Flutter聊天应用连接Docker部署的RethinkDB时出现连接拒绝错误

问题详情 #

将Flutter聊天应用连接Docker部署的RethinkDB服务器时，抛出异常：

Unhandled Exception: Could not connect to 127.0.0.1:28015. Error SocketException: Connection refused (OS Error: Connection refused, errno = 111)

已确认RethinkDB容器处于运行状态，将连接地址从127.0.0.1更换为本机IP后问题仍未解决。

相关代码 #

CompositionRoot.dart #

import 'package:chat/chat.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_newapp/src/blocs/onBoarding/onboarding_cubit.dart';
import 'package:flutter_newapp/src/blocs/onBoarding/prfil_image_cubit.dart';
import 'package:flutter_newapp/src/data/Services/image_uploader.dart';
import 'package:flutter_newapp/src/data/Services/local_cache.dart';
import 'package:flutter_newapp/src/presentation/screen/onBoarding/onboarding.dart';
import 'package:rethink_db_ns/rethink_db_ns.dart';
import 'package:shared_preferences/shared_preferences.dart';

class CompositionRoot {
  static late SharedPreferences _sharedPreferences;
  static late RethinkDb _r;
  static late Connection _connection;
  static late IUserService _userService;
  static late ILocalCache _localCache;
  static late ImageUploader imageUploader;

  static configure() async {
    _r = RethinkDb();
    _connection = await _r.connect(host: "127.0.0.1", port: 28015);
    _userService = UserService(_r, _connection);
    _localCache = LocalCache(_sharedPreferences);
  }

  static Widget composeOnboardingUi() {

    ImageUploader imageUploader = ImageUploader('http://localhost:3000/upload');
    OnBoardingCubit onboardingCubit =
        OnBoardingCubit(_userService, _localCache, imageUploader);

    return MultiBlocProvider(providers:[
      BlocProvider(create: (BuildContext context) => onboardingCubit ),
      BlocProvider(create: (BuildContext context) => ProfileImageCubit() )
    ], child: OnBoardingScreen());
  }
}

main.dart #

import 'package:flutter/material.dart';
import 'package:flutter_newapp/core/app_theme.dart';
import 'package:flutter_newapp/src/presentation/screen/onBoarding/onboarding.dart';

import 'composition_root.dart';

void main() async {
 WidgetsFlutterBinding.ensureInitialized();
 await CompositionRoot.configure();
 runApp(const MyApp());
}

class MyApp extends StatelessWidget {
 const MyApp({super.key});

 // This widget is the root of your application.
 @override
 Widget build(BuildContext context) {
   return MaterialApp(
     title: 'Chat App',
     debugShowCheckedModeBanner: false,
     theme: lightTheme(context),
     darkTheme: darkTheme(context),
     home: CompositionRoot.composeOnboardingUi(),
   );
 }
}

解决方案 #

1. 验证Docker端口映射 #

运行docker ps检查RethinkDB容器的端口映射，确认存在0.0.0.0:28015->28015/tcp的映射。如果没有，重新启动容器时添加端口映射参数：

docker run -p 28015:28015 rethinkdb

2. 修改RethinkDB绑定地址 #

默认RethinkDB仅绑定容器内的127.0.0.1，外部无法访问。启动容器时指定绑定所有地址：

docker run -p 28015:28015 rethinkdb rethinkdb --bind all

3. 调整Flutter连接地址 #

• 真机测试：使用主机的局域网IP（如192.168.x.x），确保手机和主机在同一局域网。
• Android模拟器：用10.0.2.2映射主机的127.0.0.1。
• iOS模拟器：可直接使用localhost或主机IP。

修改CompositionRoot.dart中的连接代码：

_connection = await _r.connect(host: "你的目标地址", port: 28015);

4. 排查防火墙限制 #

确认主机防火墙未拦截28015端口：

• Linux：执行sudo ufw allow 28015
• Windows：在防火墙高级设置中添加入站规则允许28015端口

内容的提问来源于stack exchange，提问作者FERHATI KHALIL