Run 2 different containers from same node project - node.js

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