Node.js real-time multi-player quiz

This is a demonstration Node.js real-time multi-player quiz. It launches:

2 replicated HTTP web servers (Node.js Express app)
3 replicated Web Socket servers (Node.js application)
a PostgreSQL database server
a Traefic reverse proxy and load balancer to direct traffic to the HTTP or WS servers
optionally, an Adminer database client.

Requirements

Docker and Docker Compose are required to run this demonstration.

Configuration

Database and application settings can be edited in the .env file.

Launch in development mode

Run the following command from the project root directory (nodequiz) to start all servers with live reloading when files are updated:

docker-compose up

Then open http://quiz.localhost/ in your browser and start or join a quiz.

The Traefic load balancer dashboard is accessed at http://localhost:8080/

The Adminer database client is accessed at http://adminer.localhost/ with the following credentials:

System: PostgreSQL
Server: dbserver (or host.docker.internal or your PC's IP address)
Username: quizuser
Password: quizpass
Database: quiz

You can also use pgAdmin if you require a more sophisticated database client.

If using another database client application, use localhost as the server name.

Use a Node.js debugging client

To debug, you must bypass the load balancer and attach to a single instance of the running application. View the running containers with:

docker container ls

Note the PORTS mappings and NAMES:

PORTS                                              NAMES
0.0.0.0:59961->8001/tcp, 0.0.0.0:59962->9229/tcp   nodequiz_ws_1
0.0.0.0:59956->8001/tcp, 0.0.0.0:59957->9229/tcp   nodequiz_ws_2
0.0.0.0:59958->8001/tcp, 0.0.0.0:59959->9229/tcp   nodequiz_ws_3
0.0.0.0:59952->8000/tcp, 0.0.0.0:59953->9229/tcp   nodequiz_web_1
0.0.0.0:59954->8000/tcp, 0.0.0.0:59955->9229/tcp   nodequiz_web_2
0.0.0.0:5432->5432/tcp                             dbserver
0.0.0.0:59951->8080/tcp                            nodequiz_adminer_1
0.0.0.0:80->80/tcp, 0.0.0.0:8080->8080/tcp         nodequiz_reverse-proxy_1

You can view the web pages on nodequiz_web_1 by loading http://localhost:59961/

Similarly, you can debug the code on the same server at http://localhost:59962/. For example, open chrome://inspect/ in Google Chrome, click Configure next to Discover network targets and add localhost:59962.

Launch in production mode

Run the following command from the project root directory (nodequiz) to start all servers in production mode:

docker-compose -f ./docker-compose-production.yml up

Note: Docker Compose mounts the ./libshared directory into both the web and ws containers. To create stand-alone containers, you should must copy this directory into the web and ws directories.

Then open http://quiz.localhost/ in your browser.

Stop all services

Stop the applications from the same directory using the command:

docker-compose down