# Configuring and using WebSocket connections

> Set up WebSocket connections for real-time apps on a VPS, with Python and Node.js server and client examples.

Source: https://helpcenter.ruachost.com/developers/guides/configuring-and-using-websocket-connections/

## Configuring and Using WebSocket Connections on VPS or Dedicated Servers

WebSockets allow persistent, two-way communication between a browser and server over a single TCP socket, enabling real-time, responsive web applications.

> **Note:** WebSockets are **not supported** on shared hosting accounts.

### Supported Hosting Plans

- Managed or unmanaged VPS
- Dedicated servers

### Step 1: Web Server Configuration

#### Without Root Access

Open a support ticket in the [Ruachost client area](https://dashboard.ruachost.com/submitticket.php) with:

- Domain/URL for WebSocket proxy
- Port number of your WebSocket server

#### With Root Access

You can configure your web server directly:

- **Apache:** [mod_proxy_wstunnel documentation](https://httpd.apache.org/docs/2.4/mod/mod_proxy_wstunnel.html)
- **Nginx:** [WebSocket documentation](https://nginx.org/en/docs/http/websocket.html)
- Other web servers: refer to their respective documentation

### Step 2: WebSocket Server Application

#### Python Server Example

1. Ensure Python ≥3.9 is installed.
2. Create a virtual environment and install the `websockets` library:

```
ssh user@server
python3 -m venv websocketenv
cd websocketenv
source bin/activate
pip install websockets
```

3. Create `server.py` with the following content:

```
#!/usr/bin/env python

from websockets.asyncio.server import serve

async def echo(websocket):
    async for message in websocket:
        print('Received [' + message + ']')
        await websocket.send(message)

async def main():
    async with serve(echo, "localhost", 5678) as server:
        await server.serve_forever()

if __name__ == "__main__":
    asyncio.run(main())
```

4. Start the server:

```
python3 server.py
```

#### Node.js Server Example

1. Ensure Node.js ≥16 is installed.
2. Install the `ws` library:

```
ssh user@server
npm install ws
Create server.mjs:

const wss = new WebSocketServer({ port: 5678 });

wss.on('connection', function connection(ws) {
  ws.on('error', console.error);

  ws.on('message', function message(data) {
    console.log('Received [%s]', data);
    ws.send(data.toString());
  });
});
```

```
```

4. Start the server:

```
node server.mjs
```

> **Important:** Save with `.mjs` extension.

### Step 3: WebSocket Client

Create a test HTML page:

```
<!DOCTYPE html>
<html>
<head>
  <title>WebSocket test</title>
<script>
"use strict";

function webSocketTest() {
  let socket = new WebSocket("wss://example.com/");

  socket.onopen = function(event) {
    alert("Connection established");
    socket.send("Hello from WebSockets");
  };

  socket.onmessage = function(event) {
    alert(`Received data from server: ${event.data}`);
  };

  socket.onclose = function(event) {
    if (event.wasClean) {
      alert(`Connection closed cleanly, code=${event.code} reason=${event.reason}`);
    } else {
      alert('Connection died');
    }
  };

  socket.onerror = function(event) {
    alert(`[error]`);
  };
}
</script>
</head>
<body onload="webSocketTest()">
  <p>WebSocket test</p>
</body>
</html>
```

- Replace `example.com` with your server’s domain or IP.
- Load this page in a browser to test the WebSocket connection.

### Step 4 (Optional): Make the Server Persistent

Create a systemd service to auto-start your WebSocket server.

#### Python Service Example

```
/etc/systemd/system/websocket-server.service:

[Unit]
Description=WebSocket Server Daemon
After=network-online.target

[Service]
ExecStart=/home/username/sockenv/bin/python3 /home/username/sockenv/server.py
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target
```

#### Node.js Service Example

```
[Unit]
Description=WebSocket Server Daemon
After=network-online.target

[Service]
ExecStart=/home/username/bin/node /home/username/server.mjs
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target
```

#### Commands to Enable the Service

```
chmod 664 /etc/systemd/system/websocket-server.service
systemctl --system daemon-reload
systemctl start websocket-server.service
systemctl status websocket-server.service
systemctl enable websocket-server.service
```

Your WebSocket server will now start automatically on boot and restart if it crashes.

This setup provides a full WebSocket stack: server, client, and persistent system service.