- you should use the 'node' official image, with the alpine 6.x branch
- this app listens on port 3000, but the container should launch on port 80 so it will respond to http://localhost:80 on your computer
- then it should use alpine package manager to install tini
- then it should create directory /usr/src/app for app files
- Node uses a "package manager", so it needs to copy in package.json file
- then it needs to run 'npm install' to install dependencies from that file
- to keep it clean and small, run 'npm cache clean --force' after above
- then it needs to copy in all files from current directory
- then it needs to start container with command '/sbin/tini -- node ./bin/www'