Remove use of io/ioutil package because its deprecated

Signed-off-by: Alvin Lin <[email protected]>

Author: alvinlin123

.gitignore

@@ -24,5 +24,6 @@ dist/
 Makefile.local
 
 .idea
+.vscode
 compose
 compose-simple

.golangci.yml

@@ -13,7 +13,6 @@ linters-settings:
   staticcheck:
     checks:
       - all
-      - "-SA1019" # Disable because too many file uses io/ioutil now, will fix later
   errcheck:
     # path to a file containing a list of functions to exclude from checking
     # see https://github.com/kisielk/errcheck#excluding-functions for details

cmd/cortex/main.go

@@ -5,7 +5,7 @@ import (
 	"crypto/sha256"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"math/rand"
 	"os"
 	"runtime"
@@ -204,7 +204,7 @@ func main() {
 func parseConfigFileParameter(args []string) (configFile string, expandEnv bool) {
 	// ignore errors and any output here. Any flag errors will be reported by main flag.Parse() call.
 	fs := flag.NewFlagSet("", flag.ContinueOnError)
-	fs.SetOutput(ioutil.Discard)
+	fs.SetOutput(io.Discard)
 
 	// usage not used in these functions.
 	fs.StringVar(&configFile, configFileOption, "", "")
@@ -223,7 +223,7 @@ func parseConfigFileParameter(args []string) (configFile string, expandEnv bool)
 
 // LoadConfig read YAML-formatted config from filename into cfg.
 func LoadConfig(filename string, expandENV bool, cfg *cortex.Config) error {
-	buf, err := ioutil.ReadFile(filename)
+	buf, err := os.ReadFile(filename)
 	if err != nil {
 		return errors.Wrap(err, "Error reading config file")
 	}

integration/api_endpoints_test.go

@@ -5,7 +5,7 @@ package integration
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"testing"
 
@@ -55,7 +55,7 @@ func TestConfigAPIEndpoint(t *testing.T) {
 	require.NoError(t, err)
 
 	defer runutil.ExhaustCloseWithErrCapture(&err, res.Body, "config API response")
-	body, err := ioutil.ReadAll(res.Body)
+	body, err := io.ReadAll(res.Body)
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, res.StatusCode)
 

integration/e2e/scenario_test.go

@@ -6,7 +6,7 @@ package e2e_test
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
+	"io"
 	"testing"
 	"time"
 
@@ -65,13 +65,13 @@ func testMinioWorking(t *testing.T, m *e2e.HTTPService) {
 
 	r, err := bkt.Get(ctx, "recipe")
 	require.NoError(t, err)
-	b, err = ioutil.ReadAll(r)
+	b, err = io.ReadAll(r)
 	require.NoError(t, err)
 	require.Equal(t, "Just go to Pastry Shop and buy.", string(b))
 
 	r, err = bkt.Get(ctx, "mom/recipe")
 	require.NoError(t, err)
-	b, err = ioutil.ReadAll(r)
+	b, err = io.ReadAll(r)
 	require.NoError(t, err)
 	require.Equal(t, "https://www.bbcgoodfood.com/recipes/strawberry-cheesecake-4-easy-steps", string(b))
 }

integration/e2e/service.go

@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"os/exec"
 	"regexp"
@@ -418,7 +418,7 @@ func (p *HTTPReadinessProbe) Ready(service *ConcreteService) (err error) {
 	}
 
 	defer runutil.ExhaustCloseWithErrCapture(&err, res.Body, "response readiness")
-	body, _ := ioutil.ReadAll(res.Body)
+	body, _ := io.ReadAll(res.Body)
 
 	if res.StatusCode < p.expectedStatusRangeStart || res.StatusCode > p.expectedStatusRangeEnd {
 		return fmt.Errorf("expected code in range: [%v, %v], got status code: %v and body: %v", p.expectedStatusRangeStart, p.expectedStatusRangeEnd, res.StatusCode, string(body))
@@ -534,7 +534,7 @@ func (s *HTTPService) Metrics() (_ string, err error) {
 	}
 
 	defer runutil.ExhaustCloseWithErrCapture(&err, res.Body, "metrics response")
-	body, err := ioutil.ReadAll(res.Body)
+	body, err := io.ReadAll(res.Body)
 
 	return string(body), err
 }

integration/e2e/util.go

@@ -2,7 +2,6 @@ package e2e
 
 import (
 	"context"
-	"io/ioutil"
 	"math"
 	"math/rand"
 	"net/http"
@@ -157,7 +156,7 @@ func GetTempDirectory() (string, error) {
 		}
 	}
 
-	tmpDir, err := ioutil.TempDir(dir, "e2e_integration_test")
+	tmpDir, err := os.MkdirTemp(dir, "e2e_integration_test")
 	if err != nil {
 		return "", err
 	}

integration/querier_remote_read_test.go

@@ -6,7 +6,7 @@ package integration
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"testing"
 	"time"
@@ -102,7 +102,7 @@ func TestQuerierRemoteRead(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, httpResp.StatusCode)
 
-	compressed, err = ioutil.ReadAll(httpResp.Body)
+	compressed, err = io.ReadAll(httpResp.Body)
 	require.NoError(t, err)
 
 	uncompressed, err := snappy.Decode(nil, compressed)

integration/util.go

@@ -5,7 +5,6 @@ package integration
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -44,14 +43,14 @@ func writeFileToSharedDir(s *e2e.Scenario, dst string, content []byte) error {
 		return err
 	}
 
-	return ioutil.WriteFile(
+	return os.WriteFile(
 		dst,
 		content,
 		os.ModePerm)
 }
 
 func copyFileToSharedDir(s *e2e.Scenario, src, dst string) error {
-	content, err := ioutil.ReadFile(filepath.Join(getCortexProjectDir(), src))
+	content, err := os.ReadFile(filepath.Join(getCortexProjectDir(), src))
 	if err != nil {
 		return errors.Wrapf(err, "unable to read local file %s", src)
 	}

pkg/alertmanager/alertmanager_http_test.go

@@ -2,7 +2,7 @@ package alertmanager
 
 import (
 	"context"
-	"io/ioutil"
+	"io"
 	"net/http/httptest"
 	"testing"
 	"time"
@@ -77,7 +77,7 @@ func TestMultitenantAlertmanager_GetStatusHandler(t *testing.T) {
 
 		resp := w.Result()
 		require.Equal(t, 200, w.Code)
-		body, _ := ioutil.ReadAll(resp.Body)
+		body, _ := io.ReadAll(resp.Body)
 		content := string(body)
 		require.Contains(t, content, tt.content)
 		require.NotContains(t, content, tt.nocontent)