Dockerfile

ARG PORT=3000
FROM node:16-alpine AS node

# Builder stage
FROM node AS builder
# Use /app as the CWD
WORKDIR /app            
# Copy package.json and package-lock.json to /app
COPY package*.json ./   
# Install all dependencies
RUN npm i               
# Copy the rest of the code
COPY . .                
# Invoke the build script to transpile code to js
RUN npm run build    
# Open desired port
EXPOSE ${PORT}   
# Run development server
ENTRYPOINT [ "npm", "run", "dev:no-reload" ]

# Final stage
FROM node AS final
# Set node environment to production
ENV NODE_ENV production
# Update the system
RUN apk --no-cache -U upgrade
# Prepare destination directory and ensure user node owns it
RUN mkdir -p /home/node/app/dist && chown -R node:node /home/node/app
# Set CWD
WORKDIR /home/node/app
# Install PM2
RUN npm i -g pm2
# Copy package.json, package-lock.json and process.yml
COPY package*.json process.yml ./
# Install libraries
RUN npm i --omit=dev
# Switch to user node
USER node
# Copy js files and change ownership to user node
COPY --chown=node:node --from=builder /app/dist ./dist
# Open desired port
EXPOSE ${PORT}
# Use PM2 to run the application as stated in config file
ENTRYPOINT ["pm2-runtime", "./process.yml"]