Dockerfile

# The first thing we need to do is define from what image we want to build from.
# Here we will use the latest LTS (long term support) version 10 of node available from the Docker Hub (https://hub.docker.com/_/node/)
FROM node:10

# Next we create a directory to hold the application code inside the image, this will be the working directory for your application
WORKDIR /usr/src/app

# This image comes with Node.js and NPM already installed so the next thing we need to do is to install your app dependencies using the npm binary.
# 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 ./

# Note that, rather than copying the entire working directory, we are only copying the package.json file.
# This allows us to take advantage of cached Docker layers. bitJudo has a good explanation of this here (http://bitjudo.com/blog/2014/03/13/building-efficient-dockerfiles-node-dot-js/).

# If you are building your code for production
RUN npm install --production
RUN npm install -g pm2
RUN npm link pm2

# To bundle your app's source code inside the Docker image, use the COPY instruction
# Bundle app source
COPY . .

# Your app binds to port 3000 so you'll use the EXPOSE instruction to have it mapped by the docker daemon
EXPOSE 3000

# Last but not least, define the command to run your app using CMD which defines your runtime.
# Here we will use the basic npm start which will run node server.js to start your server
CMD [ "npm", "start" ]