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Zero Sync Server ​

Overview ​

Zero Sync server provides real-time data synchronization capabilities for our applications.

Docker Configuration ​

Container Details ​

  • Image: rocicorp/zero:latest
  • Container Name: oee-zero_cache-1
  • Internal Port: 4848
  • Host Port: 4848
  • Protocol: HTTP/WebSocket

Docker Compose ​

yaml
services:
  zero_cache:
    image: rocicorp/zero:latest
    container_name: oee-zero_cache-1
    ports:
      - "4848:4848"
    command: /bin/sh -c 'npx zero-cache'
    environment:
      - NODE_ENV=production
    restart: unless-stopped

Nginx Configuration ​

Domain Setup ​

Domain: zero.hargunrana.com

Location: /etc/nginx/sites-available/zero.hargunrana.com

nginx
server {
    server_name zero.hargunrana.com;

    location / {
        proxy_pass http://localhost:4848;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_read_timeout 86400;
    }

    listen 443 ssl;
    ssl_certificate /etc/letsencrypt/live/zero.hargunrana.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/zero.hargunrana.com/privkey.pem;
    include /etc/letsencrypt/options-ssl-nginx.conf;
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
}

server {
    if ($host = zero.hargunrana.com) {
        return 301 https://$host$request_uri;
    }

    listen 80;
    server_name zero.hargunrana.com;
    return 404;
}

Enable the site:

bash
sudo ln -sf /etc/nginx/sites-available/zero.hargunrana.com /etc/nginx/sites-enabled/
sudo nginx -t
sudo systemctl reload nginx

Access Details ​

Connection URL ​

https://zero.hargunrana.com

WebSocket Connection ​

javascript
const ws = new WebSocket('wss://zero.hargunrana.com');

Firewall Configuration ​

No additional firewall rules needed - uses standard HTTPS port 443 which is already open.

Monitoring ​

Check Container Status ​

bash
docker ps | grep zero
docker logs oee-zero_cache-1

Check Service Health ​

bash
curl https://zero.hargunrana.com

Monitor Connections ​

bash
docker stats oee-zero_cache-1

Troubleshooting ​

Container Issues ​

bash
# Restart container
docker restart oee-zero_cache-1

# View logs
docker logs -f oee-zero_cache-1

# Check resource usage
docker stats oee-zero_cache-1

Connection Issues ​

bash
# Test local connection
curl http://localhost:4848

# Check nginx proxy
sudo tail -f /var/log/nginx/access.log
sudo tail -f /var/log/nginx/error.log

Common Issues ​

  1. WebSocket connection fails: Check nginx upgrade headers
  2. 502 Bad Gateway: Container may be down, check with docker ps
  3. SSL errors: Verify certificates are valid and not expired

Integration ​

Client Configuration ​

javascript
import { Zero } from '@rocicorp/zero';

const zero = new Zero({
  server: 'https://zero.hargunrana.com',
  // Additional configuration
});

Security Notes ​

  • SSL/TLS enabled by default
  • WebSocket connections are encrypted
  • Consider adding authentication layer
  • Monitor for unusual traffic patterns