Proxy

Provides an HTTP proxy while still enforcing your app's security

Technology

The proxy module provides secure HTTP proxy functionality for Project Forge applications. It allows your application to proxy requests to external services while maintaining security controls and consistent routing patterns.

Overview

This module enables applications to act as a secure HTTP proxy, forwarding requests to configured external services while:

Enforcing Security: Maintains your application’s authentication and authorization
URL Rewriting: Automatically rewrites relative URLs in responses to maintain proper routing
Header Management: Filters and manages HTTP headers for security
Service Management: Dynamically register and manage proxy destinations

⚠️ Security Notice: This module is marked as “dangerous” as it can expose your application to external services. Use with proper authentication and validation.

Key Features

Secure Proxying

Filters dangerous HTTP headers (Connection, Keep-Alive, etc.)
Adds “Proxied” header to identify proxy requests
Maintains request context and logging

URL Rewriting

Automatically rewrites href="/..." and src="/..." attributes
Ensures proxied content links work correctly within your application
Maintains relative path integrity

Dynamic Service Management

Register and remove proxy destinations at runtime
List all configured proxy services
Per-service URL configuration

Configuration

The proxy service is initialized with:

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// Create proxy service with URL prefix and initial services
proxyService := proxy.NewService("/proxy", map[string]string{
    "api": "http://localhost:8080",
    "docs": "https://docs.example.com",
})

// Add to application state
as.Services.Proxy = proxyService

Usage

Basic Setup

Initialize the service in your application startup:

proxy := proxy.NewService("/proxy", initialProxies)

Wire up routes in your router configuration:

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// Add proxy routes (typically in routes/proxy.go)
mux.HandleFunc("/proxy", clib.ProxyIndex)
mux.HandleFunc("/proxy/{svc}/{path:.*}", clib.ProxyHandle)

Managing Proxy Services

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// Add a new service
proxyService.SetURL("newservice", "https://api.example.com")

// Remove a service
proxyService.Remove("oldservice")

// List all services
services := proxyService.List()

Request Flow

Client makes request to /proxy/{service}/{path}
Proxy service looks up the target URL for {service}
Request is forwarded to {target_url}/{path}
Response is processed and URLs are rewritten
Modified response is returned to client

Security Considerations

Authentication: Proxy requests should be authenticated through your application’s normal auth flow
Authorization: Consider implementing service-specific access controls
Input Validation: Validate service names and paths to prevent abuse
Network Access: Ensure proxied services are on trusted networks
Header Filtering: The module filters dangerous headers but review for your specific needs

Source Code

Repository: https://github.com/kyleu/projectforge/tree/main/module/proxy
License: CC0 (Public Domain)
Author: Kyle U (kyle@kyleu.com)