
@@ -211,7 +211,7 @@ func TestWALSegmentSizeBounds(t *testing.T) {
 		stderr, err := prom.StderrPipe()
 		require.NoError(t, err)
 		go func() {
-			slurp, _ := ioutil.ReadAll(stderr)
+			slurp, _ := io.ReadAll(stderr)
 			t.Log(string(slurp))
 		}()
 
@@ -256,7 +256,7 @@ func TestMaxBlockChunkSegmentSizeBounds(t *testing.T) {
 		stderr, err := prom.StderrPipe()
 		require.NoError(t, err)
 		go func() {
-			slurp, _ := ioutil.ReadAll(stderr)
+			slurp, _ := io.ReadAll(stderr)
 			t.Log(string(slurp))
 		}()
 
@@ -445,7 +445,7 @@ func TestModeSpecificFlags(t *testing.T) {
 			stderr, err := prom.StderrPipe()
 			require.NoError(t, err)
 			go func() {
-				slurp, _ := ioutil.ReadAll(stderr)
+				slurp, _ := io.ReadAll(stderr)
 				t.Log(string(slurp))
 			}()
 

cmd/prometheus/query_log_test.go

@@ -17,7 +17,7 @@ import (
 	"bufio"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"net/url"
@@ -235,10 +235,10 @@ func (p *queryLogTest) run(t *testing.T) {
 	p.skip(t)
 
 	// Setup temporary files for this test.
-	queryLogFile, err := ioutil.TempFile("", "query")
+	queryLogFile, err := os.CreateTemp("", "query")
 	require.NoError(t, err)
 	defer os.Remove(queryLogFile.Name())
-	p.configFile, err = ioutil.TempFile("", "config")
+	p.configFile, err = os.CreateTemp("", "config")
 	require.NoError(t, err)
 	defer os.Remove(p.configFile.Name())
 
@@ -269,7 +269,7 @@ func (p *queryLogTest) run(t *testing.T) {
 	wg.Add(1)
 	defer wg.Wait()
 	go func() {
-		slurp, _ := ioutil.ReadAll(stderr)
+		slurp, _ := io.ReadAll(stderr)
 		t.Log(string(slurp))
 		wg.Done()
 	}()
@@ -333,7 +333,7 @@ func (p *queryLogTest) run(t *testing.T) {
 		return
 	}
 	// Move the file, Prometheus should still write to the old file.
-	newFile, err := ioutil.TempFile("", "newLoc")
+	newFile, err := os.CreateTemp("", "newLoc")
 	require.NoError(t, err)
 	require.NoError(t, newFile.Close())
 	defer os.Remove(newFile.Name())

cmd/promtool/debug.go

@@ -15,7 +15,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 
 	"github.com/pkg/errors"
@@ -41,7 +41,7 @@ func debugWrite(cfg debugWriterConfig) error {
 			if err != nil {
 				return errors.Wrap(err, "error executing HTTP request")
 			}
-			body, err := ioutil.ReadAll(res.Body)
+			body, err := io.ReadAll(res.Body)
 			res.Body.Close()
 			if err != nil {
 				return errors.Wrap(err, "error reading the response body")

cmd/promtool/main.go

@@ -19,7 +19,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"net/http"
 	"net/url"
@@ -541,7 +540,7 @@ func checkSDFile(filename string) ([]*targetgroup.Group, error) {
 	}
 	defer fd.Close()
 
-	content, err := ioutil.ReadAll(fd)
+	content, err := io.ReadAll(fd)
 	if err != nil {
 		return nil, err
 	}

cmd/promtool/rules_test.go

@@ -15,8 +15,8 @@ package main
 
 import (
 	"context"
-	"io/ioutil"
 	"math"
+	"os"
 	"path/filepath"
 	"testing"
 	"time"
@@ -188,7 +188,7 @@ func createSingleRuleTestFiles(path string) error {
     labels:
         testlabel11: testlabelvalue11
 `
-	return ioutil.WriteFile(path, []byte(recordingRules), 0o777)
+	return os.WriteFile(path, []byte(recordingRules), 0o777)
 }
 
 func createMultiRuleTestFiles(path string) error {
@@ -208,7 +208,7 @@ func createMultiRuleTestFiles(path string) error {
     labels:
         testlabel11: testlabelvalue13
 `
-	return ioutil.WriteFile(path, []byte(recordingRules), 0o777)
+	return os.WriteFile(path, []byte(recordingRules), 0o777)
 }
 
 // TestBackfillLabels confirms that the labels in the rule file override the labels from the metrics
@@ -236,7 +236,7 @@ func TestBackfillLabels(t *testing.T) {
     labels:
         name1: value-from-rule
 `
-	require.NoError(t, ioutil.WriteFile(path, []byte(recordingRules), 0o777))
+	require.NoError(t, os.WriteFile(path, []byte(recordingRules), 0o777))
 	errs := ruleImporter.loadGroups(ctx, []string{path})
 	for _, err := range errs {
 		require.NoError(t, err)

cmd/promtool/unittest.go

@@ -16,7 +16,6 @@ package main
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -64,7 +63,7 @@ func RulesUnitTest(queryOpts promql.LazyLoaderOpts, files ...string) int {
 func ruleUnitTest(filename string, queryOpts promql.LazyLoaderOpts) []error {
 	fmt.Println("Unit Testing: ", filename)
 
-	b, err := ioutil.ReadFile(filename)
+	b, err := os.ReadFile(filename)
 	if err != nil {
 		return []error{err}
 	}

config/config.go

@@ -15,7 +15,6 @@ package config
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -103,7 +102,7 @@ func Load(s string, expandExternalLabels bool, logger log.Logger) (*Config, erro
 
 // LoadFile parses the given YAML file into a Config.
 func LoadFile(filename string, agentMode, expandExternalLabels bool, logger log.Logger) (*Config, error) {
-	content, err := ioutil.ReadFile(filename)
+	content, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, err
 	}

config/config_test.go

@@ -16,7 +16,6 @@ package config
 import (
 	"crypto/tls"
 	"encoding/json"
-	"io/ioutil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -1510,7 +1509,7 @@ func TestBadConfigs(t *testing.T) {
 }
 
 func TestBadStaticConfigsJSON(t *testing.T) {
-	content, err := ioutil.ReadFile("testdata/static_config.bad.json")
+	content, err := os.ReadFile("testdata/static_config.bad.json")
 	require.NoError(t, err)
 	var tg targetgroup.Group
 	err = json.Unmarshal(content, &tg)
@@ -1518,7 +1517,7 @@ func TestBadStaticConfigsJSON(t *testing.T) {
 }
 
 func TestBadStaticConfigsYML(t *testing.T) {
-	content, err := ioutil.ReadFile("testdata/static_config.bad.yml")
+	content, err := os.ReadFile("testdata/static_config.bad.yml")
 	require.NoError(t, err)
 	var tg targetgroup.Group
 	err = yaml.UnmarshalStrict(content, &tg)

discovery/eureka/client.go

@@ -18,7 +18,6 @@ import (
 	"encoding/xml"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 
 	"github.com/pkg/errors"
@@ -95,7 +94,7 @@ func fetchApps(ctx context.Context, server string, client *http.Client) (*Applic
 		return nil, err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 

discovery/file/file.go

@@ -17,7 +17,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"path/filepath"
 	"strings"
@@ -376,7 +376,7 @@ func (d *Discovery) readFile(filename string) ([]*targetgroup.Group, error) {
 	}
 	defer fd.Close()
 
-	content, err := ioutil.ReadAll(fd)
+	content, err := io.ReadAll(fd)
 	if err != nil {
 		return nil, err
 	}

discovery/file/file_test.go

@@ -17,7 +17,6 @@ import (
 	"context"
 	"encoding/json"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -73,7 +72,7 @@ func (t *testRunner) copyFile(src string) string {
 func (t *testRunner) copyFileTo(src, name string) string {
 	t.Helper()
 
-	newf, err := ioutil.TempFile(t.dir, "")
+	newf, err := os.CreateTemp(t.dir, "")
 	require.NoError(t, err)
 
 	f, err := os.Open(src)
@@ -95,7 +94,7 @@ func (t *testRunner) copyFileTo(src, name string) string {
 func (t *testRunner) writeString(file, data string) {
 	t.Helper()
 
-	newf, err := ioutil.TempFile(t.dir, "")
+	newf, err := os.CreateTemp(t.dir, "")
 	require.NoError(t, err)
 
 	_, err = newf.WriteString(data)

discovery/hetzner/robot.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"strconv"
@@ -85,7 +84,7 @@ func (d *robotDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group, err
 	}
 
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
@@ -93,7 +92,7 @@ func (d *robotDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group, err
 		return nil, errors.Errorf("non 2xx status '%d' response during hetzner service discovery with role robot", resp.StatusCode)
 	}
 
-	b, err := ioutil.ReadAll(resp.Body)
+	b, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}

discovery/http/http.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -157,7 +156,7 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 		return nil, err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
@@ -171,7 +170,7 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 		return nil, errors.Errorf("unsupported content type %q", resp.Header.Get("Content-Type"))
 	}
 
-	b, err := ioutil.ReadAll(resp.Body)
+	b, err := io.ReadAll(resp.Body)
 	if err != nil {
 		failuresCount.Inc()
 		return nil, err

discovery/kubernetes/kubernetes.go

@@ -16,7 +16,7 @@ package kubernetes
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"reflect"
 	"strings"
 	"sync"
@@ -312,7 +312,7 @@ func New(l log.Logger, conf *SDConfig) (*Discovery, error) {
 		}
 
 		if conf.NamespaceDiscovery.IncludeOwnNamespace {
-			ownNamespaceContents, err := ioutil.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace")
+			ownNamespaceContents, err := os.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace")
 			if err != nil {
 				return nil, fmt.Errorf("could not determine the pod's namespace: %w", err)
 			}

discovery/marathon/marathon.go

@@ -18,10 +18,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math/rand"
 	"net"
 	"net/http"
+	"os"
 	"strconv"
 	"strings"
 	"time"
@@ -186,7 +186,7 @@ type authTokenFileRoundTripper struct {
 // newAuthTokenFileRoundTripper adds the auth token read from the file to a request.
 func newAuthTokenFileRoundTripper(tokenFile string, rt http.RoundTripper) (http.RoundTripper, error) {
 	// fail-fast if we can't read the file.
-	_, err := ioutil.ReadFile(tokenFile)
+	_, err := os.ReadFile(tokenFile)
 	if err != nil {
 		return nil, errors.Wrapf(err, "unable to read auth token file %s", tokenFile)
 	}
@@ -194,7 +194,7 @@ func newAuthTokenFileRoundTripper(tokenFile string, rt http.RoundTripper) (http.
 }
 
 func (rt *authTokenFileRoundTripper) RoundTrip(request *http.Request) (*http.Response, error) {
-	b, err := ioutil.ReadFile(rt.authTokenFile)
+	b, err := os.ReadFile(rt.authTokenFile)
 	if err != nil {
 		return nil, errors.Wrapf(err, "unable to read auth token file %s", rt.authTokenFile)
 	}
@@ -331,7 +331,7 @@ func fetchApps(ctx context.Context, client *http.Client, url string) (*appList,
 		return nil, err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
@@ -339,7 +339,7 @@ func fetchApps(ctx context.Context, client *http.Client, url string) (*appList,
 		return nil, errors.Errorf("non 2xx status '%v' response during marathon service discovery", resp.StatusCode)
 	}
 
-	b, err := ioutil.ReadAll(resp.Body)
+	b, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}

discovery/moby/mock_test.go

@@ -16,9 +16,9 @@ package moby
 import (
 	"crypto/sha1"
 	"encoding/base64"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -63,7 +63,7 @@ func (m *SDMock) Setup() {
 // HandleNodesList mocks nodes list.
 func (m *SDMock) SetupHandlers() {
 	headers := make(map[string]string)
-	rawHeaders, err := ioutil.ReadFile(filepath.Join("testdata", m.directory, "headers.yml"))
+	rawHeaders, err := os.ReadFile(filepath.Join("testdata", m.directory, "headers.yml"))
 	require.NoError(m.t, err)
 	yaml.Unmarshal(rawHeaders, &headers)
 
@@ -102,13 +102,13 @@ func (m *SDMock) SetupHandlers() {
 					f += "__" + base64.URLEncoding.EncodeToString(h.Sum(nil))[:10]
 				}
 			}
-			if response, err := ioutil.ReadFile(filepath.Join("testdata", m.directory, f+".json")); err == nil {
+			if response, err := os.ReadFile(filepath.Join("testdata", m.directory, f+".json")); err == nil {
 				w.Header().Add("content-type", "application/json")
 				w.WriteHeader(http.StatusOK)
 				w.Write(response)
 				return
 			}
-			if response, err := ioutil.ReadFile(filepath.Join("testdata", m.directory, f)); err == nil {
+			if response, err := os.ReadFile(filepath.Join("testdata", m.directory, f)); err == nil {
 				w.WriteHeader(http.StatusOK)
 				w.Write(response)
 				return

discovery/puppetdb/puppetdb.go

@@ -19,7 +19,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/url"
@@ -187,7 +186,7 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 		return nil, err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
@@ -199,7 +198,7 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 		return nil, errors.Errorf("unsupported content type %s", resp.Header.Get("Content-Type"))
 	}
 
-	b, err := ioutil.ReadAll(resp.Body)
+	b, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}

discovery/scaleway/instance_test.go

@@ -16,9 +16,9 @@ package scaleway
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"testing"
 
 	"github.com/prometheus/common/model"
@@ -127,7 +127,7 @@ func mockScalewayInstance(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
-	instance, err := ioutil.ReadFile("testdata/instance.json")
+	instance, err := os.ReadFile("testdata/instance.json")
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return

discovery/scaleway/scaleway.go

@@ -15,8 +15,8 @@ package scaleway
 
 import (
 	"context"
-	"io/ioutil"
 	"net/http"
+	"os"
 	"strings"
 	"time"
 
@@ -226,7 +226,7 @@ type authTokenFileRoundTripper struct {
 // newAuthTokenFileRoundTripper adds the auth token read from the file to a request.
 func newAuthTokenFileRoundTripper(tokenFile string, rt http.RoundTripper) (http.RoundTripper, error) {
 	// fail-fast if we can't read the file.
-	_, err := ioutil.ReadFile(tokenFile)
+	_, err := os.ReadFile(tokenFile)
 	if err != nil {
 		return nil, errors.Wrapf(err, "unable to read auth token file %s", tokenFile)
 	}
@@ -234,7 +234,7 @@ func newAuthTokenFileRoundTripper(tokenFile string, rt http.RoundTripper) (http.
 }
 
 func (rt *authTokenFileRoundTripper) RoundTrip(request *http.Request) (*http.Response, error) {
-	b, err := ioutil.ReadFile(rt.authTokenFile)
+	b, err := os.ReadFile(rt.authTokenFile)
 	if err != nil {
 		return nil, errors.Wrapf(err, "unable to read auth token file %s", rt.authTokenFile)
 	}

discovery/triton/triton.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strings"
@@ -207,11 +206,11 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 	}
 
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
-	data, err := ioutil.ReadAll(resp.Body)
+	data, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, errors.Wrap(err, "an error occurred when reading the response body")
 	}

discovery/xds/client.go

@@ -19,7 +19,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"path"
@@ -195,7 +194,7 @@ func (rc *HTTPResourceClient) Fetch(ctx context.Context) (*v3.DiscoveryResponse,
 		return nil, err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
@@ -208,7 +207,7 @@ func (rc *HTTPResourceClient) Fetch(ctx context.Context) (*v3.DiscoveryResponse,
 		return nil, fmt.Errorf("non 200 status '%d' response during xDS fetch", resp.StatusCode)
 	}
 
-	respBody, err := ioutil.ReadAll(resp.Body)
+	respBody, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}

discovery/xds/xds_test.go

@@ -16,7 +16,6 @@ package xds
 import (
 	"context"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -60,9 +59,9 @@ func createTestHTTPServer(t *testing.T, responder discoveryResponder) *httptest.
 		require.Equal(t, "application/json", r.Header.Get("Content-Type"))
 		require.Equal(t, "application/json", r.Header.Get("Accept"))
 
-		body, err := ioutil.ReadAll(r.Body)
+		body, err := io.ReadAll(r.Body)
 		defer func() {
-			_, _ = io.Copy(ioutil.Discard, r.Body)
+			_, _ = io.Copy(io.Discard, r.Body)
 			_ = r.Body.Close()
 		}()
 		require.NotEmpty(t, body)

documentation/examples/custom-sd/adapter-usage/main.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"os"
@@ -101,11 +100,11 @@ func (d *discovery) parseServiceNodes(resp *http.Response, name string) (*target
 	}
 
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
-	b, err := ioutil.ReadAll(resp.Body)
+	b, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}
@@ -168,8 +167,8 @@ func (d *discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
 			continue
 		}
 
-		b, err := ioutil.ReadAll(resp.Body)
-		io.Copy(ioutil.Discard, resp.Body)
+		b, err := io.ReadAll(resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 		if err != nil {
 			level.Error(d.logger).Log("msg", "Error reading services list", "err", err)

documentation/examples/custom-sd/adapter/adapter.go

@@ -18,7 +18,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -117,7 +116,7 @@ func (a *Adapter) writeOutput() error {
 	b, _ := json.MarshalIndent(arr, "", "    ")
 
 	dir, _ := filepath.Split(a.output)
-	tmpfile, err := ioutil.TempFile(dir, "sd-adapter")
+	tmpfile, err := os.CreateTemp(dir, "sd-adapter")
 	if err != nil {
 		return err
 	}

documentation/examples/custom-sd/adapter/adapter_test.go

@@ -15,7 +15,6 @@ package adapter
 
 import (
 	"context"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -223,7 +222,7 @@ func TestGenerateTargetGroups(t *testing.T) {
 // TestWriteOutput checks the adapter can write a file to disk.
 func TestWriteOutput(t *testing.T) {
 	ctx := context.Background()
-	tmpfile, err := ioutil.TempFile("", "sd_adapter_test")
+	tmpfile, err := os.CreateTemp("", "sd_adapter_test")
 	require.NoError(t, err)
 	defer os.Remove(tmpfile.Name())
 	tmpfile.Close()

documentation/examples/remote_storage/remote_storage_adapter/influxdb/client_test.go

@@ -14,7 +14,7 @@
 package influxdb
 
 import (
-	"io/ioutil"
+	"io"
 	"math"
 	"net/http"
 	"net/http/httptest"
@@ -76,7 +76,7 @@ testmetric,test_label=test_label_value2 value=5.1234 123456789123
 		func(w http.ResponseWriter, r *http.Request) {
 			require.Equal(t, "POST", r.Method, "Unexpected method.")
 			require.Equal(t, "/write", r.URL.Path, "Unexpected path.")
-			b, err := ioutil.ReadAll(r.Body)
+			b, err := io.ReadAll(r.Body)
 			require.NoError(t, err, "Error reading body.")
 			require.Equal(t, expectedBody, string(b), "Unexpected request body.")
 		},

documentation/examples/remote_storage/remote_storage_adapter/main.go

@@ -16,7 +16,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	_ "net/http/pprof"
 	"net/url"
@@ -234,7 +234,7 @@ func serve(logger log.Logger, addr string, writers []writer, readers []reader) e
 	})
 
 	http.HandleFunc("/read", func(w http.ResponseWriter, r *http.Request) {
-		compressed, err := ioutil.ReadAll(r.Body)
+		compressed, err := io.ReadAll(r.Body)
 		if err != nil {
 			level.Error(logger).Log("msg", "Read error", "err", err.Error())
 			http.Error(w, err.Error(), http.StatusInternalServerError)

documentation/examples/remote_storage/remote_storage_adapter/opentsdb/client.go

@@ -18,7 +18,6 @@ import (
 	"context"
 	"encoding/json"
 	"io"
-	"io/ioutil"
 	"math"
 	"net/http"
 	"net/url"
@@ -116,7 +115,7 @@ func (c *Client) Write(samples model.Samples) error {
 		return err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 
@@ -128,7 +127,7 @@ func (c *Client) Write(samples model.Samples) error {
 
 	// API returns status code 400 on error, encoding error details in the
 	// response content in JSON.
-	buf, err = ioutil.ReadAll(resp.Body)
+	buf, err = io.ReadAll(resp.Body)
 	if err != nil {
 		return err
 	}

model/rulefmt/rulefmt.go

@@ -17,7 +17,7 @@ import (
 	"bytes"
 	"context"
 	"io"
-	"io/ioutil"
+	"os"
 	"strings"
 	"time"
 
@@ -304,7 +304,7 @@ func Parse(content []byte) (*RuleGroups, []error) {
 
 // ParseFile reads and parses rules from a file.
 func ParseFile(file string) (*RuleGroups, []error) {
-	b, err := ioutil.ReadFile(file)
+	b, err := os.ReadFile(file)
 	if err != nil {
 		return nil, []error{errors.Wrap(err, file)}
 	}

model/textparse/promparse_test.go

@@ -17,7 +17,6 @@ import (
 	"bytes"
 	"compress/gzip"
 	"io"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -361,7 +360,7 @@ func BenchmarkParse(b *testing.B) {
 			require.NoError(b, err)
 			defer f.Close()
 
-			buf, err := ioutil.ReadAll(f)
+			buf, err := io.ReadAll(f)
 			require.NoError(b, err)
 
 			b.Run(parserName+"/no-decode-metric/"+fn, func(b *testing.B) {
@@ -501,7 +500,7 @@ func BenchmarkGzip(b *testing.B) {
 			require.NoError(b, err)
 			require.NoError(b, gw.Close())
 
-			gbuf, err := ioutil.ReadAll(&buf)
+			gbuf, err := io.ReadAll(&buf)
 			require.NoError(b, err)
 
 			k := b.N / promtestdataSampleCount
@@ -516,7 +515,7 @@ func BenchmarkGzip(b *testing.B) {
 				gr, err := gzip.NewReader(bytes.NewReader(gbuf))
 				require.NoError(b, err)
 
-				d, err := ioutil.ReadAll(gr)
+				d, err := io.ReadAll(gr)
 				require.NoError(b, err)
 				require.NoError(b, gr.Close())
 

notifier/notifier.go

@@ -19,7 +19,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/url"
@@ -583,7 +582,7 @@ func (n *Manager) sendOne(ctx context.Context, c *http.Client, url string, b []b
 		return err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 

notifier/notifier_test.go

@@ -18,7 +18,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -126,7 +126,7 @@ func TestHandlerSendAll(t *testing.T) {
 				return
 			}
 
-			b, err := ioutil.ReadAll(r.Body)
+			b, err := io.ReadAll(r.Body)
 			if err != nil {
 				err = errors.Errorf("error reading body: %v", err)
 				w.WriteHeader(http.StatusInternalServerError)
@@ -221,7 +221,7 @@ func TestCustomDo(t *testing.T) {
 	h := NewManager(&Options{
 		Do: func(_ context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
 			received = true
-			body, err := ioutil.ReadAll(req.Body)
+			body, err := io.ReadAll(req.Body)
 
 			require.NoError(t, err)
 
@@ -230,7 +230,7 @@ func TestCustomDo(t *testing.T) {
 			require.Equal(t, testURL, req.URL.String())
 
 			return &http.Response{
-				Body: ioutil.NopCloser(bytes.NewBuffer(nil)),
+				Body: io.NopCloser(bytes.NewBuffer(nil)),
 			}, nil
 		},
 	}, nil)
@@ -331,7 +331,7 @@ func TestHandlerQueuing(t *testing.T) {
 		case expected := <-expectedc:
 			var alerts []*Alert
 
-			b, err := ioutil.ReadAll(r.Body)
+			b, err := io.ReadAll(r.Body)
 			if err != nil {
 				panic(err)
 			}

plugins/generate.go

@@ -18,7 +18,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"path"
@@ -30,7 +29,7 @@ import (
 //go:generate go run generate.go
 
 func main() {
-	data, err := ioutil.ReadFile(filepath.Join("..", "plugins.yml"))
+	data, err := os.ReadFile(filepath.Join("..", "plugins.yml"))
 	if err != nil {
 		log.Fatal(err)
 	}

promql/engine_test.go

@@ -16,7 +16,6 @@ package promql
 import (
 	"context"
 	"errors"
-	"io/ioutil"
 	"os"
 	"sort"
 	"testing"
@@ -42,7 +41,7 @@ func TestMain(m *testing.M) {
 func TestQueryConcurrency(t *testing.T) {
 	maxConcurrency := 10
 
-	dir, err := ioutil.TempDir("", "test_concurrency")
+	dir, err := os.MkdirTemp("", "test_concurrency")
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 	queryTracker := NewActiveQueryTracker(dir, maxConcurrency, nil)

promql/query_logger_test.go

@@ -15,7 +15,6 @@ package promql
 
 import (
 	"context"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -105,7 +104,7 @@ func TestIndexReuse(t *testing.T) {
 }
 
 func TestMMapFile(t *testing.T) {
-	file, err := ioutil.TempFile("", "mmapedFile")
+	file, err := os.CreateTemp("", "mmapedFile")
 	require.NoError(t, err)
 
 	filename := file.Name()

promql/test.go

@@ -16,8 +16,8 @@ package promql
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"math"
+	"os"
 	"strconv"
 	"strings"
 	"time"
@@ -78,7 +78,7 @@ func NewTest(t testutil.T, input string) (*Test, error) {
 }
 
 func newTestFromFile(t testutil.T, filename string) (*Test, error) {
-	content, err := ioutil.ReadFile(filename)
+	content, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, err
 	}

rules/manager_test.go

@@ -16,7 +16,6 @@ package rules
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"os"
 	"sort"
@@ -752,7 +751,7 @@ func TestUpdate(t *testing.T) {
 	rgs, errs := rulefmt.ParseFile("fixtures/rules.yaml")
 	require.Equal(t, 0, len(errs), "file parsing failures")
 
-	tmpFile, err := ioutil.TempFile("", "rules.test.*.yaml")
+	tmpFile, err := os.CreateTemp("", "rules.test.*.yaml")
 	require.NoError(t, err)
 	defer os.Remove(tmpFile.Name())
 	defer tmpFile.Close()

scrape/scrape.go

@@ -20,7 +20,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"net/http"
 	"reflect"
@@ -773,7 +772,7 @@ func (s *targetScraper) scrape(ctx context.Context, w io.Writer) (string, error)
 		return "", err
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 

scrape/scrape_test.go

@@ -19,7 +19,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"net/http"
 	"net/http/httptest"
@@ -2129,7 +2128,7 @@ func TestTargetScrapeScrapeCancel(t *testing.T) {
 	}()
 
 	go func() {
-		_, err := ts.scrape(ctx, ioutil.Discard)
+		_, err := ts.scrape(ctx, io.Discard)
 		if err == nil {
 			errc <- errors.New("Expected error but got nil")
 		} else if ctx.Err() != context.Canceled {
@@ -2173,7 +2172,7 @@ func TestTargetScrapeScrapeNotFound(t *testing.T) {
 		client: http.DefaultClient,
 	}
 
-	_, err = ts.scrape(context.Background(), ioutil.Discard)
+	_, err = ts.scrape(context.Background(), io.Discard)
 	require.Contains(t, err.Error(), "404", "Expected \"404 NotFound\" error but got: %s", err)
 }
 

scrape/target_test.go

@@ -17,10 +17,10 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"os"
 	"strings"
 	"testing"
 	"time"
@@ -337,7 +337,7 @@ func TestNewHTTPWithBadServerName(t *testing.T) {
 func newTLSConfig(certName string, t *testing.T) *tls.Config {
 	tlsConfig := &tls.Config{}
 	caCertPool := x509.NewCertPool()
-	caCert, err := ioutil.ReadFile(caCertPath)
+	caCert, err := os.ReadFile(caCertPath)
 	if err != nil {
 		t.Fatalf("Couldn't set up TLS server: %v", err)
 	}

scripts/errcheck_excludes.txt

@@ -1,4 +1,4 @@
-// Don't flag lines such as "io.Copy(ioutil.Discard, resp.Body)".
+// Don't flag lines such as "io.Copy(io.Discard, resp.Body)".
 io.Copy
 // The next two are used in HTTP handlers, any error is handled by the server itself.
 io.WriteString

storage/remote/client.go

@@ -19,7 +19,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"strconv"
 	"strings"
@@ -213,7 +212,7 @@ func (c *Client) Store(ctx context.Context, req []byte) error {
 		return RecoverableError{err, defaultBackoff}
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, httpResp.Body)
+		io.Copy(io.Discard, httpResp.Body)
 		httpResp.Body.Close()
 	}()
 
@@ -300,13 +299,13 @@ func (c *Client) Read(ctx context.Context, query *prompb.Query) (*prompb.QueryRe
 		return nil, errors.Wrap(err, "error sending request")
 	}
 	defer func() {
-		io.Copy(ioutil.Discard, httpResp.Body)
+		io.Copy(io.Discard, httpResp.Body)
 		httpResp.Body.Close()
 	}()
 	c.readQueriesDuration.Observe(time.Since(start).Seconds())
 	c.readQueriesTotal.WithLabelValues(strconv.Itoa(httpResp.StatusCode)).Inc()
 
-	compressed, err = ioutil.ReadAll(httpResp.Body)
+	compressed, err = io.ReadAll(httpResp.Body)
 	if err != nil {
 		return nil, errors.Wrap(err, fmt.Sprintf("error reading response. HTTP status code: %s", httpResp.Status))
 	}

storage/remote/codec.go

@@ -16,7 +16,6 @@ package remote
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"sort"
 	"strings"
@@ -52,7 +51,7 @@ func (e HTTPError) Status() int {
 
 // DecodeReadRequest reads a remote.Request from a http.Request.
 func DecodeReadRequest(r *http.Request) (*prompb.ReadRequest, error) {
-	compressed, err := ioutil.ReadAll(io.LimitReader(r.Body, decodeReadLimit))
+	compressed, err := io.ReadAll(io.LimitReader(r.Body, decodeReadLimit))
 	if err != nil {
 		return nil, err
 	}
@@ -524,7 +523,7 @@ func metricTypeToMetricTypeProto(t textparse.MetricType) prompb.MetricMetadata_M
 // DecodeWriteRequest from an io.Reader into a prompb.WriteRequest, handling
 // snappy decompression.
 func DecodeWriteRequest(r io.Reader) (*prompb.WriteRequest, error) {
-	compressed, err := ioutil.ReadAll(r)
+	compressed, err := io.ReadAll(r)
 	if err != nil {
 		return nil, err
 	}

storage/remote/queue_manager_test.go

@@ -16,7 +16,6 @@ package remote
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"net/url"
 	"os"
@@ -824,7 +823,7 @@ func BenchmarkStartup(b *testing.B) {
 
 	// Find the second largest segment; we will replay up to this.
 	// (Second largest as WALWatcher will start tailing the largest).
-	dirents, err := ioutil.ReadDir(dir)
+	dirents, err := os.ReadDir(dir)
 	require.NoError(b, err)
 
 	var segments []int

storage/remote/read_handler_test.go

@@ -16,7 +16,6 @@ package remote
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -84,7 +83,7 @@ func TestSampledReadEndpoint(t *testing.T) {
 	require.Equal(t, "snappy", recorder.Result().Header.Get("Content-Encoding"))
 
 	// Decode the response.
-	compressed, err = ioutil.ReadAll(recorder.Result().Body)
+	compressed, err = io.ReadAll(recorder.Result().Body)
 	require.NoError(t, err)
 
 	uncompressed, err := snappy.Decode(nil, compressed)

storage/remote/write_handler_test.go

@@ -17,7 +17,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -128,7 +128,7 @@ func TestCommitErr(t *testing.T) {
 	handler.ServeHTTP(recorder, req)
 
 	resp := recorder.Result()
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	require.NoError(t, err)
 	require.Equal(t, http.StatusInternalServerError, resp.StatusCode)
 	require.Equal(t, "commit error\n", string(body))

tsdb/block.go

@@ -17,7 +17,6 @@ package tsdb
 import (
 	"encoding/json"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -201,7 +200,7 @@ const (
 func chunkDir(dir string) string { return filepath.Join(dir, "chunks") }
 
 func readMetaFile(dir string) (*BlockMeta, int64, error) {
-	b, err := ioutil.ReadFile(filepath.Join(dir, metaFilename))
+	b, err := os.ReadFile(filepath.Join(dir, metaFilename))
 	if err != nil {
 		return nil, 0, err
 	}
@@ -636,7 +635,7 @@ func (pb *Block) Snapshot(dir string) error {
 
 	// Hardlink the chunks
 	curChunkDir := chunkDir(pb.dir)
-	files, err := ioutil.ReadDir(curChunkDir)
+	files, err := os.ReadDir(curChunkDir)
 	if err != nil {
 		return errors.Wrap(err, "ReadDir the current chunk dir")
 	}

tsdb/blockwriter.go

@@ -15,7 +15,6 @@ package tsdb
 
 import (
 	"context"
-	"io/ioutil"
 	"math"
 	"os"
 
@@ -64,7 +63,7 @@ func NewBlockWriter(logger log.Logger, dir string, blockSize int64) (*BlockWrite
 
 // initHead creates and initialises a new TSDB head.
 func (w *BlockWriter) initHead() error {
-	chunkDir, err := ioutil.TempDir(os.TempDir(), "head")
+	chunkDir, err := os.MkdirTemp(os.TempDir(), "head")
 	if err != nil {
 		return errors.Wrap(err, "create temp dir")
 	}

tsdb/chunks/chunks.go

@@ -21,7 +21,6 @@ import (
 	"hash"
 	"hash/crc32"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -591,7 +590,7 @@ func (s *Reader) Chunk(ref ChunkRef) (chunkenc.Chunk, error) {
 }
 
 func nextSequenceFile(dir string) (string, int, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return "", 0, err
 	}
@@ -617,7 +616,7 @@ func segmentFile(baseDir string, index int) string {
 }
 
 func sequenceFiles(dir string) ([]string, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}

tsdb/chunks/head_chunks.go

@@ -19,7 +19,6 @@ import (
 	"encoding/binary"
 	"hash"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -330,7 +329,7 @@ func (cdm *ChunkDiskMapper) openMMapFiles() (returnErr error) {
 }
 
 func listChunkFiles(dir string) (map[int]string, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}

tsdb/chunks/head_chunks_test.go

@@ -16,7 +16,6 @@ package chunks
 import (
 	"encoding/binary"
 	"errors"
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"strconv"
@@ -124,7 +123,7 @@ func TestChunkDiskMapper_WriteChunk_Chunk_IterateChunks(t *testing.T) {
 	require.Equal(t, 3, len(hrw.mmappedChunkFiles), "expected 3 mmapped files, got %d", len(hrw.mmappedChunkFiles))
 	require.Equal(t, len(hrw.mmappedChunkFiles), len(hrw.closers))
 
-	actualBytes, err := ioutil.ReadFile(firstFileName)
+	actualBytes, err := os.ReadFile(firstFileName)
 	require.NoError(t, err)
 
 	// Check header of the segment file.
@@ -202,7 +201,7 @@ func TestChunkDiskMapper_Truncate(t *testing.T) {
 	verifyFiles := func(remainingFiles []int) {
 		t.Helper()
 
-		files, err := ioutil.ReadDir(hrw.dir.Name())
+		files, err := os.ReadDir(hrw.dir.Name())
 		require.NoError(t, err)
 		require.Equal(t, len(remainingFiles), len(files), "files on disk")
 		require.Equal(t, len(remainingFiles), len(hrw.mmappedChunkFiles), "hrw.mmappedChunkFiles")
@@ -320,7 +319,7 @@ func TestChunkDiskMapper_Truncate_PreservesFileSequence(t *testing.T) {
 	verifyFiles := func(remainingFiles []int) {
 		t.Helper()
 
-		files, err := ioutil.ReadDir(hrw.dir.Name())
+		files, err := os.ReadDir(hrw.dir.Name())
 		require.NoError(t, err)
 		require.Equal(t, len(remainingFiles), len(files), "files on disk")
 		require.Equal(t, len(remainingFiles), len(hrw.mmappedChunkFiles), "hrw.mmappedChunkFiles")
@@ -454,7 +453,7 @@ func TestHeadReadWriter_ReadRepairOnEmptyLastFile(t *testing.T) {
 	}
 
 	// Removed even from disk.
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	require.NoError(t, err)
 	require.Equal(t, 3, len(files))
 	for _, fi := range files {

tsdb/db.go

@@ -18,7 +18,7 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
+	"io/fs"
 	"math"
 	"os"
 	"path/filepath"
@@ -761,20 +761,20 @@ func open(dir string, l log.Logger, r prometheus.Registerer, opts *Options, rngs
 }
 
 func removeBestEffortTmpDirs(l log.Logger, dir string) error {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if os.IsNotExist(err) {
 		return nil
 	}
 	if err != nil {
 		return err
 	}
-	for _, fi := range files {
-		if isTmpDir(fi) {
-			if err := os.RemoveAll(filepath.Join(dir, fi.Name())); err != nil {
-				level.Error(l).Log("msg", "failed to delete tmp block dir", "dir", filepath.Join(dir, fi.Name()), "err", err)
+	for _, f := range files {
+		if isTmpDir(f) {
+			if err := os.RemoveAll(filepath.Join(dir, f.Name())); err != nil {
+				level.Error(l).Log("msg", "failed to delete tmp block dir", "dir", filepath.Join(dir, f.Name()), "err", err)
 				continue
 			}
-			level.Info(l).Log("msg", "Found and deleted tmp block dir", "dir", filepath.Join(dir, fi.Name()))
+			level.Info(l).Log("msg", "Found and deleted tmp block dir", "dir", filepath.Join(dir, f.Name()))
 		}
 	}
 	return nil
@@ -1717,7 +1717,7 @@ func (db *DB) CleanTombstones() (err error) {
 	return nil
 }
 
-func isBlockDir(fi os.FileInfo) bool {
+func isBlockDir(fi fs.DirEntry) bool {
 	if !fi.IsDir() {
 		return false
 	}
@@ -1726,7 +1726,7 @@ func isBlockDir(fi os.FileInfo) bool {
 }
 
 // isTmpDir returns true if the given file-info contains a block ULID or checkpoint prefix and a tmp extension.
-func isTmpDir(fi os.FileInfo) bool {
+func isTmpDir(fi fs.DirEntry) bool {
 	if !fi.IsDir() {
 		return false
 	}
@@ -1745,22 +1745,22 @@ func isTmpDir(fi os.FileInfo) bool {
 }
 
 func blockDirs(dir string) ([]string, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}
 	var dirs []string
 
-	for _, fi := range files {
-		if isBlockDir(fi) {
-			dirs = append(dirs, filepath.Join(dir, fi.Name()))
+	for _, f := range files {
+		if isBlockDir(f) {
+			dirs = append(dirs, filepath.Join(dir, f.Name()))
 		}
 	}
 	return dirs, nil
 }
 
 func sequenceFiles(dir string) ([]string, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}
@@ -1776,7 +1776,7 @@ func sequenceFiles(dir string) ([]string, error) {
 }
 
 func nextSequenceFile(dir string) (string, int, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return "", 0, err
 	}

tsdb/db_test.go

@@ -20,7 +20,6 @@ import (
 	"flag"
 	"fmt"
 	"hash/crc32"
-	"io/ioutil"
 	"math"
 	"math/rand"
 	"os"
@@ -225,7 +224,7 @@ func TestNoPanicAfterWALCorruption(t *testing.T) {
 	// it is not garbage collected.
 	// The repair deletes all WAL records after the corrupted record and these are read from the mmaped chunk.
 	{
-		walFiles, err := ioutil.ReadDir(path.Join(db.Dir(), "wal"))
+		walFiles, err := os.ReadDir(path.Join(db.Dir(), "wal"))
 		require.NoError(t, err)
 		f, err := os.OpenFile(path.Join(db.Dir(), "wal", walFiles[0].Name()), os.O_RDWR, 0o666)
 		require.NoError(t, err)
@@ -926,12 +925,14 @@ func TestWALSegmentSizeOptions(t *testing.T) {
 	tests := map[int]func(dbdir string, segmentSize int){
 		// Default Wal Size.
 		0: func(dbDir string, segmentSize int) {
-			filesAndDir, err := ioutil.ReadDir(filepath.Join(dbDir, "wal"))
+			filesAndDir, err := os.ReadDir(filepath.Join(dbDir, "wal"))
 			require.NoError(t, err)
 			files := []os.FileInfo{}
 			for _, f := range filesAndDir {
 				if !f.IsDir() {
-					files = append(files, f)
+					fi, err := f.Info()
+					require.NoError(t, err)
+					files = append(files, fi)
 				}
 			}
 			// All the full segment files (all but the last) should match the segment size option.
@@ -943,12 +944,14 @@ func TestWALSegmentSizeOptions(t *testing.T) {
 		},
 		// Custom Wal Size.
 		2 * 32 * 1024: func(dbDir string, segmentSize int) {
-			filesAndDir, err := ioutil.ReadDir(filepath.Join(dbDir, "wal"))
+			filesAndDir, err := os.ReadDir(filepath.Join(dbDir, "wal"))
 			require.NoError(t, err)
 			files := []os.FileInfo{}
 			for _, f := range filesAndDir {
 				if !f.IsDir() {
-					files = append(files, f)
+					fi, err := f.Info()
+					require.NoError(t, err)
+					files = append(files, fi)
 				}
 			}
 			require.Greater(t, len(files), 1, "current WALSegmentSize should result in more than a single WAL file.")
@@ -2706,7 +2709,7 @@ func TestChunkWriter_ReadAfterWrite(t *testing.T) {
 			}
 			require.NoError(t, chunkw.Close())
 
-			files, err := ioutil.ReadDir(tempDir)
+			files, err := os.ReadDir(tempDir)
 			require.NoError(t, err)
 			require.Equal(t, test.expSegmentsCount, len(files), "expected segments count mismatch")
 
@@ -2726,7 +2729,9 @@ func TestChunkWriter_ReadAfterWrite(t *testing.T) {
 			sizeExp += test.expSegmentsCount * chunks.SegmentHeaderSize // The segment header bytes.
 
 			for i, f := range files {
-				size := int(f.Size())
+				fi, err := f.Info()
+				require.NoError(t, err)
+				size := int(fi.Size())
 				// Verify that the segment is the same or smaller than the expected size.
 				require.GreaterOrEqual(t, chunks.SegmentHeaderSize+test.expSegmentSizes[i], size, "Segment:%v should NOT be bigger than:%v actual:%v", i, chunks.SegmentHeaderSize+test.expSegmentSizes[i], size)
 
@@ -2877,7 +2882,7 @@ func TestCompactHead(t *testing.T) {
 }
 
 func deleteNonBlocks(dbDir string) error {
-	dirs, err := ioutil.ReadDir(dbDir)
+	dirs, err := os.ReadDir(dbDir)
 	if err != nil {
 		return err
 	}
@@ -2888,7 +2893,7 @@ func deleteNonBlocks(dbDir string) error {
 			}
 		}
 	}
-	dirs, err = ioutil.ReadDir(dbDir)
+	dirs, err = os.ReadDir(dbDir)
 	if err != nil {
 		return err
 	}
@@ -2995,7 +3000,7 @@ func TestOpen_VariousBlockStates(t *testing.T) {
 	require.Equal(t, len(expectedLoadedDirs), loaded)
 	require.NoError(t, db.Close())
 
-	files, err := ioutil.ReadDir(tmpDir)
+	files, err := os.ReadDir(tmpDir)
 	require.NoError(t, err)
 
 	var ignored int

tsdb/example_test.go

@@ -16,7 +16,6 @@ package tsdb
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"os"
 	"time"
@@ -27,7 +26,7 @@ import (
 func Example() {
 	// Create a random dir to work in.  Open() doesn't require a pre-existing dir, but
 	// we want to make sure not to make a mess where we shouldn't.
-	dir, err := ioutil.TempDir("", "tsdb-test")
+	dir, err := os.MkdirTemp("", "tsdb-test")
 	noErr(err)
 
 	// Open a TSDB for reading and/or writing.

tsdb/fileutil/fileutil.go

@@ -18,7 +18,6 @@
 package fileutil
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -60,12 +59,12 @@ func CopyDirs(src, dest string) error {
 }
 
 func copyFile(src, dest string) error {
-	data, err := ioutil.ReadFile(src)
+	data, err := os.ReadFile(src)
 	if err != nil {
 		return err
 	}
 
-	err = ioutil.WriteFile(dest, data, 0o666)
+	err = os.WriteFile(dest, data, 0o666)
 	if err != nil {
 		return err
 	}

tsdb/head_test.go

@@ -17,7 +17,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"math/rand"
 	"os"
@@ -1679,7 +1678,7 @@ func TestHeadReadWriterRepair(t *testing.T) {
 		// Verify that there are 6 segment files.
 		// It should only be 6 because the last call to .CutNewFile() won't
 		// take effect without another chunk being written.
-		files, err := ioutil.ReadDir(mmappedChunksDir(dir))
+		files, err := os.ReadDir(mmappedChunksDir(dir))
 		require.NoError(t, err)
 		require.Equal(t, 6, len(files))
 
@@ -1705,7 +1704,7 @@ func TestHeadReadWriterRepair(t *testing.T) {
 	// Verify that there are 3 segment files after the repair.
 	// The segments from the corrupt segment should be removed.
 	{
-		files, err := ioutil.ReadDir(mmappedChunksDir(dir))
+		files, err := os.ReadDir(mmappedChunksDir(dir))
 		require.NoError(t, err)
 		require.Equal(t, 3, len(files))
 	}
@@ -2965,7 +2964,7 @@ func TestChunkSnapshot(t *testing.T) {
 		closeHeadAndCheckSnapshot()
 
 		// Verify that there is only 1 snapshot.
-		files, err := ioutil.ReadDir(head.opts.ChunkDirRoot)
+		files, err := os.ReadDir(head.opts.ChunkDirRoot)
 		require.NoError(t, err)
 		snapshots := 0
 		for i := len(files) - 1; i >= 0; i-- {
@@ -3028,7 +3027,7 @@ func TestSnapshotError(t *testing.T) {
 	// Corrupt the snapshot.
 	snapDir, _, _, err := LastChunkSnapshot(head.opts.ChunkDirRoot)
 	require.NoError(t, err)
-	files, err := ioutil.ReadDir(snapDir)
+	files, err := os.ReadDir(snapDir)
 	require.NoError(t, err)
 	f, err := os.OpenFile(path.Join(snapDir, files[0].Name()), os.O_RDWR, 0)
 	require.NoError(t, err)
@@ -3093,7 +3092,7 @@ func TestChunkSnapshotReplayBug(t *testing.T) {
 	cpdir := filepath.Join(dir, snapshotName)
 	require.NoError(t, os.MkdirAll(cpdir, 0o777))
 
-	err = ioutil.WriteFile(filepath.Join(cpdir, "00000000"), []byte{1, 5, 3, 5, 6, 7, 4, 2, 2}, 0o777)
+	err = os.WriteFile(filepath.Join(cpdir, "00000000"), []byte{1, 5, 3, 5, 6, 7, 4, 2, 2}, 0o777)
 	require.NoError(t, err)
 
 	opts := DefaultHeadOptions()
@@ -3264,7 +3263,7 @@ func TestReplayAfterMmapReplayError(t *testing.T) {
 		}
 	}
 
-	files, err := ioutil.ReadDir(filepath.Join(dir, "chunks_head"))
+	files, err := os.ReadDir(filepath.Join(dir, "chunks_head"))
 	require.Equal(t, 5, len(files))
 
 	// Corrupt a m-map file.
@@ -3278,7 +3277,7 @@ func TestReplayAfterMmapReplayError(t *testing.T) {
 	openHead()
 
 	// There should be less m-map files due to corruption.
-	files, err = ioutil.ReadDir(filepath.Join(dir, "chunks_head"))
+	files, err = os.ReadDir(filepath.Join(dir, "chunks_head"))
 	require.Equal(t, 2, len(files))
 
 	// Querying should not panic.

tsdb/head_wal.go

@@ -15,7 +15,6 @@ package tsdb
 
 import (
 	"fmt"
-	"io/ioutil"
 	"math"
 	"os"
 	"path/filepath"
@@ -760,7 +759,7 @@ type ChunkSnapshotStats struct {
 // LastChunkSnapshot returns the directory name and index of the most recent chunk snapshot.
 // If dir does not contain any chunk snapshots, ErrNotFound is returned.
 func LastChunkSnapshot(dir string) (string, int, int, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return "", 0, 0, err
 	}
@@ -805,7 +804,7 @@ func LastChunkSnapshot(dir string) (string, int, int, error) {
 
 // DeleteChunkSnapshots deletes all chunk snapshots in a directory below a given index.
 func DeleteChunkSnapshots(dir string, maxIndex, maxOffset int) error {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return err
 	}

tsdb/index/index.go

@@ -22,7 +22,6 @@ import (
 	"hash"
 	"hash/crc32"
 	"io"
-	"io/ioutil"
 	"math"
 	"os"
 	"path/filepath"
@@ -1109,7 +1108,7 @@ func (b realByteSlice) Sub(start, end int) ByteSlice {
 // NewReader returns a new index reader on the given byte slice. It automatically
 // handles different format versions.
 func NewReader(b ByteSlice) (*Reader, error) {
-	return newReader(b, ioutil.NopCloser(nil))
+	return newReader(b, io.NopCloser(nil))
 }
 
 // NewFileReader returns a new index reader against the given index file.

tsdb/index/index_test.go

@@ -17,7 +17,6 @@ import (
 	"context"
 	"fmt"
 	"hash/crc32"
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"path/filepath"
@@ -488,7 +487,7 @@ func TestNewFileReaderErrorNoOpenFiles(t *testing.T) {
 	dir := testutil.NewTemporaryDirectory("block", t)
 
 	idxName := filepath.Join(dir.Path(), "index")
-	err := ioutil.WriteFile(idxName, []byte("corrupted contents"), 0o666)
+	err := os.WriteFile(idxName, []byte("corrupted contents"), 0o666)
 	require.NoError(t, err)
 
 	_, err = NewFileReader(idxName)

tsdb/repair.go

@@ -16,7 +16,6 @@ package tsdb
 import (
 	"encoding/json"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 
@@ -115,7 +114,7 @@ func repairBadIndexVersion(logger log.Logger, dir string) error {
 }
 
 func readBogusMetaFile(dir string) (*BlockMeta, error) {
-	b, err := ioutil.ReadFile(filepath.Join(dir, metaFilename))
+	b, err := os.ReadFile(filepath.Join(dir, metaFilename))
 	if err != nil {
 		return nil, err
 	}

tsdb/tombstones/tombstones.go

@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"hash"
 	"hash/crc32"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -190,7 +189,7 @@ type Stone struct {
 }
 
 func ReadTombstones(dir string) (Reader, int64, error) {
-	b, err := ioutil.ReadFile(filepath.Join(dir, TombstonesFilename))
+	b, err := os.ReadFile(filepath.Join(dir, TombstonesFilename))
 	if os.IsNotExist(err) {
 		return NewMemTombstones(), 0, nil
 	} else if err != nil {

tsdb/tsdbutil/dir_locker_testutil.go

@@ -15,7 +15,6 @@ package tsdbutil
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -61,7 +60,7 @@ func TestDirLockerUsage(t *testing.T, open func(t *testing.T, data string, creat
 
 	for _, c := range cases {
 		t.Run(fmt.Sprintf("%+v", c), func(t *testing.T) {
-			tmpdir, err := ioutil.TempDir("", "test")
+			tmpdir, err := os.MkdirTemp("", "test")
 			require.NoError(t, err)
 			t.Cleanup(func() {
 				require.NoError(t, os.RemoveAll(tmpdir))
@@ -71,7 +70,7 @@ func TestDirLockerUsage(t *testing.T, open func(t *testing.T, data string, creat
 			if c.fileAlreadyExists {
 				tmpLocker, err := NewDirLocker(tmpdir, "tsdb", log.NewNopLogger(), nil)
 				require.NoError(t, err)
-				err = ioutil.WriteFile(tmpLocker.path, []byte{}, 0o644)
+				err = os.WriteFile(tmpLocker.path, []byte{}, 0o644)
 				require.NoError(t, err)
 			}
 

tsdb/wal/checkpoint.go

@@ -17,7 +17,6 @@ package wal
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"os"
 	"path/filepath"
@@ -300,7 +299,7 @@ type checkpointRef struct {
 }
 
 func listCheckpoints(dir string) (refs []checkpointRef, err error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}

tsdb/wal/checkpoint_test.go

@@ -16,7 +16,6 @@ package wal
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -86,7 +85,7 @@ func TestDeleteCheckpoints(t *testing.T) {
 
 	require.NoError(t, DeleteCheckpoints(dir, 2))
 
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	require.NoError(t, err)
 	fns := []string{}
 	for _, f := range files {
@@ -100,7 +99,7 @@ func TestDeleteCheckpoints(t *testing.T) {
 
 	require.NoError(t, DeleteCheckpoints(dir, 100000000))
 
-	files, err = ioutil.ReadDir(dir)
+	files, err = os.ReadDir(dir)
 	require.NoError(t, err)
 	fns = []string{}
 	for _, f := range files {
@@ -183,7 +182,7 @@ func TestCheckpoint(t *testing.T) {
 			require.NoError(t, DeleteCheckpoints(w.Dir(), 106))
 
 			// Only the new checkpoint should be left.
-			files, err := ioutil.ReadDir(dir)
+			files, err := os.ReadDir(dir)
 			require.NoError(t, err)
 			require.Equal(t, 1, len(files))
 			require.Equal(t, "checkpoint.00000106", files[0].Name())

tsdb/wal/reader_test.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"hash/crc32"
 	"io"
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"path/filepath"
@@ -203,7 +202,7 @@ func TestReader_Live(t *testing.T) {
 
 	for i := range testReaderCases {
 		t.Run(strconv.Itoa(i), func(t *testing.T) {
-			writeFd, err := ioutil.TempFile("", "TestReader_Live")
+			writeFd, err := os.CreateTemp("", "TestReader_Live")
 			require.NoError(t, err)
 			defer os.Remove(writeFd.Name())
 

tsdb/wal/wal.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"hash/crc32"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -802,7 +801,7 @@ type segmentRef struct {
 }
 
 func listSegments(dir string) (refs []segmentRef, err error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}

tsdb/wal/watcher.go

@@ -16,7 +16,6 @@ package wal
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"os"
 	"path"
@@ -305,7 +304,7 @@ func (w *Watcher) firstAndLast() (int, int, error) {
 // Copied from tsdb/wal/wal.go so we do not have to open a WAL.
 // Plan is to move WAL watcher to TSDB and dedupe these implementations.
 func (w *Watcher) segments(dir string) ([]int, error) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}

tsdb/wal_test.go

@@ -19,7 +19,6 @@ package tsdb
 import (
 	"encoding/binary"
 	"io"
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"path"
@@ -294,7 +293,7 @@ func TestWALRestoreCorrupted_invalidSegment(t *testing.T) {
 	require.NoError(t, err)
 	defer func(wal *SegmentWAL) { require.NoError(t, wal.Close()) }(wal)
 
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 	require.NoError(t, err)
 	fns := []string{}
 	for _, f := range files {

util/httputil/compression_test.go

@@ -17,7 +17,7 @@ import (
 	"bytes"
 	"compress/gzip"
 	"compress/zlib"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -64,7 +64,7 @@ func TestCompressionHandler_PlainText(t *testing.T) {
 	resp, err := client.Get(server.URL + "/foo_endpoint")
 	require.NoError(t, err, "client get failed with unexpected error")
 	defer resp.Body.Close()
-	contents, err := ioutil.ReadAll(resp.Body)
+	contents, err := io.ReadAll(resp.Body)
 	require.NoError(t, err, "unexpected error while creating the response body reader")
 
 	expected := "Hello World!"

util/logging/file_test.go

@@ -14,7 +14,6 @@
 package logging
 
 import (
-	"io/ioutil"
 	"os"
 	"strings"
 	"testing"
@@ -24,7 +23,7 @@ import (
 )
 
 func TestJSONFileLogger_basic(t *testing.T) {
-	f, err := ioutil.TempFile("", "logging")
+	f, err := os.CreateTemp("", "logging")
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, f.Close())
@@ -53,7 +52,7 @@ func TestJSONFileLogger_basic(t *testing.T) {
 }
 
 func TestJSONFileLogger_parallel(t *testing.T) {
-	f, err := ioutil.TempFile("", "logging")
+	f, err := os.CreateTemp("", "logging")
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, f.Close())

util/teststorage/storage.go

@@ -14,7 +14,6 @@
 package teststorage
 
 import (
-	"io/ioutil"
 	"os"
 	"time"
 
@@ -31,7 +30,7 @@ import (
 // New returns a new TestStorage for testing purposes
 // that removes all associated files on closing.
 func New(t testutil.T) *TestStorage {
-	dir, err := ioutil.TempDir("", "test_storage")
+	dir, err := os.MkdirTemp("", "test_storage")
 	require.NoError(t, err, "unexpected error while opening test directory")
 
 	// Tests just load data for a series sequentially. Thus we

util/testutil/directory.go

@@ -16,7 +16,6 @@ package testutil
 import (
 	"crypto/sha256"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -120,7 +119,7 @@ func NewTemporaryDirectory(name string, t T) (handler TemporaryDirectory) {
 		err       error
 	)
 
-	directory, err = ioutil.TempDir(defaultDirectory, name)
+	directory, err = os.MkdirTemp(defaultDirectory, name)
 	require.NoError(t, err)
 
 	handler = temporaryDirectory{

web/api/v1/api_test.go

@@ -17,7 +17,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"math"
 	"net/http"
 	"net/http/httptest"
@@ -2288,7 +2288,7 @@ func (f *fakeDB) CleanTombstones() error                               { return
 func (f *fakeDB) Delete(mint, maxt int64, ms ...*labels.Matcher) error { return f.err }
 func (f *fakeDB) Snapshot(dir string, withHead bool) error             { return f.err }
 func (f *fakeDB) Stats(statsByLabelName string) (_ *tsdb.Stats, retErr error) {
-	dbDir, err := ioutil.TempDir("", "tsdb-api-ready")
+	dbDir, err := os.MkdirTemp("", "tsdb-api-ready")
 	if err != nil {
 		return nil, err
 	}
@@ -2501,7 +2501,7 @@ func TestRespondSuccess(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Error on test request: %s", err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	defer resp.Body.Close()
 	if err != nil {
 		t.Fatalf("Error reading response body: %s", err)
@@ -2537,7 +2537,7 @@ func TestRespondError(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Error on test request: %s", err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	defer resp.Body.Close()
 	if err != nil {
 		t.Fatalf("Error reading response body: %s", err)
@@ -2893,7 +2893,7 @@ func TestRespond(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Error on test request: %s", err)
 		}
-		body, err := ioutil.ReadAll(resp.Body)
+		body, err := io.ReadAll(resp.Body)
 		defer resp.Body.Close()
 		if err != nil {
 			t.Fatalf("Error reading response body: %s", err)

web/web.go

@@ -19,7 +19,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	stdlog "log"
 	"math"
 	"net"
@@ -386,7 +385,7 @@ func New(logger log.Logger, o *Options) *Handler {
 			return
 		}
 		defer func() { _ = f.Close() }()
-		idx, err := ioutil.ReadAll(f)
+		idx, err := io.ReadAll(f)
 		if err != nil {
 			w.WriteHeader(http.StatusInternalServerError)
 			fmt.Fprintf(w, "Error reading React index.html: %v", err)
@@ -615,7 +614,7 @@ func (h *Handler) consoles(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	defer file.Close()
-	text, err := ioutil.ReadAll(file)
+	text, err := io.ReadAll(file)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return

web/web_test.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -578,7 +577,7 @@ func TestAgentAPIEndPoints(t *testing.T) {
 }
 
 func cleanupTestResponse(t *testing.T, resp *http.Response) {
-	_, err := io.Copy(ioutil.Discard, resp.Body)
+	_, err := io.Copy(io.Discard, resp.Body)
 	require.NoError(t, err)
 	require.NoError(t, resp.Body.Close())
 }
@@ -589,7 +588,7 @@ func cleanupSnapshot(t *testing.T, dbDir string, resp *http.Response) {
 			Name string `json:"name"`
 		} `json:"data"`
 	}{}
-	b, err := ioutil.ReadAll(resp.Body)
+	b, err := io.ReadAll(resp.Body)
 	require.NoError(t, err)
 	require.NoError(t, json.Unmarshal(b, snapshot))
 	require.NotZero(t, snapshot.Data.Name, "snapshot directory not returned")