node.js - 无法从Docker容器连接到Redis

Question

/下面的摘录来自docker-compose.yml文件/

version: "3"
services:
  app:
    container_name: app
    restart: always
    build: .
    ports:
      - "3006:3006"
    # deploy:
    #   mode: replicated
      #replicas: 6
    networks: 
      - overlay
    depends_on:
      - redis
      - mongo
      - mysql
    links:
      - mongo
      - redis
      - mysql
  mongo:
    container_name: mongo
    networks: 
      - overlay
    image: mongo
    volumes:
      - ./data:/data/db
    ports:
      - "27017:27017"
  redis:
    image: redis:latest
    networks: 
      - overlay
    volumes:
      - ./data:/redisdata/redisdb
    ports:
      - "6379:6379"
    logging:
      driver: "json-file"
      options:
        max-size: "100MB"
        max-file: "3"
  mysql:
    image: mysql:latest
    networks: 
     - overlay
    ports: 
    - "3307:3307"
    environment:
      - 'MYSQL_ROOT_PASSWORD=******'
      - 'MYSQL_DATABASE=iconnect_test_demo'
      - 'MYSQL_USER=root'
      - 'MYSQL_PASSWORD=******'
networks:
 overlay:

在执行上面的docker-compose.yml文件后，所有4个容器都已创建，但无法连接到Redis数据库并收到以下异常。尝试用localhost替换Redis，但仍然没有运气。但是如果我在Docker外部独立运行节点程序，它将获得连接重新依赖容器内部的数据库。

在执行过程中导致以下错误。

[ioredis] Unhandled error event: Error: connect ECONNREFUSED 127.0.0.1:6379
app      |     at Object.exports._errnoException (util.js:1050:11)
app      |     at exports._exceptionWithHostPort (util.js:1073:20)
app      |     at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1093:14)

Complete Error Log is pasted in below url.
https://pastebin.com/0NvC3nz6

In Node File trying to connect to redis server in the following way.

var Redis = require('ioredis'); 
var redisadapter = require('socket.io-redis');


/* For maintaining connectivity across the multiple nodes */
io.adapter(redisadapter({ host: 'redis', port: 6379 }));
#io.adapter(redisadapter({ host: 'localhost', port: 6379 }));
server.listen(3006);
console.log("server running on 3006");

/* Redis configuration */
var redis_address = 'redis://redis:6379';
#var redis_address = 'redis://localhost:6379';
var redis = new Redis(redis_address);

redis.on('ECONNREFUSED', function(err) {    
  logger.error('Redis error: ' + err);
} );

/ Docker文件/

FROM node:7
WORKDIR /app
COPY . /app
CMD node server1.js
EXPOSE 3006

Answer 1

如果您在日志文件中查看此特定行:

app      | [ioredis] Unhandled error event: Error: connect ECONNREFUSED 127.0.0.1:6379

它告诉您应用程序容器无法连接到Redis容器。 Redis实例的IP地址在端口6379上为 127.0.0.1 。但是，在这里，您的redis服务器不在app容器上运行，而是在redis容器上运行。您的代码或配置中有问题。有关更多详细信息，请查看所用库的文档。此外，确保每次更改代码中的内容时都重新构建应用docker镜像!