Run 2 different containers from same node project

Question

I have a node project that has a web server and a service on the root.

--myNodeProj
  --app.js //the web server
  --service.js //an update service

In my package.json I have the following:

"scripts": {
    "start": "node app.js",
    "service": "node service.js"
  },

For my DockerFile I have:

FROM node:8

# Create app directory
WORKDIR /usr/src/app

# Install app dependencies
# A wildcard is used to ensure both package.json AND package-lock.json are copied
# where available (npm@5+)
COPY package*.json ./

RUN npm install
# If you are building your code for production
# RUN npm install --only=production

# Bundle app source
COPY . .

EXPOSE 8080
CMD [ "npm", "start" ]

The CMD will run the app.js (webserver). How do I build another container with the service? Do I create another Dockerfile? Would the docker build command look different?

Answer 1

You can override the command - docker run <image> node service.js

https://docs.docker.com/engine/reference/run/#general-form

Answer 2

I ended up using docker-compose. You need to create a docker-compose.yml file with the following code:

version: '3'
services:
  web:
    # will build ./docker/web/Dockerfile
    build:
      context: .
      dockerfile: ./docker/web/Dockerfile
    ports:
      - "3000:3000"
    env_file:
      - web.env
  service:
    # will build ./docker/service/Dockerfile
    build:
      context: .
      dockerfile: ./docker/service/Dockerfile
    env_file:
      - service.env

This files reference 2 Dockerfiles that build the containers:

For service

FROM node:8

# Create app directory
WORKDIR /usr/src/service

# Install app dependencies
# A wildcard is used to ensure both package.json AND package-lock.json are copied
# where available (npm@5+)
COPY package*.json ./

RUN npm install
# If you are building your code for production
# RUN npm install --only=production

# Bundle app source
COPY . .

CMD [ "node", "service.js" ]

For web:

FROM node:8

# Create app directory
WORKDIR /usr/src/app

# Install app dependencies
# A wildcard is used to ensure both package.json AND package-lock.json are copied
# where available (npm@5+)
COPY package*.json ./

RUN npm install
# If you are building your code for production
# RUN npm install --only=production

# Bundle app source
COPY . .

#EXPOSE 8080
CMD [ "npm", "start" ]

Notice that I can only do one NPM start. I call the service directly using node.

When I want to build containers, I issue the command:

docker-compose build