Reverse Proxy Configuration Guide

This comprehensive guide will help you configure various reverse proxy servers to work seamlessly with Ltranslate for automatic website translation.

Overview

Reverse proxy configuration allows you to integrate Ltranslate translation services with any web server or proxy solution. This guide covers the most popular proxy servers and CDN services.

Nginx Reverse Proxy

Basic Configuration

server {
    listen 80;
    server_name your-domain.com;
    
    # Original content
    location / {
        proxy_pass http://your-backend;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
    
    # Translation service
    location ~ ^/(zh-cn|ja|ko|es|fr|de)/ {
        proxy_pass https://engine.ltranslate.cn;
        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 api-key "YOUR_API_KEY";
        proxy_set_header source-lang "en";
        proxy_set_header target-lang $1;
    }
}

Apache Reverse Proxy

Enable Required Modules

# Enable proxy modules
sudo a2enmod proxy
sudo a2enmod proxy_http
sudo a2enmod proxy_balancer
sudo a2enmod lbmethod_byrequests
sudo systemctl restart apache2

Virtual Host Configuration

<VirtualHost *:80>
    ServerName your-domain.com
    
    # Original content
    ProxyPreserveHost On
    ProxyPass / http://your-backend/
    ProxyPassReverse / http://your-backend/
    
    # Translation service
    ProxyPassMatch ^/(zh-cn|ja|ko|es|fr|de)/ https://engine.ltranslate.cn/
    ProxyPassReverseMatch ^/(zh-cn|ja|ko|es|fr|de)/ https://engine.ltranslate.cn/
    
    # Set custom headers
    RequestHeader set api-key "YOUR_API_KEY"
    RequestHeader set source-lang "en"
</VirtualHost>

Cloudflare Configuration

Origin Rules

Use Cloudflare Origin Rules to route translation requests to Ltranslate:

# Example Cloudflare Worker for translation
addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request))
})

async function handleRequest(request) {
  const url = new URL(request.url)
  
  // Check if this is a translation request
  if (url.pathname.match(/^\/(zh-cn|ja|ko|es|fr|de)\//)) {
    const targetLang = url.pathname.split('/')[1]
    const translationUrl = `https://engine.ltranslate.cn${url.pathname}`
    
    const translationRequest = new Request(translationUrl, {
      method: request.method,
      headers: {
        ...request.headers,
        'api-key': 'YOUR_API_KEY',
        'source-lang': 'en',
        'target-lang': targetLang,
        'host': url.hostname
      }
    })
    
    return fetch(translationRequest)
  }
  
  // Forward original request
  return fetch(request)
}

HAProxy Configuration

Frontend and Backend Configuration

frontend https_frontend
    bind *:443 ssl crt /path/to/cert.pem
    bind *:80
    
    # ACL for translation requests
    acl is_translation_req path_beg /zh-cn/ /ja/ /ko/ /es/ /fr/ /de/
    
    # Route to translation service
    use_backend ltranslate_backend if is_translation_req
    default_backend your_backend

backend ltranslate_backend
    server ltranslate engine.ltranslate.cn:443 ssl
    http-request set-header api-key "YOUR_API_KEY"
    http-request set-header source-lang "en"
    http-request set-header target-lang %{+path;regsub(^\/([^\/]+).*,$1)}

backend your_backend
    server your_app localhost:8080

Traefik Configuration

Docker Compose Setup

version: '3.8'

services:
  traefik:
    image: traefik:v2.10
    command:
      - "--api.insecure=true"
      - "--providers.docker=true"
      - "--entrypoints.web.address=:80"
    ports:
      - "80:80"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock"

  your-app:
    image: your-app:latest
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.your-app.rule=Host(`your-domain.com`)"

  ltranslate:
    image: traefik/whoami
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.ltranslate.rule=Host(`your-domain.com`) && PathRegexp(`/zh-cn|ja|ko|es|fr|de}/`)"
      - "traefik.http.middlewares.ltranslate-headers.headers.customrequestheaders.api-key=YOUR_API_KEY"
      - "traefik.http.middlewares.ltranslate-headers.headers.customrequestheaders.source-lang=en"

Caddy Server Configuration

Caddyfile Setup

your-domain.com {
    # Handle translation requests
    handle_path /zh-cn* {
        reverse_proxy https://engine.ltranslate.cn {
            header_up api-key "YOUR_API_KEY"
            header_up source-lang "en"
            header_up target-lang "zh-cn"
        }
    }
    
    handle_path /ja* {
        reverse_proxy https://engine.ltranslate.cn {
            header_up api-key "YOUR_API_KEY"
            header_up source-lang "en"
            header_up target-lang "ja"
        }
    }
    
    # Original content
    reverse_proxy http://your-backend:8080
}

IIS Configuration

URL Rewrite Rules

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <rule name="Translation" stopProcessing="true">
                    <match url="^(zh-cn|ja|ko|es|fr|de)/(.*)" />
                    <action type="Rewrite" url="https://engine.ltranslate.cn/{R:0}" />
                    <serverVariables>
                        <set name="HTTP_API_KEY" value="YOUR_API_KEY" />
                        <set name="HTTP_SOURCE_LANG" value="en" />
                        <set name="HTTP_TARGET_LANG" value="{R:1}" />
                    </serverVariables>
                </rule>
            </rules>
        </rewrite>
    </system.webServer>
</configuration>

Security Considerations

Troubleshooting

Best Practices

• Implement caching to reduce API calls and improve performance
• Use connection pooling for better resource utilization
• Monitor proxy performance and set up health checks
• Implement proper logging and monitoring
• Test configuration changes in staging environment first