LogProx 🏗️

HTTP proxy with conditional logging and request control

🚀 Quick Start

Installation

# Build from source
git clone https://github.com/bryan-lott/logprox.git
cd logprox
cargo build --release

Basic Usage

# Start with default config
./target/release/logprox

# Specify custom config
./target/release/logprox --config my-config.yaml

# Set environment variables
PORT=8080 CONFIG_FILE=config.yaml ./target/release/logprox

Simple Example

Create config.yaml:

logging:
  default: false
  rules:
    - name: "Monitor API calls"
      match_conditions:
        path:
          patterns: ["/api/.*"]
      capture:
        method: true
        path: true
        timing: true

Start LogProx and test:

# Proxy format: http://host:port/https://upstream-domain/path
curl -X GET "http://localhost:3000/https://httpbin.org/api/test"

✨ Features

• 📝 Conditional Logging: Log requests based on path, method, headers, body
• 🛡️ Request Control: Drop requests based on configurable rules
• 🔄 Hot Reload: Update configuration without restarting
• 📊 Built-in Monitoring: Health checks and configuration endpoints

🏗️ Architecture

┌─────────────┐    ┌───────────┐    ┌────────────────┐
│   Client    │───▶│  LogProx  │───▶│  Upstream API  │
│ Application │    │           │    │                │
└─────────────┘    └───────────┘    └────────────────┘
                          │
                          ▼
                    ┌────────────┐
                    │   Logs &   │
                    │  Metrics   │
                    └────────────┘

⚙️ Configuration

LogProx uses YAML configuration with environment variable support (${VAR_NAME}).

Environment Variables

Variable	Default	Description
PORT	3000	Server port
CONFIG_FILE	config.yaml	Configuration file path

Quick Reference

logging:
  default: false
  rules:
    - name: "API Monitoring"
      match_conditions:
        path: { patterns: ["/api/.*"] }
        methods: ["POST", "PUT"]
      capture: { method: true, path: true, timing: true }

drop:
  default: false
  rules:
    - name: "Block Bots"
      match_conditions:
        headers: { "user-agent": ".*bot.*" }
      response: { status_code: 403, body: "Access denied" }

response_logging:
  default: false
  rules:
    - name: "Log Errors"
      match_conditions:
        status_codes: [400, 401, 403, 404, 500, 502, 503]
      capture: { status_code: true, timing: true }

Request Format

Proxy requests use URL path encoding:

http://localhost:3000/https://api.example.com/users/123
                    ↑
                    Encoded upstream URL

Pattern Matching

Regex Examples:

• .* - Match any characters
• ^/api/ - Match paths starting with /api/
• \d+ - Match one or more digits
• (option1|option2) - Match either option

Matching Logic:

• Path patterns: At least one must match
• Methods: Must be in methods list (if specified)
• Headers: All specified headers must match
• Body patterns: At least one must match
• Rule evaluation: First match wins

🔌 API Reference

Endpoint	Method	Response
/health	GET	200 OK with body "OK"
/config	GET	Current JSON configuration
/config/docs	GET	Configuration documentation
/config/reload	POST	Reload configuration

Usage Examples

# Health check
curl http://localhost:3000/health

# Get current config
curl http://localhost:3000/config | jq .

# Reload configuration
curl -X POST http://localhost:3000/config/reload

# View documentation
curl http://localhost:3000/config/docs

🔧 Troubleshooting

Configuration Issues

# Validate YAML syntax
yamllint config.yaml

# Enable debug logging
RUST_LOG=debug ./target/release/logprox

Common Problems

• Invalid proxy format: Use /https://domain/path format
• Regex errors: Test patterns with regex debugger
• Permission denied: Check config file permissions

🤝 Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines.

📄 License

GNU GPLv3 © Bryan Lott