refactor: move from io/ioutil to io and os package (#3294)

* refactor: move from io/ioutil to io and os package

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

* test(anonymizer): add test for New and SaveMapping

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

cmd/agent/app/agent_test.go

@@ -17,7 +17,7 @@ package app
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strings"
 	"testing"
@@ -66,7 +66,7 @@ func TestAgentSamplingEndpoint(t *testing.T) {
 		}
 		resp, err := http.Get(url)
 		require.NoError(t, err)
-		body, err := ioutil.ReadAll(resp.Body)
+		body, err := io.ReadAll(resp.Body)
 		assert.NoError(t, err)
 		assert.Equal(t, "collector error: no peers available\n", string(body))
 	})
@@ -77,7 +77,7 @@ func TestAgentMetricsEndpoint(t *testing.T) {
 		url := fmt.Sprintf("http://%s/metrics", httpAddr)
 		resp, err := http.Get(url)
 		require.NoError(t, err)
-		body, err := ioutil.ReadAll(resp.Body)
+		body, err := io.ReadAll(resp.Body)
 		assert.NoError(t, err)
 		assert.Contains(t, string(body), "# HELP")
 	})

cmd/all-in-one/all_in_one_test.go

@@ -21,7 +21,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"testing"
 	"time"
@@ -92,7 +92,7 @@ func getAPITrace(t *testing.T) {
 		resp, err := httpClient.Do(req)
 		require.NoError(t, err)
 
-		body, _ := ioutil.ReadAll(resp.Body)
+		body, _ := io.ReadAll(resp.Body)
 
 		err = json.Unmarshal(body, &queryResponse)
 		require.NoError(t, err)
@@ -115,7 +115,7 @@ func getSamplingStrategy(t *testing.T) {
 	resp, err := httpClient.Do(req)
 	require.NoError(t, err)
 
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 
 	err = json.Unmarshal(body, &queryResponse)
 	require.NoError(t, err)
@@ -143,7 +143,7 @@ func getServicesAPIV3(t *testing.T) {
 	require.NoError(t, err)
 	resp, err := httpClient.Do(req)
 	require.NoError(t, err)
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 
 	var servicesResponse api_v3.GetServicesResponse
 	jsonpb := runtime.JSONPb{}

cmd/anonymizer/app/anonymizer/anonymizer.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"hash/fnv"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sync"
@@ -81,7 +80,7 @@ func New(mappingFile string, options Options, logger *zap.Logger) *Anonymizer {
 		options: options,
 	}
 	if _, err := os.Stat(filepath.Clean(mappingFile)); err == nil {
-		dat, err := ioutil.ReadFile(filepath.Clean(mappingFile))
+		dat, err := os.ReadFile(filepath.Clean(mappingFile))
 		if err != nil {
 			logger.Fatal("Cannot load previous mapping", zap.Error(err))
 		}
@@ -108,7 +107,7 @@ func (a *Anonymizer) SaveMapping() {
 		a.logger.Error("Failed to marshal mapping file", zap.Error(err))
 		return
 	}
-	if err := ioutil.WriteFile(filepath.Clean(a.mappingFile), dat, os.ModePerm); err != nil {
+	if err := os.WriteFile(filepath.Clean(a.mappingFile), dat, os.ModePerm); err != nil {
 		a.logger.Error("Failed to write mapping file", zap.Error(err))
 		return
 	}

cmd/anonymizer/app/anonymizer/anonymizer_test.go

@@ -15,10 +15,13 @@
 package anonymizer
 
 import (
+	"os"
+	"path/filepath"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"go.uber.org/zap"
 
 	"github.com/jaegertracing/jaeger/model"
 )
@@ -73,6 +76,62 @@ var span2 = &model.Span{
 	StartTime: time.Unix(300, 0),
 }
 
+func TestNew(t *testing.T) {
+	nopLogger := zap.NewNop()
+	tempDir := t.TempDir()
+
+	file, err := os.CreateTemp(tempDir, "mapping.json")
+	assert.NoError(t, err)
+
+	_, err = file.Write([]byte(`
+{
+    "services": {
+		"api": "hashed_api"
+	},
+	"operations": {
+		"[api]:delete": "hashed_api_delete"
+	}
+}
+`))
+	assert.NoError(t, err)
+
+	anonymizer := New(file.Name(), Options{}, nopLogger)
+	assert.NotNil(t, anonymizer)
+}
+
+func TestAnonymizer_SaveMapping(t *testing.T) {
+	nopLogger := zap.NewNop()
+	mapping := mapping{
+		Services:   make(map[string]string),
+		Operations: make(map[string]string),
+	}
+
+	tests := []struct {
+		name        string
+		mappingFile string
+	}{
+		{
+			name:        "fail to write mapping file",
+			mappingFile: "",
+		},
+		{
+			name:        "save mapping file successfully",
+			mappingFile: filepath.Join(t.TempDir(), "mapping.json"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			anonymizer := Anonymizer{
+				logger:      nopLogger,
+				mapping:     mapping,
+				mappingFile: tt.mappingFile,
+			}
+			anonymizer.SaveMapping()
+		})
+	}
+}
+
 func TestAnonymizer_FilterStandardTags(t *testing.T) {
 	expected := []model.KeyValue{
 		model.Bool("error", true),

cmd/anonymizer/app/uiconv/extractor_test.go

@@ -15,7 +15,6 @@
 package uiconv
 
 import (
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -111,7 +110,7 @@ func TestExtractor_TraceScanError(t *testing.T) {
 }
 
 func loadJSON(t *testing.T, fileName string, i interface{}) {
-	b, err := ioutil.ReadFile(fileName)
+	b, err := os.ReadFile(fileName)
 	require.NoError(t, err)
 	err = swag.ReadJSON(b, i)
 	require.NoError(t, err, "Failed to parse json fixture file %s", fileName)

cmd/collector/app/handler/http_handler.go

@@ -18,7 +18,7 @@ package handler
 import (
 	"fmt"
 	"html"
-	"io/ioutil"
+	"io"
 	"mime"
 	"net/http"
 
@@ -62,7 +62,7 @@ func (aH *APIHandler) RegisterRoutes(router *mux.Router) {
 
 // SaveSpan submits the span provided in the request body to the JaegerBatchesHandler
 func (aH *APIHandler) SaveSpan(w http.ResponseWriter, r *http.Request) {
-	bodyBytes, err := ioutil.ReadAll(r.Body)
+	bodyBytes, err := io.ReadAll(r.Body)
 	r.Body.Close()
 	if err != nil {
 		http.Error(w, fmt.Sprintf(UnableToReadBodyErrFormat, err), http.StatusInternalServerError)

cmd/collector/app/handler/http_handler_test.go

@@ -19,7 +19,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"sync"
@@ -204,7 +204,7 @@ func postBytes(contentType, urlStr string, bodyBytes []byte) (int, string, error
 	}
 	defer res.Body.Close()
 
-	body, err := ioutil.ReadAll(res.Body)
+	body, err := io.ReadAll(res.Body)
 	if err != nil {
 		return 0, "", err
 	}

cmd/collector/app/zipkin/http_handler.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"html"
 	"io"
-	"io/ioutil"
 	"mime"
 	"net/http"
 	"strings"
@@ -77,7 +76,7 @@ func (aH *APIHandler) saveSpans(w http.ResponseWriter, r *http.Request) {
 		bRead = gz
 	}
 
-	bodyBytes, err := ioutil.ReadAll(bRead)
+	bodyBytes, err := io.ReadAll(bRead)
 	if err != nil {
 		http.Error(w, fmt.Sprintf(handler.UnableToReadBodyErrFormat, err), http.StatusInternalServerError)
 		return
@@ -127,7 +126,7 @@ func (aH *APIHandler) saveSpansV2(w http.ResponseWriter, r *http.Request) {
 		bRead = gz
 	}
 
-	bodyBytes, err := ioutil.ReadAll(bRead)
+	bodyBytes, err := io.ReadAll(bRead)
 	if err != nil {
 		http.Error(w, fmt.Sprintf(handler.UnableToReadBodyErrFormat, err), http.StatusInternalServerError)
 		return

cmd/collector/app/zipkin/http_handler_test.go

@@ -20,7 +20,7 @@ import (
 	"compress/gzip"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"sync"
@@ -392,7 +392,7 @@ func postBytes(urlStr string, bytesBody []byte, header *http.Header) (int, strin
 	}
 	defer res.Body.Close()
 
-	body, err := ioutil.ReadAll(res.Body)
+	body, err := io.ReadAll(res.Body)
 	if err != nil {
 		return 0, "", err
 	}

cmd/collector/app/zipkin/jsonv2_test.go

@@ -16,7 +16,7 @@ package zipkin
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/go-openapi/swag"
@@ -147,7 +147,7 @@ func TestErrSpans(t *testing.T) {
 }
 
 func loadJSON(t *testing.T, fileName string, i interface{}) {
-	b, err := ioutil.ReadFile(fileName)
+	b, err := os.ReadFile(fileName)
 	require.NoError(t, err)
 	err = swag.ReadJSON(b, i)
 	require.NoError(t, err, "Failed to parse json fixture file %s", fileName)

cmd/collector/app/zipkin/protov2_test.go

@@ -17,7 +17,7 @@ package zipkin
 import (
 	"crypto/rand"
 	"encoding/json"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -67,7 +67,7 @@ func TestLCFromProtoSpanLocalEndpoint(t *testing.T) {
 }
 
 func loadProto(t *testing.T, fname string, spans *zipkinProto.ListOfSpans) {
-	b, err := ioutil.ReadFile(fname)
+	b, err := os.ReadFile(fname)
 	require.NoError(t, err)
 	err = json.Unmarshal(b, spans)
 	require.NoError(t, err)

cmd/docs/command_test.go

@@ -15,7 +15,7 @@
 package docs
 
 import (
-	"io/ioutil"
+	"os"
 	"strings"
 	"testing"
 
@@ -43,7 +43,7 @@ func TestOutputFormats(t *testing.T) {
 		cmd.ParseFlags([]string{test.flag})
 		err := cmd.Execute()
 		if err == nil {
-			f, err := ioutil.ReadFile(test.file)
+			f, err := os.ReadFile(test.file)
 			require.NoError(t, err)
 			assert.True(t, strings.Contains(string(f), "documentation"))
 		} else {
@@ -62,7 +62,7 @@ func TestDocsForParent(t *testing.T) {
 	parent.AddCommand(docs)
 	err := docs.RunE(docs, []string{})
 	require.NoError(t, err)
-	f, err := ioutil.ReadFile("root_command.md")
+	f, err := os.ReadFile("root_command.md")
 	require.NoError(t, err)
 	assert.True(t, strings.Contains(string(f), "some description"))
 }

cmd/query/app/http_handler_test.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"net/http"
 	"net/http/httptest"
@@ -239,7 +238,7 @@ func TestWriteJSON(t *testing.T) {
 	get := func(url string) string {
 		res, err := http.Get(url)
 		require.NoError(t, err)
-		body, err := ioutil.ReadAll(res.Body)
+		body, err := io.ReadAll(res.Body)
 		require.NoError(t, err)
 		return string(body)
 	}
@@ -843,15 +842,15 @@ func execJSON(req *http.Request, out interface{}) error {
 	defer resp.Body.Close()
 
 	if resp.StatusCode > 399 {
-		body, err := ioutil.ReadAll(resp.Body)
+		body, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return err
 		}
 		return fmt.Errorf("%d error from server: %s", resp.StatusCode, body)
 	}
 
 	if out == nil {
-		io.Copy(ioutil.Discard, resp.Body)
+		io.Copy(io.Discard, resp.Body)
 		return nil
 	}
 

cmd/query/app/static_handler.go

@@ -19,8 +19,9 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
+	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -212,7 +213,7 @@ func loadIndexHTML(open func(string) (http.File, error)) ([]byte, error) {
 		return nil, fmt.Errorf("cannot open index.html: %w", err)
 	}
 	defer indexFile.Close()
-	indexBytes, err := ioutil.ReadAll(indexFile)
+	indexBytes, err := io.ReadAll(indexFile)
 	if err != nil {
 		return nil, fmt.Errorf("cannot read from index.html: %w", err)
 	}
@@ -223,7 +224,7 @@ func loadUIConfig(uiConfig string) (*loadedConfig, error) {
 	if uiConfig == "" {
 		return nil, nil
 	}
-	bytesConfig, err := ioutil.ReadFile(filepath.Clean(uiConfig))
+	bytesConfig, err := os.ReadFile(filepath.Clean(uiConfig))
 	if err != nil {
 		return nil, fmt.Errorf("cannot read UI config file %v: %w", uiConfig, err)
 	}