Fix lint warnings

libbeat/licenser/elastic_fetcher.go

@@ -22,7 +22,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"math/rand"
 	"net/http"
 
 	"github.com/elastic/beats/v7/libbeat/esleg/eslegclient"
@@ -99,6 +98,7 @@ func (f *ElasticFetcher) parseJSON(b []byte) (License, error) {
 
 // esClientMux is taking care of round robin request over an array of elasticsearch client, note that
 // calling request is not threadsafe.
+// nolint: unused // it's used on Linux
 type esClientMux struct {
 	clients []eslegclient.Connection
 	idx     int
@@ -108,6 +108,7 @@ type esClientMux struct {
 // at the end of the function call, if an error occur we return the error and will pick up the next client on the
 // next call. Not that we just round robin between hosts, any backoff strategy should be handled by
 // the consumer of this type.
+// nolint: unused // it's used on Linux
 func (mux *esClientMux) Request(
 	method, path string,
 	pipeline string,
@@ -130,19 +131,3 @@ func (mux *esClientMux) Request(
 	}
 	return status, response, err
 }
-
-// newESClientMux takes a list of clients and randomize where we start and the list of  host we are
-// querying.
-func newESClientMux(clients []eslegclient.Connection) *esClientMux {
-	// randomize where we start
-	idx := rand.Intn(len(clients))
-
-	// randomize the list of round robin hosts.
-	tmp := make([]eslegclient.Connection, len(clients))
-	copy(tmp, clients)
-	rand.Shuffle(len(tmp), func(i, j int) {
-		tmp[i], tmp[j] = tmp[j], tmp[i]
-	})
-
-	return &esClientMux{idx: idx, clients: tmp}
-}

libbeat/licenser/elastic_fetcher_test.go

@@ -19,7 +19,6 @@ package licenser
 
 import (
 	"context"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -33,7 +32,7 @@ import (
 
 func newServerClientPair(t *testing.T, handler http.HandlerFunc) (*httptest.Server, *eslegclient.Connection) {
 	mux := http.NewServeMux()
-	mux.Handle("/_license/", http.HandlerFunc(handler))
+	mux.Handle("/_license/", handler)
 
 	server := httptest.NewServer(mux)
 
@@ -46,15 +45,17 @@ func newServerClientPair(t *testing.T, handler http.HandlerFunc) (*httptest.Serv
 
 	ctx, cancel := context.WithCancel(context.Background())
 	t.Cleanup(cancel)
-	client.Connect(ctx)
+	if err := client.Connect(ctx); err != nil {
+		t.Fatalf("cannot connect to ES: %s", err)
+	}
 
 	return server, client
 }
 
 func TestParseJSON(t *testing.T) {
 	t.Run("OSS release of Elasticsearch (Code: 405)", func(t *testing.T) {
 		h := func(w http.ResponseWriter, r *http.Request) {
-			http.Error(w, "Method Not Allowed", 405)
+			http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
 		}
 		s, c := newServerClientPair(t, h)
 		defer s.Close()
@@ -80,7 +81,7 @@ func TestParseJSON(t *testing.T) {
 
 	t.Run("malformed JSON", func(t *testing.T) {
 		h := func(w http.ResponseWriter, r *http.Request) {
-			w.Write([]byte("hello bad JSON"))
+			_, _ = w.Write([]byte("hello bad JSON"))
 		}
 		s, c := newServerClientPair(t, h)
 		defer s.Close()
@@ -93,7 +94,7 @@ func TestParseJSON(t *testing.T) {
 
 	t.Run("401 response", func(t *testing.T) {
 		h := func(w http.ResponseWriter, r *http.Request) {
-			http.Error(w, "Unauthorized", 401)
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
 		}
 		s, c := newServerClientPair(t, h)
 		defer s.Close()
@@ -118,14 +119,14 @@ func TestParseJSON(t *testing.T) {
 	})
 
 	t.Run("200 response", func(t *testing.T) {
-		filepath.Walk("testdata/", func(path string, i os.FileInfo, err error) error {
+		_ = filepath.Walk("testdata/", func(path string, i os.FileInfo, err error) error {
 			if i.IsDir() {
 				return nil
 			}
 
 			t.Run(path, func(t *testing.T) {
 				h := func(w http.ResponseWriter, r *http.Request) {
-					json, err := ioutil.ReadFile(path)
+					json, err := os.ReadFile(path)
 					if err != nil {
 						t.Fatal("could not read JSON")
 					}