chore: replace usages of ioutil (#1792)

Author: donuts-are-good

pkg/api/metrics/metrics_test.go

@@ -2,18 +2,18 @@ package metrics_test
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"strings"
 	"testing"
 
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
 	"github.com/containrrr/watchtower/pkg/api"
 	metricsAPI "github.com/containrrr/watchtower/pkg/api/metrics"
 	"github.com/containrrr/watchtower/pkg/metrics"
-
-	. "github.com/onsi/ginkgo"
-	. "github.com/onsi/gomega"
 )
 
 const (
@@ -36,7 +36,7 @@ func getWithToken(handler http.Handler) map[string]string {
 	handler.ServeHTTP(respWriter, req)
 
 	res := respWriter.Result()
-	body, _ := ioutil.ReadAll(res.Body)
+	body, _ := io.ReadAll(res.Body)
 
 	for _, line := range strings.Split(string(body), "\n") {
 		if len(line) < 1 || line[0] == '#' {

pkg/container/client.go

@@ -3,21 +3,21 @@ package container
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"strings"
 	"time"
 
-	"github.com/containrrr/watchtower/pkg/registry"
-	"github.com/containrrr/watchtower/pkg/registry/digest"
-
-	t "github.com/containrrr/watchtower/pkg/types"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/api/types/network"
 	sdkClient "github.com/docker/docker/client"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
+
+	"github.com/containrrr/watchtower/pkg/registry"
+	"github.com/containrrr/watchtower/pkg/registry/digest"
+	t "github.com/containrrr/watchtower/pkg/types"
 )
 
 const defaultStopSignal = "SIGTERM"
@@ -399,7 +399,7 @@ func (client dockerClient) PullImage(ctx context.Context, container t.Container)
 
 	defer response.Close()
 	// the pull request will be aborted prematurely unless the response is read
-	if _, err = ioutil.ReadAll(response); err != nil {
+	if _, err = io.ReadAll(response); err != nil {
 		log.Error(err)
 		return err
 	}