config: add metrics_basic_auth option (#1917)

* config: add metrics_basic_auth option

* remove println

* use constant time compare

config/metrics_test.go

@@ -1,12 +1,14 @@
 package config
 
 import (
+	"encoding/base64"
 	"fmt"
 	"net"
 	"net/http"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestMetricsManager(t *testing.T) {
@@ -54,3 +56,32 @@ func TestMetricsManager(t *testing.T) {
 	assert.Equal(t, 500, getStatusCode(addr1))
 	assert.Equal(t, 200, getStatusCode(addr2))
 }
+
+func TestMetricsManagerBasicAuth(t *testing.T) {
+	li1, err := net.Listen("tcp", "127.0.0.1:0")
+	if !assert.NoError(t, err) {
+		return
+	}
+	addr1 := li1.Addr().String()
+	li1.Close()
+
+	src := NewStaticSource(&Config{
+		Options: &Options{
+			MetricsAddr:      addr1,
+			MetricsBasicAuth: base64.StdEncoding.EncodeToString([]byte("x:y")),
+		},
+	})
+	mgr := NewMetricsManager(src)
+	defer mgr.Close()
+
+	res, err := http.Get(fmt.Sprintf("http://%s/metrics", addr1))
+	assert.NoError(t, err)
+	assert.Equal(t, http.StatusUnauthorized, res.StatusCode)
+
+	req, err := http.NewRequest("GET", fmt.Sprintf("http://%s/metrics", addr1), nil)
+	require.NoError(t, err)
+	req.SetBasicAuth("x", "y")
+	res, err = http.DefaultClient.Do(req)
+	assert.NoError(t, err)
+	assert.Equal(t, http.StatusOK, res.StatusCode)
+}