Removing calls to deprecates io/ioutil package

.golangci.yml

@@ -33,8 +33,6 @@ issues:
     - "(method|func) [A-Z].* should be .*"
 #   Stuttering affects exported names:
     - "type name will be used as .*\\.[A-Z]{1}.* by other packages, and that stutters"
-#   TODO: Migrate away from io/ioutil
-    - "\"io/ioutil\" has been deprecated since Go 1.16"
   exclude-rules:
 #   utils/cpuload/netlink/netlink.go:102:15: Error return value of `binary.Write` is not checked (errcheck)
 #   There are more similar issues in this file

client/client.go

@@ -25,7 +25,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"path"
 	"strings"
@@ -187,7 +186,7 @@ func (c *Client) httpGetJSONData(data, postData interface{}, url, infoName strin
 		return fmt.Errorf("received empty response for %q from %q", infoName, url)
 	}
 	defer resp.Body.Close()
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		err = fmt.Errorf("unable to read all %q from %q: %v", infoName, url, err)
 		return err

client/v2/client.go

@@ -19,7 +19,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 	"path"
@@ -147,7 +147,7 @@ func (c *Client) httpGetResponse(postData interface{}, urlPath, infoName string)
 		return nil, fmt.Errorf("received empty response for %q from %q", infoName, urlPath)
 	}
 	defer resp.Body.Close()
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		err = fmt.Errorf("unable to read all %q from %q: %v", infoName, urlPath, err)
 		return nil, err

cmd/internal/storage/bigquery/client/client.go

@@ -18,7 +18,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"strings"
 
 	"golang.org/x/oauth2"
@@ -62,7 +62,7 @@ func connect() (*oauth2.Token, *bigquery.Service, error) {
 	if *pemFile == "" {
 		return nil, nil, fmt.Errorf("no credentials specified")
 	}
-	pemBytes, err := ioutil.ReadFile(*pemFile)
+	pemBytes, err := os.ReadFile(*pemFile)
 	if err != nil {
 		return nil, nil, fmt.Errorf("could not access credential file %v - %v", pemFile, err)
 	}

cmd/internal/storage/kafka/kafka.go

@@ -19,7 +19,6 @@ import (
 	"crypto/x509"
 	"encoding/json"
 	"flag"
-	"io/ioutil"
 	"log"
 	"os"
 	"strings"
@@ -110,7 +109,7 @@ func generateTLSConfig() (*tls.Config, error) {
 			return nil, err
 		}
 
-		caCert, err := ioutil.ReadFile(*caFile)
+		caCert, err := os.ReadFile(*caFile)
 		if err != nil {
 			return nil, err
 		}

collector/generic_collector.go

@@ -17,7 +17,7 @@ package collector
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"regexp"
 	"strconv"
@@ -145,7 +145,7 @@ func (collector *GenericCollector) Collect(metrics map[string][]v1.MetricVal) (t
 
 	defer response.Body.Close()
 
-	pageContent, err := ioutil.ReadAll(response.Body)
+	pageContent, err := io.ReadAll(response.Body)
 	if err != nil {
 		return nextCollectionTime, nil, err
 	}

collector/generic_collector_test.go

@@ -16,7 +16,6 @@ package collector
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -40,9 +39,9 @@ func TestEmptyConfig(t *testing.T) {
         `
 
 	// Create a temporary config file 'temp.json' with invalid json format
-	assert.NoError(ioutil.WriteFile("temp.json", []byte(emptyConfig), 0777))
+	assert.NoError(os.WriteFile("temp.json", []byte(emptyConfig), 0777))
 
-	configFile, err := ioutil.ReadFile("temp.json")
+	configFile, err := os.ReadFile("temp.json")
 	assert.NoError(err)
 
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
@@ -72,8 +71,8 @@ func TestConfigWithErrors(t *testing.T) {
 	`
 
 	// Create a temporary config file 'temp.json' with invalid json format
-	assert.NoError(ioutil.WriteFile("temp.json", []byte(invalid), 0777))
-	configFile, err := ioutil.ReadFile("temp.json")
+	assert.NoError(os.WriteFile("temp.json", []byte(invalid), 0777))
+	configFile, err := os.ReadFile("temp.json")
 	assert.NoError(err)
 
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
@@ -110,9 +109,9 @@ func TestConfigWithRegexErrors(t *testing.T) {
         `
 
 	// Create a temporary config file 'temp.json'
-	assert.NoError(ioutil.WriteFile("temp.json", []byte(invalid), 0777))
+	assert.NoError(os.WriteFile("temp.json", []byte(invalid), 0777))
 
-	configFile, err := ioutil.ReadFile("temp.json")
+	configFile, err := os.ReadFile("temp.json")
 	assert.NoError(err)
 
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
@@ -126,7 +125,7 @@ func TestConfig(t *testing.T) {
 	assert := assert.New(t)
 
 	// Create an nginx collector using the config file 'sample_config.json'
-	configFile, err := ioutil.ReadFile("config/sample_config.json")
+	configFile, err := os.ReadFile("config/sample_config.json")
 	assert.NoError(err)
 
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
@@ -139,7 +138,7 @@ func TestConfig(t *testing.T) {
 
 func TestEndpointConfig(t *testing.T) {
 	assert := assert.New(t)
-	configFile, err := ioutil.ReadFile("config/sample_config_endpoint_config.json")
+	configFile, err := os.ReadFile("config/sample_config_endpoint_config.json")
 	assert.NoError(err)
 
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
@@ -158,7 +157,7 @@ func TestMetricCollection(t *testing.T) {
 	assert := assert.New(t)
 
 	// Collect nginx metrics from a fake nginx endpoint
-	configFile, err := ioutil.ReadFile("config/sample_config.json")
+	configFile, err := os.ReadFile("config/sample_config.json")
 	assert.NoError(err)
 
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
@@ -194,7 +193,7 @@ func TestMetricCollectionLimit(t *testing.T) {
 	assert := assert.New(t)
 
 	// Collect nginx metrics from a fake nginx endpoint
-	configFile, err := ioutil.ReadFile("config/sample_config.json")
+	configFile, err := os.ReadFile("config/sample_config.json")
 	assert.NoError(err)
 
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")

collector/prometheus_collector_test.go

@@ -16,9 +16,9 @@ package collector
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -32,7 +32,7 @@ func TestPrometheus(t *testing.T) {
 	assert := assert.New(t)
 
 	// Create a prometheus collector using the config file 'sample_config_prometheus.json'
-	configFile, err := ioutil.ReadFile("config/sample_config_prometheus.json")
+	configFile, err := os.ReadFile("config/sample_config_prometheus.json")
 	assert.NoError(err)
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
 	collector, err := NewPrometheusCollector("Prometheus", configFile, 100, containerHandler, http.DefaultClient)
@@ -116,7 +116,7 @@ func TestPrometheusEndpointConfig(t *testing.T) {
 	assert := assert.New(t)
 
 	//Create a prometheus collector using the config file 'sample_config_prometheus.json'
-	configFile, err := ioutil.ReadFile("config/sample_config_prometheus_endpoint_config.json")
+	configFile, err := os.ReadFile("config/sample_config_prometheus_endpoint_config.json")
 	assert.NoError(err)
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
 	containerHandler.On("GetContainerIPAddress").Return(
@@ -133,7 +133,7 @@ func TestPrometheusShortResponse(t *testing.T) {
 	assert := assert.New(t)
 
 	// Create a prometheus collector using the config file 'sample_config_prometheus.json'
-	configFile, err := ioutil.ReadFile("config/sample_config_prometheus.json")
+	configFile, err := os.ReadFile("config/sample_config_prometheus.json")
 	assert.NoError(err)
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
 	collector, err := NewPrometheusCollector("Prometheus", configFile, 100, containerHandler, http.DefaultClient)
@@ -157,7 +157,7 @@ func TestPrometheusMetricCountLimit(t *testing.T) {
 	assert := assert.New(t)
 
 	// Create a prometheus collector using the config file 'sample_config_prometheus.json'
-	configFile, err := ioutil.ReadFile("config/sample_config_prometheus.json")
+	configFile, err := os.ReadFile("config/sample_config_prometheus.json")
 	assert.NoError(err)
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
 	collector, err := NewPrometheusCollector("Prometheus", configFile, 10, containerHandler, http.DefaultClient)
@@ -187,7 +187,7 @@ func TestPrometheusFiltersMetrics(t *testing.T) {
 	assert := assert.New(t)
 
 	// Create a prometheus collector using the config file 'sample_config_prometheus_filtered.json'
-	configFile, err := ioutil.ReadFile("config/sample_config_prometheus_filtered.json")
+	configFile, err := os.ReadFile("config/sample_config_prometheus_filtered.json")
 	assert.NoError(err)
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
 	collector, err := NewPrometheusCollector("Prometheus", configFile, 100, containerHandler, http.DefaultClient)
@@ -227,7 +227,7 @@ func TestPrometheusFiltersMetricsCountLimit(t *testing.T) {
 	assert := assert.New(t)
 
 	// Create a prometheus collector using the config file 'sample_config_prometheus_filtered.json'
-	configFile, err := ioutil.ReadFile("config/sample_config_prometheus_filtered.json")
+	configFile, err := os.ReadFile("config/sample_config_prometheus_filtered.json")
 	assert.NoError(err)
 	containerHandler := containertest.NewMockContainerHandler("mockContainer")
 	_, err = NewPrometheusCollector("Prometheus", configFile, 1, containerHandler, http.DefaultClient)

container/common/container_hints.go

@@ -21,7 +21,6 @@ package common
 import (
 	"encoding/json"
 	"flag"
-	"io/ioutil"
 	"os"
 )
 
@@ -48,7 +47,7 @@ type networkInterface struct {
 }
 
 func GetContainerHintsFromFile(containerHintsFile string) (ContainerHints, error) {
-	dat, err := ioutil.ReadFile(containerHintsFile)
+	dat, err := os.ReadFile(containerHintsFile)
 	if os.IsNotExist(err) {
 		return ContainerHints{}, nil
 	}

container/common/helpers.go

@@ -16,7 +16,6 @@ package common
 
 import (
 	"fmt"
-	"io/ioutil"
 	"math"
 	"os"
 	"path"
@@ -235,7 +234,7 @@ func readString(dirpath string, file string) string {
 	cgroupFile := path.Join(dirpath, file)
 
 	// Read
-	out, err := ioutil.ReadFile(cgroupFile)
+	out, err := os.ReadFile(cgroupFile)
 	if err != nil {
 		// Ignore non-existent files
 		if !os.IsNotExist(err) {

container/crio/client.go

@@ -18,7 +18,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"sync"
@@ -142,7 +142,7 @@ func (c *crioClientImpl) ContainerInfo(id string) (*ContainerInfo, error) {
 	// golang's http.Do doesn't return an error if non 200 response code is returned
 	// handle this case here, rather than failing to decode the body
 	if resp.StatusCode != http.StatusOK {
-		respBody, err := ioutil.ReadAll(resp.Body)
+		respBody, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return nil, fmt.Errorf("Error finding container %s: Status %d", id, resp.StatusCode)
 		}

container/docker/handler.go

@@ -17,7 +17,7 @@ package docker
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path"
 	"strconv"
 	"strings"
@@ -107,7 +107,7 @@ func getRwLayerID(containerID, storageDir string, sd storageDriver, dockerVersio
 		return containerID, nil
 	}
 
-	bytes, err := ioutil.ReadFile(path.Join(storageDir, "image", string(sd), "layerdb", "mounts", containerID, rwLayerIDFile))
+	bytes, err := os.ReadFile(path.Join(storageDir, "image", string(sd), "layerdb", "mounts", containerID, rwLayerIDFile))
 	if err != nil {
 		return "", fmt.Errorf("failed to identify the read-write layer ID for container %q. - %v", containerID, err)
 	}

container/docker/handler_test.go

@@ -16,7 +16,6 @@
 package docker
 
 import (
-	"io/ioutil"
 	"os"
 	"path"
 	"strings"
@@ -38,13 +37,13 @@ func TestStorageDirDetectionWithOldVersions(t *testing.T) {
 
 func TestStorageDirDetectionWithNewVersions(t *testing.T) {
 	as := assert.New(t)
-	testDir, err := ioutil.TempDir("", "")
+	testDir, err := os.MkdirTemp(os.TempDir(), "")
 	as.Nil(err)
 	containerID := "abcd"
 	randomizedID := "xyz"
 	randomIDPath := path.Join(testDir, "image/aufs/layerdb/mounts/", containerID)
 	as.Nil(os.MkdirAll(randomIDPath, os.ModePerm))
-	as.Nil(ioutil.WriteFile(path.Join(randomIDPath, "mount-id"), []byte(randomizedID), os.ModePerm))
+	as.Nil(os.WriteFile(path.Join(randomIDPath, "mount-id"), []byte(randomizedID), os.ModePerm))
 	rwLayer, err := getRwLayerID(containerID, testDir, "aufs", []int{1, 10, 0})
 	as.Nil(err)
 	as.Equal(rwLayer, randomizedID)