使用Docker连接Node.js与MongoDB时出现连接错误求助

错误信息 #

techworld-js-docker-demo-app-mongo-express-1  | 无法使用连接字符串连接到数据库: mongodb://admin:password@mongodb:27017/"
techworld-js-docker-demo-app-mongo-express-1  | (node:7) UnhandledPromiseRejectionWarning: MongoNetworkError: 首次连接时无法连接到服务器 [mongodb:27017] [Error: connect ECONNREFUSED 172.19.0.3:27017
techworld-js-docker-demo-app-mongo-express-1  |     at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1144:16) {
techworld-js-docker-demo-app-mongo-express-1  |   name: 'MongoNetworkError'
techworld-js-docker-demo-app-mongo-express-1  | }]
techworld-js-docker-demo-app-mongo-express-1  |     at Pool.<anonymous> (/node_modules/mongodb/lib/core/topologies/server.js:441:11)
techworld-js-docker-demo-app-mongo-express-1  |     at Pool.emit (events.js:314:20)
techworld-js-docker-demo-app-mongo-express-1  |     at /node_modules/mongodb/lib/core/connection/pool.js:564:14
techworld-js-docker-demo-app-mongo-express-1  |     at /node_modules/mongodb/lib/core/connection/pool.js:1000:11
techworld-js-docker-demo-app-mongo-express-1  |     at /node_modules/mongodb/lib/core/connection/connect.js:32:7
techworld-js-docker-demo-app-mongo-express-1  |     at callback (/node_modules/mongodb/lib/core/connection/connect.js:300:5)
techworld-js-docker-demo-app-mongo-express-1  |     at Socket.<anonymous> (/node_modules/mongodb/lib/core/connection/connect.js:330:7)
techworld-js-docker-demo-app-mongo-express-1  |     at Object.onceWrapper (events.js:421:26)
techworld-js-docker-demo-app-mongo-express-1  |     at Socket.emit (events.js:314:20)
techworld-js-docker-demo-app-mongo-express-1  |     at emitErrorNT (internal/streams/destroy.js:92:8)
techworld-js-docker-demo-app-mongo-express-1  |     at emitErrorAndCloseNT (internal/streams/destroy.js:60:3)
techworld-js-docker-demo-app-mongo-express-1  |     at processTicksAndRejections (internal/process/task_queues.js:84:21)
techworld-js-docker-demo-app-mongo-express-1  | (node:7) UnhandledPromiseRejectionWarning: 未处理的Promise拒绝。此错误要么是因为在没有catch块的async函数中抛出，要么是因为拒绝了一个未用.catch()处理的Promise。要在未处理的Promise拒绝时终止Node进程，请使用CLI标志`--unhandled-rejections=strict`。(拒绝id: 1)

当前配置 #

docker-compose.yaml #

version: '3'
services:
  my-app:
    image: nihalchandra/myapp:4.0
    ports:
      - 3000:3000
  mongodb:
    image: mongo
    restart: always
    ports:
      - 27017:27017
    environment:
      - MONGO_INITDB_ROOT_USERNAME=admin
      - MONGO_INITDB_ROOT_PASSWORD=password
    volumes:
      - mongo-data:/data/db
  mongo-express:
    image: mongo-express
    restart: always # 修复mongo-express启动时mongodb未就绪导致的MongoNetworkError
    ports:
      - 8081:8081
    environment:
      - ME_CONFIG_MONGODB_ADMINUSERNAME=admin
      - ME_CONFIG_MONGODB_ADMINPASSWORD=password
      - ME_CONFIG_MONGODB_SERVER=mongodb
volumes:
  mongo-data:
   driver: local

server.js中的连接配置 #

let mongoUrlLocal = "mongodb://admin:password@localhost:27017";
let mongoUrlDocker = "mongodb://admin:password@mongodb";

解决方案 #

• 修正连接字符串，指定认证库：
  root用户的认证需要指定authSource=admin，Docker环境的连接字符串应改为：

  let mongoUrlDocker = "mongodb://admin:password@mongodb:27017/?authSource=admin";
  

• 确保my-app使用Docker环境的连接地址：
  在docker-compose.yaml的my-app服务中添加环境变量，明确告知应用使用Docker配置：

  my-app:
    image: nihalchandra/myapp:4.0
    ports:
      - 3000:3000
    environment:
      - NODE_ENV=docker
  

  然后在server.js中根据环境变量自动选择连接地址：

  const mongoUrl = process.env.NODE_ENV === 'docker' 
    ? "mongodb://admin:password@mongodb:27017/?authSource=admin" 
    : "mongodb://admin:password@localhost:27017/?authSource=admin";
  

• 添加服务依赖与重启策略：
  让my-app在mongodb启动后再启动，并添加重启策略，避免因MongoDB未就绪导致的连接失败：

  my-app:
    image: nihalchandra/myapp:4.0
    ports:
      - 3000:3000
    environment:
      - NODE_ENV=docker
    restart: always
    depends_on:
      - mongodb
  

  注意：depends_on仅保证启动顺序，不保证MongoDB完全就绪，建议在应用的数据库连接逻辑中添加重试机制，比如使用MongoDB驱动的重试参数或自定义重试逻辑。

• 检查网络连通性：
  进入my-app容器，测试与mongodb服务的连通性：

  docker exec -it techworld-js-docker-demo-app-my-app-1 ping mongodb
  

  如果ping不通，检查是否所有服务都在同一个Docker网络中（默认docker-compose会创建默认网络，所有服务自动加入）。

内容的提问来源于stack exchange，提问作者Nihal_20