replace deprecated ioutil APIs (#336)

client.go

@@ -6,7 +6,7 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"time"
 
@@ -100,7 +100,7 @@ func callAutograph(auth authorization, body []byte, xff string) (signedBody []by
 		return
 	}
 	defer resp.Body.Close()
-	respBody, err := ioutil.ReadAll(resp.Body)
+	respBody, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return
 	}

handlers_test.go

@@ -3,7 +3,7 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -39,7 +39,7 @@ func Test_heartbeatHandler(t *testing.T) {
 			upstreamResponse: &http.Response{
 				Status:     http.StatusText(http.StatusOK),
 				StatusCode: http.StatusOK,
-				Body:       ioutil.NopCloser(bytes.NewReader([]byte("{}"))),
+				Body:       io.NopCloser(bytes.NewReader([]byte("{}"))),
 			},
 			upstreamErr: nil,
 			expectedResponse: expectedResponse{
@@ -57,7 +57,7 @@ func Test_heartbeatHandler(t *testing.T) {
 			upstreamResponse: &http.Response{
 				Status:     http.StatusText(http.StatusBadGateway),
 				StatusCode: http.StatusBadGateway,
-				Body:       ioutil.NopCloser(bytes.NewReader([]byte("{}"))),
+				Body:       io.NopCloser(bytes.NewReader([]byte("{}"))),
 			},
 			upstreamErr: nil,
 			expectedResponse: expectedResponse{
@@ -100,7 +100,7 @@ func Test_heartbeatHandler(t *testing.T) {
 			heartbeatHandler(tt.args.baseURL, client)(w, tt.args.r)
 
 			resp := w.Result()
-			body, _ := ioutil.ReadAll(resp.Body)
+			body, _ := io.ReadAll(resp.Body)
 
 			if resp.StatusCode != tt.expectedResponse.status {
 				t.Fatalf("heartbeatHandler() returned unexpected status %v expected %v", resp.StatusCode, tt.expectedResponse.status)
@@ -122,7 +122,7 @@ func TestVersion(t *testing.T) {
 	versionHandler(w, req)
 
 	resp := w.Result()
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 
 	if resp.StatusCode != http.StatusOK {
 		t.Fatalf("returned unexpected status %v expected %v", resp.StatusCode, http.StatusOK)
@@ -141,7 +141,7 @@ func TestNotFoundHandler(t *testing.T) {
 	notFoundHandler(w, req)
 
 	resp := w.Result()
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 
 	if resp.StatusCode != http.StatusNotFound {
 		t.Fatalf("returned unexpected status %v expected %v", resp.StatusCode, http.StatusOK)

main.go

@@ -6,9 +6,9 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 
 	"github.com/pkg/errors"
@@ -153,7 +153,7 @@ func prepareServer(host string, port int) *http.Server {
 // loadFromFile reads a configuration from a local file
 func (c *configuration) loadFromFile(path string) error {
 	var confData []byte
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		return err
 	}
@@ -196,7 +196,7 @@ func httpError(w http.ResponseWriter, r *http.Request, errorCode int, errorMessa
 	// request body is read before writing a response.
 	// https://github.com/golang/go/issues/15789
 	if r.Body != nil {
-		io.Copy(ioutil.Discard, r.Body)
+		io.Copy(io.Discard, r.Body)
 		r.Body.Close()
 	}
 	http.Error(w, msg, errorCode)

main_test.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net/http"
 	"net/http/httptest"
@@ -567,7 +566,7 @@ Content-Type: application/octet-stream
 			req, err := http.NewRequest(
 				tt.method,
 				fmt.Sprintf(testServer.URL+tt.path),
-				ioutil.NopCloser(bytes.NewReader(tt.body)),
+				io.NopCloser(bytes.NewReader(tt.body)),
 			)
 			if err != nil {
 				t.Fatal(err)