Webhook Service

A scalable and reliable webhook delivery service that handles event notifications with fair queueing and retry mechanisms.

Prerequisites

• Docker
• Docker Compose

That's it! You don't need Go, PostgreSQL, or any other dependencies installed locally.

Quick Start

Using the start script (Recommended)

# Make the script executable (Unix-like systems)
chmod +x start.sh

# Start the service
./start.sh

Using Docker Compose directly

# Start the services
docker compose up --build

# Or run in detached mode
docker compose up -d --build

# View logs
docker compose logs -f

# Stop services
docker compose down

Configuration

All configuration is done through environment variables. You can override the defaults by creating or modifying the .env file in the project root. Here are the key configuration options:

# HTTP server configuration
PORT=8080
APP_ENV=local

# Database configuration
WS_DB_HOST=localhost
WS_DB_PORT=5432
WS_DB_DATABASE=webhook_service
WS_DB_USERNAME=admin
WS_DB_PASSWORD=password1234
WS_DB_SCHEMA=public

# Worker and queue configuration
QUEUE_BUFFER_SIZE=100
MIN_WORKERS=5
MAX_WORKERS=20
MIN_REQUEST_WORKERS=5
MAX_REQUEST_WORKERS=20
REQUEST_BUFFER_SIZE=1000

# Retry configuration
INITIAL_DELAY=1s
MAX_DELAY=10s
MAX_RETRIES=3
SHUTDOWN_TIMEOUT=10s

Note: When running with Docker Compose, the database host is automatically set to psql_ws (the service name in docker-compose.yml).

Testing the Service

Once the service is running, you can test it using curl:

# Health check
curl http://localhost:8080/health

# Send a test webhook event
curl -X POST http://localhost:8080/webhooks/events \
-H "Content-Type: application/json" \
-d '{
  "event_name": "subscriber.created",
  "event_time": "2024-03-19T14:15:22Z",
  "webhook_id": "test-webhook-id",
  "subscriber": {
    "id": "sub123",
    "status": "active",
    "email": "[email protected]",
    "source": "manual",
    "first_name": "John",
    "last_name": "Doe",
    "segments": [],
    "custom_fields": {},
    "optin_ip": "127.0.0.1",
    "optin_timestamp": "2024-03-19T14:15:22Z",
    "created_at": "2024-03-19T14:15:22Z"
  }
}'

Documentation

Architecture

For detailed information about the system architecture, components, and design decisions, please see the Architecture Documentation.

Key architectural features:

• Reliability: Implements retry mechanism with exponential backoff
• Scalability: Uses worker pools and is horizontally scalable
• Fairness: Implements fair queueing to prevent large customers from flooding the system

Benchmarking

For information about benchmarking the webhook service, including performance testing methodologies, tools, and build instructions, please see the Benchmarking Documentation.

Project Structure

• cmd/: Application entry points
  • app/: Main webhook service application
  • benchmark/: Performance testing tools
  • mockserver/: Mock webhook target server
• internal/: Internal packages
  • config/: Application configuration
  • database/: Database connection and migrations
  • model/: Data models and validation
  • repository/: Data access layer
  • server/: HTTP server and request routing
  • service/: Business logic and worker pools
• scripts/: Utility scripts
• start.sh: Convenience script for starting the service
• docker-compose.yml: Docker Compose configuration
• Dockerfile: Docker build configuration
• .env: Environment variable configuration

License

This project is licensed under the MIT License - see the LICENSE file for details.