Docker-compose mongoose

Question

I'm new to Docker, and I'm trying the simplest of setups with docker-compose, but don't succeed to connect to Mongodb.

My docker-compose.local.yaml file:

version: "2"
services:
  posts-api:
    build:
      dockerfile: Dockerfile.local
      context: ./
    volumes:
      - ".:/app"
    ports:
      - "6820:6820"
    depends_on:
      - mongodb
  mongodb:
    image: mongo:3.5
    ports:
      - "27018:27018"
    command: mongod --port 27018

My Docker file:

FROM node:7.8.0
MAINTAINER Livefeed '[email protected]'

RUN mkdir /app
VOLUME /app
WORKDIR /app

ADD package.json yarn.lock ./
RUN eval rm -rf node_modules && \
yarn

ADD server.js .
RUN mkdir config src
ADD config config/
ADD src src/

EXPOSE 6820
EXPOSE 27018

CMD yarn run local

In server.js I try to connect with:

mongoose.connect('mongodb://localhost:27018');

I also tried:

mongoose.connect('mongodb://mongodb:27018');

To run docker-compose:

docker-compose -f docker-compose.local.yaml up --build 

And I receive the error:

connection error: { MongoError: failed to connect to server [localhost:27018] on first connect [MongoError: connect ECONNREFUSED 127.0.0.1:27018]

What am I missing?

Answer 1

In server.js use mongodb instead of localhost:

mongoose.connect('mongodb://mongodb:27018');

Because containers in the same network can communicate using their service name.

Bear in mind that each container and your host have their own localhost. Each localhost is a different host: container A, container B, your host (each one has its own network interface).

---

Edit:

Be sure to get your mongo up:

docker-compose logs mongodb
docker-compose ps

Sometimes it doesn't get up because of disk space.

---

Edit 2:

With newer versions of mongo, you need to specify to listen to all interfaces too:

command: mongod --port 27018 --bind_ip_all

Answer 2

I think, that you should add links option in your config. Like this:

ports:
  - "6820:6820"
depends_on:
  - mongodb
links:
  - mongodb

update

As I promised

version: '2.1'
services:
    pm2:
      image: keymetrics/pm2-docker-alpine:6
      restart: always
      container_name: pm2
      volumes:
        - ./pm2:/app
      links:
        - redis_db
        - db
      environment:
        REDIS_CONNECTION_STRING: redis://redis_db:6379

    nginx:
      image: firesh/nginx-lua
      restart: always
      volumes:
        - ./nginx:/etc/nginx
        - /var/run/docker.sock:/tmp/docker.sock:ro
      ports:
        - 80:80
      links:
        - pm2

        s3: # mock for development
      image: lphoward/fake-s3:latest

    redis_db:
      container_name: redis_db
      image: redis
      ports:
        - 6379:6379

    db: # for scorebig-syncer
      image: mysql:5.7
      ports:
        - 3306:3306