Setup

The installation has been well tested to work on Ubuntu 16.04. Issues have been reported with installation on windows.

Install latest version of docker in your system.
Clone this project; actually you only require the docker-stack.yml file and the other two *.env files : )
Change the env variables in worker.env and server.env as per your required variables. Note the frontend service will start on port 80 only due to image.
Run the command in terminal docker swarm init to initialize a docker swarm.
Now you can connect multiple nodes to this swarm using the key generated by running above command.
Execute docker stack deploy -c docker-stack.yml cp and as easy as that.
All the services will be up and running in a few minutes (depending upon your internet connectivity).
You can check for running service by command docker service ls
Any of these four running services can easily be scaled by writing docker service scale cp_<serive_name>=<number_of_replicas_required>

Services

The app has mainly five services running independently which can be scaled individually as per requirement.
Frontend - The frontend is made using ReactJS uses API endpoints developed in App server.
Server(Backend) - Backed or API server is based on NodeJS. We are using MongoDB for database.
Worker - It's main task is to keep an eye on the queue to keep updating the click tracks.
Redis server - This server is responsible to maintain LRU cache for hash:url pairs and a queue that is used to
MongoDB - MongoDB service whhich can easily be scaled by clustering multiple instances. track clicks on a hash link