Flask-Based Microservices with Centralized Logging

This project demonstrates a microservice architecture built with Flask in Python, featuring a centralized logging system using Kafka and Elasticsearch. The architecture consists of three main services—User Service, Hotel Service, and Reservation Service—along with an API Gateway that handles routing and logging.

Project Structure

otel_rezervasyon/
├── api_gateway/
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
├── user_service/
│   ├── app.py
│   ├── Dockerfile
│   ├── requirements.txt
│   └── user_data.py
├── hotel_service/
│   ├── app.py
│   ├── Dockerfile
│   ├── requirements.txt
│   └── hotel_data.py
├── reservation_service/
│   ├── app.py
│   ├── Dockerfile
│   ├── requirements.txt
│   └── reservation_data.py
├── common/
│   ├── kafka_service.py
│   ├── elasticsearch_service.py
│   └── database.py
├── docker-compose.yml
└── otel-collector-config.yaml

Features

• User Service: Manages user registration and authentication.
• Hotel Service: Handles hotel data management.
• Reservation Service: Manages hotel reservations.
• API Gateway: Routes requests to the appropriate services and logs actions centrally.
• Centralized Logging: Uses Kafka to collect logs from all services and Elasticsearch to store and analyze logs.
• Monitoring and Visualization: Uses Kibana to visualize logs and monitor system behavior.

Technologies Used

• Flask: Python micro web framework.
• Kafka: Distributed messaging system for log aggregation.
• Elasticsearch: Search and analytics engine for storing and querying logs.
• Kibana: Data visualization tool for Elasticsearch.
• Docker: Containerization platform to manage the microservices.

Getting Started

Prerequisites

• Docker and Docker Compose installed on your machine.

Build and start the services using Docker Compose:

docker-compose up --build

Access the services via the API Gateway:

• User Service: http://localhost:5003/user/<action>
• Hotel Service: http://localhost:5003/hotel/<action>
• Reservation Service: http://localhost:5003/reservation/<action>

Logging and Monitoring

• Kafka: Log messages are sent to the otel-logs topic.
• Elasticsearch: Logs are stored in the otel-logs index.
• Kibana: Visualize logs at http://localhost:5601.

Example Requests

• Register a User:

  curl -X POST http://localhost:5003/user/register -H "Content-Type: application/json" -d '{"username": "john_doe", "password": "secure_password"}'

• Login a User:

  curl -X POST http://localhost:5003/user/login -H "Content-Type: application/json" -d '{"username": "john_doe", "password": "secure_password"}'