router.Run() can be called without parameters. #405

utils.go

@@ -7,6 +7,7 @@ package gin
 import (
 	"encoding/xml"
 	"net/http"
+	"os"
 	"path"
 	"reflect"
 	"runtime"
@@ -129,3 +130,20 @@ func joinPaths(absolutePath, relativePath string) string {
 	}
 	return finalPath
 }
+
+func resolveAddress(addr []string) string {
+	switch len(addr) {
+	case 0:
+		if port := os.Getenv("PORT"); len(port) > 0 {
+			debugPrint("Environment variable PORT=\"%s\"", port)
+			return ":" + port
+		} else {
+			debugPrint("Environment variable PORT is undefined. Using port :8080 by default")
+			return ":8080"
+		}
+	case 1:
+		return addr[0]
+	default:
+		panic("too much parameters")
+	}
+}