Docker Compose 连接 ECONNREFUSED 172.18.0.4:3306

Question

When I build the container of the project with this command:

sudo docker build -t PROJECT_NAME .

And then I download the mysql's image through this Docker-Compose config:

  db:
    image: mysql
    restart: always
    ports:
      - "8999:3306"
    networks:
      - webnet
    environment:
      MYSQL_DATABASE: slack
      MYSQL_ROOT_PASSWORD: admin

And then, the project will connect with MySQL through the Sequelize ORM

I have this error:

Unhandled rejection SequelizeConnectionRefusedError: connect ECONNREFUSED 172.18.0.4:3306

How can I resolve this?

The Sequelize config is this:

const sequelize = new Sequelize(process.env.TEST_DB || 'slack', 'root', 'admin', {
  host: process.env.DB_HOST || 'localhost',
  operatorsAliases: Sequelize.Op,
  dialect: 'mysql',
  define: {
    underscored: true
  }
});

The config of the web is this:

web:
    image: slack-clone-server
    ports:
      - "8080:8080"
    networks:
      - webnet
    environment:
      DB_HOST: db
      REDIS_HOST: redis
    command: ["./wait-for-it.sh", "db:3306", "--", "npm", "run", "prod"]

The script called "wait for it" is this .

If someone needs the complete code, here you go:

Sequelize config

Docker Compose config

Dockerfile config

Answer 1

wait-for-it.sh by default waits for 15 seconds and returns, even if the target isn't ready yet. You see that in your output too. But the database isn't ready yet. Make wait-for-it.sh wait longer , maybe with -t 90 to wait for 90 seconds or -t 0 to make it wait forever.

(In my experience the Docker database containers routinely take 30-60 seconds to start up, especially the first time.)

Answer 2

David already said that the db is not ready at this moment. You can use depends_on in your docker-compose file as well. This will start and initialize the db first and then start the "web" container.

services:
  web:
    ...
    depends_on:
      - db

  db:
    image: mariadb:latest
    ...

Answer 3

db:
    container_name: mysqldb //or whatever you want <<Add This
    image: mysql
    restart: always
    ports:
      - "8999:3306"
    networks:
      - webnet
    environment:
      MYSQL_DATABASE: slack
      MYSQL_ROOT_PASSWORD: admin

And Then assign the value of process.env.DB_HOST to Mysql Container name

Like: process.env.DB_HOST=mysqldb

Answer 4

Assign the value of process.env.DB_HOST to Mysql Container name

Like: process.env.DB_HOST=mysqldb