Docker Compose部署NestJS+MongoDB遇ECONNREFUSED错误求助

问题现象 #

在Windows 11主机上使用Docker Compose搭建NestJS + TypeORM + MongoDB环境时，出现数据库连接被拒绝的错误，错误日志如下：

nestjs-docker-api-1    | [Nest] 1  - 07/23/2022, 8:45:32 AM   ERROR [TypeOrmModule] Unable to connect to the database. Retrying (1)...
nestjs-docker-api-1    | MongoServerSelectionError: connect ECONNREFUSED 127.0.0.1:27018
nestjs-docker-api-1    |     at Timeout._onTimeout (/usr/src/app/node_modules/mongodb/lib/sdam/topology.js:293:38)
nestjs-docker-api-1    |     at listOnTimeout (internal/timers.js:554:17)
nestjs-docker-api-1    |     at processTimers (internal/timers.js:497:7)

现有配置 #

Dockerfile #

FROM node:12

# Create app directory
WORKDIR /usr/src/app

# A wildcard is used to ensure both package.json AND package-lock.json are copied
COPY package*.json ./

# Install app dependencies
RUN npm install 

# Bundle app source
COPY . .


EXPOSE 8080

# Creates a "dist" folder with the production build
RUN npm run build

# Start the server using the production build
CMD [ "node", "dist/main.js" ]

docker-compose.yml #

version: "3.9"
services:
    mongo:
        image: mongo
        ports:
            - "27018:27017"
        restart: always
        environment: 
              ME_CONFIG_MONGODB_ADMINUSERNAME: root
              ME_CONFIG_MONGODB_ADMINPASSWORD: example 
    api:
        image: image_name
        build: . 
        depends_on: 
            - mongo
        environment: 
            NODE_ENV: development
            PORT: 3000
            USERNAME : root,
            PASSWORD : example
        ports:
            - "8000:3000"

TypeORM配置 #

@Module({
  imports: [ TypeOrmModule.forRoot({
    type: 'mongodb',
    host: 'localhost',
    port: 27018,
    database: 'admin',
    entities: [],
    synchronize: true,
  })],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

解决方案 #

1. 修正MongoDB连接地址与端口 #

Docker容器内的localhost指向容器自身，而非主机。Docker Compose中，服务名可作为域名直接访问，因此：

• 将TypeORM配置中的host改为mongo（对应docker-compose中的服务名）
• 端口改为Mongo容器内部的27017（主机映射的27018仅用于主机访问容器，容器间通信使用内部端口）

2. 补充MongoDB认证配置 #

docker-compose中设置了管理员账号，但TypeORM配置未包含认证信息，需添加：

• username和password（建议通过环境变量获取，避免硬编码）
• 指定authSource: 'admin'（root用户属于admin数据库）

3. 修复MongoDB初始化环境变量 #

ME_CONFIG_*是mongo-express的配置变量，MongoDB官方镜像初始化root用户需使用MONGO_INITDB_ROOT_USERNAME和MONGO_INITDB_ROOT_PASSWORD，否则不会创建指定的管理员账号。

4. 解决容器启动顺序问题 #

depends_on仅保证容器启动顺序，不保证服务就绪。通过healthcheck配合depends_on的condition，确保NestJS容器在Mongo服务可用后再启动。

5. 修正docker-compose环境变量语法 #

api服务的USERNAME和PASSWORD后多了逗号，需删除，否则环境变量会包含无效字符。

修改后的配置 #

修改后的TypeORM配置 #

@Module({
  imports: [ TypeOrmModule.forRoot({
    type: 'mongodb',
    host: 'mongo',
    port: 27017,
    database: 'admin',
    username: process.env.USERNAME,
    password: process.env.PASSWORD,
    authSource: 'admin',
    entities: [],
    synchronize: true,
  })],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

修改后的docker-compose.yml #

version: "3.9"
services:
    mongo:
        image: mongo
        ports:
            - "27018:27017"
        restart: always
        environment: 
              MONGO_INITDB_ROOT_USERNAME: root
              MONGO_INITDB_ROOT_PASSWORD: example 
        healthcheck:
            test: ["CMD", "mongosh", "--eval", "db.adminCommand('ping')"]
            interval: 5s
            timeout: 5s
            retries: 5
    api:
        image: image_name
        build: . 
        depends_on: 
            mongo:
                condition: service_healthy
        environment: 
            NODE_ENV: development
            PORT: 3000
            USERNAME: root
            PASSWORD: example
        ports:
            - "8000:3000"

内容的提问来源于stack exchange，提问作者Thịnh Cường