This application is a demonstration to show how web-sockets can be made to work with multiple replicas of a chat application in a scalable environment. It is inspired by this repository with some modifications in front end design and with actual compose file for docker stack deploy ...
Socket.io is extremely powerful when it comes to communicating between the browser and a server in real-time. However, the problem of scaling quickly arises with the situations of very high numbers of clients or the need to implement load balancing. This problem can be easily and effectively addressed with RabbitMQ. This method also allows for a very extendable architecture when the project's goals inevitably grow and/or change.
To get the docker image from docker hub, execute following command:
docker pull saqibahmed515/chat:1.0
To deploy the image with rabbitMQ and visualizer, you must have a swarm initialized with
docker swarm init
A single node swarm will serve the purpose of demonstration. Then simply execute
docker stack deploy -c docker-compose.yml test
It will start the chat application at port 3000. You can see the visualizer at port 8080. It will take around 10-20 seconds for the whole stack to become fully available. To see the services' status, execute
docker service ls
In the project's root directory, run following commands to get the dependencies resolved.
npm install
bower install
Then copy the resulting directory bower_components in the public folder if it isn't loaded there already.
Finally execute following command to build the image:
docker build -t saqibahmed515/chat:1.0 .
You can see the demonstration of the chat from different host containers in following animation:
The deployment has following components in this case:
