A scalable notification service that supports email, SMS, and Slack channels with at-least-once delivery guarantee.
This system provides a centralized service for sending notifications across multiple channels with horizontal scalability and reliability. Built with Go, it uses Kafka as a message broker to ensure reliable delivery.
- Notification Orchestrator: API service that receives and routes notification requests
- Channel Workers: Dedicated services for email, SMS, and Slack delivery
- Kafka: Message broker ensuring reliable message delivery
- Prometheus: Metrics and monitoring
- Docker and Docker Compose
- Clone the repository:
git clone https://github.com/Givko/NotificationSystem
cd NotificationSystem- Start all services:
docker-compose up --waitOR build all services from source:
docker-compose up --build --waitOR run only dependencies for local development:
docker-compose up zookeeper kafka kafka-init- Send a test notification:
curl -X POST http://localhost:8081/api/v1/notifications \
-H "Content-Type: application/json" \
-d '{
"recipient": "John Doe",
"recipient_id": "user123",
"sender": "Service XYZ",
"sender_id": "service_xyz",
"subject": "Important Update",
"message": "Your order has been shipped!",
"channel": "email"
}'| Service | Port | Description |
|---|---|---|
| notification-orchestrator | 8081 | Main API service |
| email-worker | 8080 | Processes email notifications |
| sms-worker | 8082 | Processes SMS notifications |
| slack-worker | 8083 | Processes Slack notifications |
| kafka | 9092 | Message broker |
| prometheus | 9090 | Metrics and monitoring |
The system uses config.yaml files for configuration(/config/config.yaml). Key settings for notification orchestrator:
server:
port: 8080
kafka:
bootstrap-servers: localhost:9092 # for using docker use kafka:29092
notifications:
channel-topics:
slack: slack-worker
email: email-worker
sms: sms-workergo test ./...project-root/
├── go.mod # Single go.mod file for the entire project
├── go.sum # Dependencies lockfile
├── cmd/ # Contains main packages for each executable
│ ├── email-worker/
│ │ └── main.go # Main entry point for email-worker service
│ └── notification-orchestrator/
│ └── main.go # Main entry point for notification-orchestrator service
├── internal/ # Private application code
│ ├── email-worker/ # Email-specific code
│ └── notification/ # Notification-specific code
├── pkg/ # Public libraries that can be imported by other projects
│ └── shared/ # Shared code between services
└── docker/ # Dockerfiles for each service
├── email-worker/
│ └── Dockerfile
└── notification-orchestrator/
└── Dockerfile
This project uses GitHub Actions for continuous integration and delivery. The workflow includes:
- Linting: Code quality checks using golangci-lint
- Testing: Automated tests with coverage reports
- Building: Compilation verification for all services
- Docker Images: Building and pushing Docker images to Docker Hub
Official Docker images are available at:
Pull images directly:
docker pull jivkomilev/notification-orchestrator:latest
docker pull jivkomilev/email-worker:latest
docker pull jivkomilev/sms-worker:latest
docker pull jivkomilev/slack-worker:latestAccess Prometheus metrics at: http://localhost:9090