Discussion on: Dockerize a Node.js app with VS Code

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Replies for: For the PHPMyAdmin bit, are you exposing a port on the DB image? If you put two images on a Docker network like that, they just talk to everything ...

For the Node -> DB bit, do you mind sharing your docker-compose.yaml and the connection string you're using in your Node container?

Bassem • Jun 24 '19

Yeah sure, No problem!

version: "2"

networks:
  app-tier:
    driver: bridge

services:
  # Mysql database
  frostdb:
    image: frost/db
    hostname: frostdb

    networks:
      - app-tier
    ports:
      - "3306:3306"

  # NodeJS backend server
  frostback:
    image: frost/back
    hostname: frostback

    networks:
      - app-tier
    links:
      - frostdb:frostdb
    depends_on:
      - frostdb
    ports:
      - "49160:8080"

  # Frontend server
  frostgui:
    image: frost/gui
    hostname: frostgui

    links:
      - frostback:frostback
    ports:
      - "49170:3000"

I think that I am exposing ports using the "3306:3306". and for the backend config, I have a .env file

NODE_ENV=development

DB_TYPE=mysql
DB_NAME=frost
DB_HOST=localhost
DB_USER=USER
DB_PASSWORD=PASS
DB_PORT=3306

Actually, I have no idea what the username/password for the DB should be. But that's not the issue anyway according to the logs.

Henry Quinn • Jun 24 '19

You're correct that you're exposing port 3306.

Your ENV file looks good, but what about the line of code that's using those ENV variables?

Comment deleted

Bassem • Jun 25 '19

I am using a package called Sequelize for connecting to the DB and here is how :

const url = `${process.env.DB_TYPE}://${process.env.DB_USER}:${
      process.env.DB_PASSWORD
    }@${process.env.DB_HOST}:${process.env.DB_PORT}/${process.env.DB_NAME}`;
    this.db = new Sequelize(url, {
      define: {
        charset: "utf8mb4",
        collate: "utf8mb4_general_ci",
        timestamps: true
      }
    });

Running docker-compose up produces this error :

Unhandled rejection SequelizeConnectionRefusedError: connect ECONNREFUSED 127.0.0.1:3306

Could it be that the DB is not yet up and running?

Henry Quinn • Jun 25 '19 • Edited

I mean, could be. Have you tried using Kitematic or docker exec -it <container name> /bin/bash?

Also, what is your output for docker ps -a when you have your compose file spun up?

Edit: I see a couple things that could be at fault here, but I want to see the answer to those two questions before I take a stab at it. ^{^}

Henry Quinn • Jun 26 '19

I'd consider updating your docker-compose.yaml to version 3.x and use the container_name item to force a name on your container.

Then, in your ENV file, use whatever you set that container_name to DB_HOST. I understand why you're trying to use localhost, but if all of these containers are on one Docker network, they'll want to refer to each other by their container names.

Bassem • Jun 26 '19

I feel like i need to have a better understanding of docker.

Definitely will try doing that and will update you.

Henry Quinn • Jun 26 '19

We all start somewhere, my dude. :)