SimpleHTTPRedirector

A lightweight, high-performance HTTP redirect service with JSON-based configuration. Perfect for managing domain redirects in containerized environments like Coolify, or behind reverse proxies like Traefik.

Features

• JSON Configuration - Simple, declarative redirect rules without environment variable complexity
• Multiple Sources per Rule - Redirect multiple domains to a single target
• Flexible Redirect Types - Support for permanent (301), temporary (302), or any 3xx status code
• Path & Query Preservation - Optionally preserve URL paths and query parameters
• Wildcard Support - Match subdomains with *.domain.com patterns
• Auto www Handling - Rules for domain.com automatically match www.domain.com
• Proxy-Aware - Correctly handles X-Forwarded-Host headers from reverse proxies
• Trusted Proxy Mode - Configurable trust for proxy headers (TRUST_PROXY)
• Rate Limiting - Built-in protection against request flooding
• Secure by Default - Target URL validation prevents open redirect vulnerabilities
• Lightweight - ~30MB Docker image based on Alpine Linux
• Health Endpoint - Built-in /health endpoint for container orchestration

Quick Start

Using Docker Compose (Coolify)

# Clone the repository
git clone https://github.com/bauer-group/CS-SimpleHTTPRedirector.git
cd CS-SimpleHTTPRedirector

# Create your configuration
cp config/redirects.example.json config/redirects.json
# Edit config/redirects.json with your redirect rules

# Start the service
docker compose up -d

Using Docker Compose (Traefik)

# Copy environment template
cp .env.example .env
# Edit .env with your settings

# Start with Traefik labels
docker compose -f docker-compose.traefik.yml up -d

Local Development

# Build and run with port mapping
docker compose -f docker-compose.development.yml up --build

# Test a redirect
curl -I -H "Host: example.com" http://localhost:8080/

Configuration

Redirect Rules (config/redirects.json)

The configuration file is a JSON array of redirect rules:

[
  {
    "source": ["old-domain.com", "www.old-domain.com"],
    "target": "https://new-domain.com",
    "type": "permanent",
    "preserve_path": true,
    "preserve_query": true
  },
  {
    "source": ["campaign.example.com"],
    "target": "https://shop.example.com/promo",
    "type": "temporary",
    "preserve_path": false,
    "preserve_query": true
  },
  {
    "source": ["*.legacy.com"],
    "target": "https://modern.com",
    "type": "308",
    "preserve_path": true,
    "preserve_query": false
  }
]

Rule Properties

Property	Type	Required	Default	Description
source	string[]	Yes	-	Array of source hostnames to match
target	string	Yes	-	Target URL to redirect to
type	string	No	permanent	Redirect type (see below)
preserve_path	boolean	No	false	Append original path to target
preserve_query	boolean	No	false	Append query parameters to target

Redirect Types

Type	HTTP Status	Use Case
permanent	301	Permanent domain moves (SEO-friendly)
temporary	302	Temporary redirects, A/B testing
303	303	Redirect after POST (See Other)
307	307	Temporary redirect preserving method
308	308	Permanent redirect preserving method

Source Matching

Sources are matched in the following order:

1. Exact match - docs.example.com matches docs.example.com
2. Wildcard match - *.example.com matches anything.example.com
3. www handling - example.com also matches www.example.com (and vice versa)

Path & Query Preservation

Example with preserve_path: true:

source.com/products/item-123 → target.com/products/item-123

Example with preserve_query: true:

source.com?ref=campaign&id=42 → target.com?ref=campaign&id=42

Example with target path and preservation:

{
  "source": ["old-docs.com"],
  "target": "https://new-site.com/documentation/",
  "preserve_path": true
}

old-docs.com/api/v2 → new-site.com/documentation/api/v2

Docker Compose Files

File	Purpose	Network
docker-compose.yml	Coolify deployment	Coolify-managed
docker-compose.traefik.yml	Standalone with Traefik	External proxy network
docker-compose.development.yml	Local development	Host port 8080

Environment Variables

Copy .env.example to .env and configure as needed:

# Server settings (all compose files)
TRUST_PROXY=true               # Trust X-Forwarded-* headers (default: true)

# For docker-compose.traefik.yml
STACK_NAME=redirector          # Container name prefix
PROXY_NETWORK=proxy            # External Traefik network
CONFIG_PATH=./config           # Config directory path
REDIRECT_HOST_RULE=Host(`...`) # Traefik routing rule

# For docker-compose.development.yml
HOST_PORT=8080                 # Local port mapping

Security Settings

Variable	Default	Description
TRUST_PROXY	true	Trust X-Forwarded-* headers from reverse proxy. Set to false if exposed directly to the internet.

Health Check

The service exposes a health endpoint at /health:

curl http://localhost:8080/health
# {"status":"healthy"}

Logging

All redirects are logged with source, target, and status code:

2025/01/15 10:30:45 Loaded 3 redirect rules
2025/01/15 10:30:45   [old-domain.com www.old-domain.com] -> https://new-domain.com (301, path=true, query=true)
2025/01/15 10:30:45 Starting HTTP Redirector on port 8080
2025/01/15 10:31:02 Redirecting old-domain.com/page -> https://new-domain.com/page (301)

Coolify Deployment

1. Add repository as a Docker Compose project
2. Select docker-compose.yml
3. Configure domains in Coolify's GUI (add all source domains)
4. Mount config volume or use Coolify's file manager to edit config/redirects.json
5. Deploy

Building

# Build the Docker image
docker build -t simple-http-redirector:latest ./src

# Build with specific Go version
docker build --build-arg GO_VERSION=1.25 -t simple-http-redirector:latest ./src

Architecture

┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│   Client        │────▶│  Traefik/Proxy  │────▶│  Redirector     │
│                 │     │                 │     │                 │
│                 │◀────│  X-Forwarded-*  │◀────│  301/302/3xx    │
└─────────────────┘     └─────────────────┘     └─────────────────┘
                                                        │
                                                        ▼
                                                ┌─────────────────┐
                                                │ redirects.json  │
                                                └─────────────────┘

License

MIT License - see LICENSE for details.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Submit a pull request

Support

• Issues: GitHub Issues
• Documentation: GitHub Wiki