# Socket.IO Chat with nginx & redis

A simple chat demo for socket.io

## How to use

Install [Docker Compose](https://docs.docker.com/compose/install/), then:

```
$ docker-compose up -d
```

And then point your browser to `http://localhost:3000`.

This will start four Socket.IO nodes, behind a nginx proxy which will loadbalance the requests (using the IP of the client, see [ip_hash](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#ip_hash)).

Each node connects to the redis backend, which will enable to broadcast to every client, no matter which node it is currently connected to.

```
# you can kill a given node, the client should reconnect to another node
$ docker-compose stop server-george
```

A `client` container is included in the `docker-compose.yml` file, in order to test the routing.

You can create additional `client` containers with:

```
$ docker-compose up -d --scale=client=10 client
# and then
$ docker-compose logs client
```

## Features

- Multiple users can join a chat room by each entering a unique username
on website load.
- Users can type chat messages to the chat room.
- A notification is sent to all users when a user joins or leaves
the chatroom.