Why can't I do knex migrate:latest using Docker-Composer?

I have the following docker-compose.yml where I’m starting two services:

• postgres
• nodejs app

After the Postgres DB is up I try to run knex migrate:latest to create the DB structure. But for some reason the migration keep telling me that is unable to connect. This is strange because:

• I’m able to connect to the DB using Postico and work with the DB no problem.
• The nodejs app is able to connect because I get an error message telling me that the table that I’m trying to select from dose not exists.
• I’m able to ping the DB container from the Web container

Question

What am I missing?

File: docker-compose.yml

version: '2'

services:

  postgres:
    image: "postgres"
    ports:
     - "5433:5432"
    networks:
     - curted
    environment:
     POSTGRES_DB: dbname
     POSTGRES_USER: admin
     POSTGRES_PASSWORD: admin
    volumes:
     - database:/var/lib/postgresql/data

  example.com:
    build: .
    ports:
     - "5000:5000"
    volumes:
     - .:/code
    networks:
     - example
    working_dir: /code
    environment:
     DATABASE_URL: postgres://admin:admin@172.18.0.2:5433/dbname
     NODE_ENV: local
    command: bash -c "sleep 10 && npm run knex migrate:latest --file knexfile.js"
    depends_on:
     - postgres

networks:
  curted:
    driver: bridge

volumes:
  database:

The knexfile.js

module.exports = {
	local: {
		client: 'pg',
		connection: process.env.DATABASE_URL,
		ssl: false,
		migrations: {
			tableName: 'knex_migrations'
		}
	},
	staging: {
		client: 'pg',
		connection: process.env.DATABASE_URL,
		ssl: true,
		migrations: {
			tableName: 'knex_migrations'
		},
		pool: {
			min: 1,
			max: 2
		}
	},
	production: {
		client: 'pg',
		connection: process.env.DATABASE_URL,
		ssl: true,
		migrations: {
			tableName: 'knex_migrations'
		},
		pool: {
			min: 1,
			max: 2
		}
	}
};

Erro Message

curted.com_1  | > CuratedProducts@1.0.0 knex /home/app
curted.com_1  | > knex "migrate:latest"
curted.com_1  |
curted.com_1  | Using environment: local
curted.com_1  | Error: connect ECONNREFUSED 172.18.0.2:5433
curted.com_1  |     at Object.exports._errnoException (util.js:1022:11)
curted.com_1  |     at exports._exceptionWithHostPort (util.js:1045:20)
curted.com_1  |     at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1090:14)

[vulgur]

Hey guys, I found the reason and the solution. The solution is generally speaking the same as @Bram-Zijp . Here is my knexfile.js:

module.exports = {

  development: {
    client: 'mysql2',
      debug:true,
    connection: {
        host:'docker-mysql',
        user: 'root',
        password: '1qaz',
        port: '',
        database: 'docker_db'
    },
      migrations: {
          tableName: 'knex_migrations'
      }
  },
};

The key is to set host with the name of the db service in docker-compose. Setting port to empty string or 3306 both will okay ( I don’t know why but it works).

The ECONNREFUSED error means the web app cannot connect the db, and I’ve tried many hosts and ports but all the tries failed, like localhost:3306 and 0.0.0.0:13306 and so on. The reason is the localhost:3306 actually refers the container itself, not the docker host.

Plus, make sure the migration is executed after db fully initializing.

References：

1. https://medium.com/@niratattri/building-a-node-js-application-and-deploying-through-docker-meet-docker-aa8ae677ea12
2. https://stackoverflow.com/questions/45399941/node-js-connect-to-mysql-docker-container-econnrefused

[davidgatti]

OK. I’ll dig deeper, and will let you know.