support host/domain name in the original url

allocate_test.go

@@ -5,8 +5,10 @@ import (
 	"context"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"os"
 	"os/exec"
 	"strings"
@@ -142,6 +144,26 @@ func TestRemoteAllocator(t *testing.T) {
 				return "http" + wsURL[2:strings.Index(wsURL, "devtools")]
 			},
 		},
+		{
+			name: "hostname",
+			modifyURL: func(wsURL string) string {
+				h, err := os.Hostname()
+				if err != nil {
+					t.Fatal(err)
+				}
+				u, err := url.Parse(wsURL)
+				if err != nil {
+					t.Fatal(err)
+				}
+				_, post, err := net.SplitHostPort(u.Host)
+				if err != nil {
+					t.Fatal(err)
+				}
+				u.Host = net.JoinHostPort(h, post)
+				u.Path = "/"
+				return u.String()
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

util.go

@@ -55,7 +55,7 @@ func detectURL(urlstr string) string {
 	u.Path = "/json/version"
 
 	// to get "webSocketDebuggerUrl" in the response
-	resp, err := http.Get(u.String())
+	resp, err := http.Get(forceIP(u.String()))
 	if err != nil {
 		return urlstr
 	}