# DNS Setup Guide for candivista.com

This guide will help you configure your domain name `candivista.com` to point to your VPS at `168.231.108.135`.

## DNS Configuration

### Required DNS Records

You need to add the following DNS records in your domain registrar's DNS management panel:

#### A Records
```
Type: A
Name: @
Value: 168.231.108.135
TTL: 300 (or default)

Type: A  
Name: www
Value: 168.231.108.135
TTL: 300 (or default)
```

#### Optional CNAME Record (Alternative to www A record)
```
Type: CNAME
Name: www
Value: candivista.com
TTL: 300 (or default)
```

### DNS Propagation

After adding these records:
1. DNS changes can take 5 minutes to 48 hours to propagate globally
2. You can check propagation status at: https://www.whatsmydns.net/
3. Test locally with: `nslookup candivista.com` and `nslookup www.candivista.com`

## SSL Certificate Setup

### Option 1: Let's Encrypt (Recommended)

1. **Update your email in the SSL setup script:**
   ```bash
   # Edit nginx/ssl-setup.sh
   EMAIL="your-actual-email@example.com"
   ```

2. **Run the SSL setup:**
   ```bash
   chmod +x nginx/ssl-setup.sh
   ./nginx/ssl-setup.sh
   ```

3. **Deploy with SSL:**
   ```bash
   ./deploy-production.sh
   ```

### Option 2: Cloudflare (Alternative)

If you prefer using Cloudflare:

1. **Add your domain to Cloudflare**
2. **Point your nameservers to Cloudflare**
3. **Enable SSL/TLS encryption mode: "Full (strict)"**
4. **Update nginx configuration to use Cloudflare's origin certificates**

## Verification Steps

### 1. Check DNS Resolution
```bash
# Check A record
nslookup candivista.com
nslookup www.candivista.com

# Check from different locations
dig candivista.com @8.8.8.8
dig www.candivista.com @1.1.1.1
```

### 2. Test HTTP/HTTPS Access
```bash
# Test HTTP (should redirect to HTTPS)
curl -I http://candivista.com

# Test HTTPS
curl -I https://candivista.com

# Test www subdomain
curl -I https://www.candivista.com
```

### 3. SSL Certificate Verification
```bash
# Check SSL certificate
openssl s_client -connect candivista.com:443 -servername candivista.com

# Test SSL Labs rating
# Visit: https://www.ssllabs.com/ssltest/analyze.html?d=candivista.com
```

## Troubleshooting

### Common Issues

1. **DNS not resolving:**
   - Wait for propagation (up to 48 hours)
   - Check DNS records are correct
   - Verify TTL settings

2. **SSL certificate issues:**
   - Ensure domain points to your server before running SSL setup
   - Check firewall allows ports 80 and 443
   - Verify Let's Encrypt can reach your server

3. **Nginx not starting:**
   - Check nginx configuration: `nginx -t`
   - Check logs: `docker logs candidat-nginx`
   - Verify SSL certificates exist

### Useful Commands

```bash
# Check nginx configuration
docker exec candidat-nginx nginx -t

# View nginx logs
docker logs candidat-nginx

# Restart nginx
docker-compose restart nginx

# Check all services
docker-compose ps

# View all logs
docker-compose logs -f
```

## Security Considerations

1. **Firewall Configuration:**
   - Only allow ports 80, 443, and SSH (22)
   - Block direct access to backend ports (8083, 3000, 3306)

2. **SSL Security:**
   - The nginx configuration includes modern SSL settings
   - HSTS is enabled for security
   - Regular certificate renewal is automated

3. **Rate Limiting:**
   - API endpoints are rate limited
   - Admin endpoints have stricter limits
   - Connection limits per IP are enforced

## Monitoring

### Health Checks
- Application health: `https://candivista.com/health`
- Nginx status: `https://candivista.com/nginx_status` (internal only)

### Log Monitoring
```bash
# Real-time access logs
docker exec candidat-nginx tail -f /var/log/nginx/access.log

# Error logs
docker exec candidat-nginx tail -f /var/log/nginx/error.log

# Application logs
docker-compose logs -f backend
docker-compose logs -f frontend
```

## Next Steps

1. **Configure your domain DNS records** as described above
2. **Wait for DNS propagation** (check with whatsmydns.net)
3. **Update your email** in the SSL setup script
4. **Run the deployment script** to set up SSL and deploy
5. **Test your application** at https://candivista.com
6. **Set up monitoring** and regular backups