'Docker Compose : NodeJS + MongoDB

I can't make my docker compose work.

Here's my dockerfile:

FROM node:0.12
RUN apt-get update -qq && apt-get install -y build-essential libpq-dev
RUN mkdir /myapp
WORKDIR /myapp
ADD . /myapp
RUN npm install

My docker-compose.yml

db:
  image: mongo
  ports:
    - 27017
web:
  build: .
  command: npm start
  volumes:
    - .:/myapp
  ports:
    - 3000:3000
  links:
    - db
  environment:
    PORT: 3000

And in server.js:

  var MONGO_DB;
  var DOCKER_DB = process.env.DB_1_PORT;
  if ( DOCKER_DB ) {
    MONGO_DB = DOCKER_DB.replace( "tcp", "mongodb" ) + "/dev_db";
  } else {
    MONGO_DB = process.env.MONGODB;
  }

  mongoose.connect(MONGO_DB);

as from duplicated from this repo: https://github.com/projectweekend/Node-Backend-Seed but process.env.DB_1_PORT is empty. How can I add it?

Thanks

node.jsmongodbdockerdocker-compose


Solution 1:[1]

Sorry @gettho.child, I accepted your answer too quickly. I thought it was working but it wasn't. I'll report here my final solution since I have been struggling quite some to achieve it.

Dockerfile:

FROM node:0.12
RUN apt-get update -qq && apt-get install -y build-essential libpq-dev libkrb5-dev
RUN mkdir /myapp
WORKDIR /myapp
ADD package.json /myapp/package.json
RUN npm install
ADD . /myapp

docker-compose.yml:

db:
  image: mongo
  ports:
    - "27017:27017"
  command: "--smallfiles --logpath=/dev/null"
web:
  build: .
  command: node app.js
  volumes:
    - .:/myapp
  ports:
    - "3000:3000"
  links:
    - db
  environment:
    PORT: 3000 # this is optional, allows express to use process.env.PORT instead of a raw 3000

And the interesting app.js extracts:

var MONGO_DB;
var DOCKER_DB = process.env.DB_PORT;
if ( DOCKER_DB ) {
  MONGO_DB = DOCKER_DB.replace( 'tcp', 'mongodb' ) + '/myapp';
} else {
  MONGO_DB = process.env.MONGODB;
}
var retry = 0;
mongoose.connect(MONGO_DB);

app.listen(process.env.PORT || 3000);

Regarding the process.env.DB_PORT I've tried many things around. If it doesn't work out-of-the-box, I suggest to console.log(process.env); and look for mongo's IP.

The final URL should look like: mongodb://172.17.0.76:27017/myapp

Good luck, it is worth it, Docker's awesome!

EDIT:

If the above works, I now found a techno-agnostic workflow by running:

  • docker-compose run web /bin/bash
  • and in there running printenv

I hope this is not too much self promotion but I wrote a double article on the topic which may help some of the readers: https://augustin-riedinger.fr/en/resources/using-docker-as-a-development-environment-part-1/

Cheers

Solution 2:[2]

Make sure that mongoDB IP (and port) in your 'Server.js' file is set to 'PORT_27017_TCP_ADDR' (check port too) - can be found when running 'docker exec {web app container id} env'.

Solution 3:[3]

Your docker-compose should be 

environment:
   - MONGODB=3000

See this link for more information on mapping environment variables. You are declaring the environment variable as PORT instead of MONGODB.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1
Solution 2 Asher A
Solution 3

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