Blog Microservices Architecture

Description

This project is a microservices-based architecture for a blog platform. It was originally a monolithic application and has been refactored into microservices for better scalability and maintainability. It includes the following microservices:

• User Service: Handles user management (registration, login, etc.).
• Post Service: Manages blog posts (create, update, delete, view posts).
• Frontend Service: Provides the user interface for the blog platform.
• API Gateway: Routes client requests to the appropriate microservices.

The project is containerized using Docker and orchestrated with Kubernetes for deployment and scaling.

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Architecture Diagrams

Original Monolithic Architecture

graph TD
    Client[Client Browser]
    
    subgraph MonolithicApp[Monolithic Application]
        Frontend[Frontend/UI Layer]
        BusinessLogic[Business Logic Layer]
        DatabaseInteraction[Database Interaction Layer]
    end
    
    Database[(Database)]
    
    Client -->|HTTP/HTTPS| Frontend
    Frontend --> BusinessLogic
    BusinessLogic --> DatabaseInteraction
    DatabaseInteraction -->|SQL/NoSQL| Database
    Database -->|Data| DatabaseInteraction
    
    style MonolithicApp fill:#f5f5f5,stroke:#333,stroke-width:2px
    style Client fill:#b3e0ff,stroke:#333,stroke-width:2px
    style Frontend fill:#d9edf7,stroke:#333,stroke-width:1px
    style BusinessLogic fill:#dff0d8,stroke:#333,stroke-width:1px
    style DatabaseInteraction fill:#fcf8e3,stroke:#333,stroke-width:1px
    style Database fill:#ffe6cc,stroke:#333,stroke-width:2px

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New Microservices Architecture

graph TD
    Client[Client Browser]
    Gateway[API Gateway]
    
    subgraph FrontendService[Frontend Service]
        UI[UI Layer]
    end
    
    subgraph UserService[User Service]
        UserLogic[User Management]
        UserDB[(User Database)]
    end
    
    subgraph PostService[Post Service]
        PostLogic[Post Management]
        PostDB[(Post Database)]
    end
    
    Client -->|HTTP/HTTPS| Gateway
    Gateway -->|Route| UI
    Gateway -->|Route| UserLogic
    Gateway -->|Route| PostLogic
    
    UI <-->|API Calls| UserLogic
    UI <-->|API Calls| PostLogic
    
    UserLogic -->|CRUD| UserDB
    PostLogic -->|CRUD| PostDB
    
    style Client fill:#b3e0ff,stroke:#333,stroke-width:2px
    style Gateway fill:#ffb3b3,stroke:#333,stroke-width:2px
    style FrontendService fill:#d9edf7,stroke:#333,stroke-width:2px
    style UserService fill:#dff0d8,stroke:#333,stroke-width:2px
    style PostService fill:#fcf8e3,stroke:#333,stroke-width:2px
    style UserDB fill:#ffe6cc,stroke:#333,stroke-width:2px
    style PostDB fill:#ffe6cc,stroke:#333,stroke-width:2px

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Monolith to Microservices Conversion Process

Monolithic Architecture Overview:

Originally, the entire application was structured as a single monolithic architecture where:

• All services (user management, post management, and frontend) were part of a single codebase.
• There was a single database handling all operations, with no separation of concerns.

The major drawbacks of the monolithic architecture were:

• Scalability limitations: Scaling the entire application required scaling all services together.
• Maintenance difficulties: Code changes in one part of the application could affect other parts.
• Slow deployment cycles: Changes had to be tested and deployed as a whole.

Step-by-Step Conversion Process:

1. Identify Service Boundaries: The first step was to identify the major components of the application that could be separated into independent services:

   • User Management (User Service)
   • Blog Post Management (Post Service)
   • Frontend Presentation (Frontend Service)

2. Create Independent Microservices: Each identified service was refactored into its own Flask-based microservice:

   • User Service: Handles all user-related actions (e.g., registration, login).
   • Post Service: Manages blog post creation, editing, and viewing.
   • Frontend Service: Serves the frontend UI and interacts with the other services.

3. Decouple the Database: In the monolithic architecture, there was a single database. In the microservices architecture:

   • Each service has its own dedicated database (or schema) to ensure separation of data and responsibilities.

4. Introduce an API Gateway: The API Gateway was added to act as a single entry point for all client requests. It forwards requests to the respective microservices:

   • /users/ → User Service
   • /posts/ → Post Service
   • /frontend/ → Frontend Service

5. Containerization: Each service was containerized using Docker to ensure independent deployment, scalability, and resource isolation.

6. Orchestration with Kubernetes: Kubernetes was used to orchestrate the services, enabling easy scaling, deployment, and management of the microservices.

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Features

• Microservices architecture for scalability and maintainability.
• Dockerized services for easy container management.
• Kubernetes deployment for orchestration and scaling.
• API Gateway for routing and load balancing.
• Flask-based backend services.

Technologies Used

• Backend: Flask (Python)
• Containerization: Docker
• Orchestration: Kubernetes (Minikube or cloud-based Kubernetes)
• API Gateway: NGINX
• Databases: SQLite (or other database systems)
• Frontend: Flask templates or static HTML

Project Structure

blog-microservices-architecture/
│
├── user-service/             # User management microservice
│   ├── app.py               # Main application file
│   ├── models.py            # User database models
│   ├── requirements.txt     # Python dependencies
│   └── Dockerfile           # Docker configuration
│
├── post-service/            # Blog post management microservice
│   ├── app.py              # Main application file
│   ├── models.py           # Post database models
│   ├── requirements.txt    # Python dependencies
│   └── Dockerfile          # Docker configuration
│
├── frontend-service/        # Frontend microservice
│   ├── app.py              # Main application file
│   ├── static/             # Static files (HTML, CSS)
│   └── Dockerfile          # Docker configuration
│
├── api-gateway/            # API Gateway for routing
│   ├── nginx.conf          # NGINX configuration for routing
│   └── Dockerfile          # Docker configuration
│
├── kubernetes/             # Kubernetes deployment and service YAML files
│   ├── user-service-deployment.yaml
│   ├── post-service-deployment.yaml
│   ├── frontend-service-deployment.yaml
│   └── api-gateway-deployment.yaml
│
└── README.md               # Project documentation

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How to Run

Step 1: Clone the Repository

git clone https://github.com/subhashpolisetti/blog-microservices-architecture.git
cd blog-microservices-architecture

Step 2: Build Docker Images

# Build User Service
docker build -t user-service ./user-service

# Build Post Service
docker build -t post-service ./post-service

# Build Frontend Service
docker build -t frontend-service ./frontend-service

# Build API Gateway
docker build -t api-gateway ./api-gateway

Step 3: Deploy on Kubernetes

kubectl apply -f user-service/user-service-deployment.yaml
kubectl apply -f post-service/post-service-deployment.yaml
kubectl apply -f frontend-service/frontend-service-deployment.yaml
kubectl apply -f api-gateway/api-gateway-deployment.yaml

Step 4: Access the Application

Access the services through the API Gateway:

• /users/ for user operations
• /posts/ for post operations
• /frontend/ for the frontend interface

Contact

Project Link: https://github.com/subhashpolisetti/blog-microservices-architecture