Library API Microservices

Note

After adding a new user, you must create a bearer token (/login) and set it in the header of every request to other microservices

This project implements a microservices architecture for managing a library system. The system consists of several services, each responsible for its specific functionality.

Stack

Launch Order

No.	Service Name	Environment Variables	Database
1	Discovery Server
2	Authentication Server	jwt.secret.key, jwt.expiration.access, jwt.expiration.refresh	library_auth_db
3	User Service	jwt.secret.key	library_users_db
4	Books Service	jwt.secret.key	library_books_db
5	Loan Service	jwt.secret.key	library_loans_db
6	Library Service	jwt.secret.key	library_db
7	API Gateway	jwt.secret.key

Note

Make sure to pass the environment variables in the "Modify Run Configuration" menu under the "Environment Variables" section.

Services

1. User Service

The user management service is responsible for storing and managing user accounts.

• Main features:

  • Managing user registration and details.

• Endpoints:
  POST /api/users

  {
    "name": "Alexander Dudkin",
    "username": "thisdudkin",
    "email": "alexraddan@gmail.com",
    "password": "password"
  }
  

  GET /api/users/{username}

  PUT /api/users/{username}

  {
    "name": "Ivan Prokopenya",
    "username": "ongotaj",
    "email": "ivan123@gmail.com",
    "password": "password"
  }
  

  DELETE /api/users/{id}

2. Authentication Server

The authentication service is responsible for issuing JWT tokens for users in the system.

• Main features:

  • User authentication.
  • Issuing access and refresh tokens.
  • Token renewal.

• Endpoints:

  POST /api/auth/login

  {
    "username": "thisdudkin",
    "password": "password"
  }
  

  POST /api/auth/refresh?refreshToken=

3. Books Service

The book management service handles operations related to books, including creation, updating, deletion, and retrieving information about books.

• Main features:

  • Managing book data.
  • Searching for books.

• Endpoints:
  POST /api/books

  {
    "isbn": "9785171624927",
    "title": "Евгений Онегин",
    "genre": "Роман",
    "description": "Пронзительная любовная история, драматические повороты сюжета, тонкий психологизм персонажей, детальное описание быта и нравов той эпохи (не случайно Белинский назвал роман \"энциклопедией русской жизни\") – в этом произведении, как в зеркале, отразилась вся русская жизнь. \"Евгений Онегин\" никогда не утратит своей актуальности, и даже спустя два века мы поражаемся точности и верности \"ума холодных наблюдений и сердца горестных замет\" великого русского поэта.",
    "author": "Александр Пушкин"
  }
  

  GET /api/books/{bookId}

  GET /api/books/isbn/{isbn}

  PUT /api/books/{bookId}

  {
    "isbn": "978-5-00132-211-5",
    "title": "Сказка о рыбаке и рыбке",
    "genre": "Сказка",
    "description": "Уже в дошкольном возрасте стоит прочитать малышам сказки великого поэта, познакомить их с чудесным миром, который он создал в своих произведениях и без которого мы уже не мыслим свою жизнь, своё духовное развитие.",
    "author": "Александр Пушкин"
  }
  

  DELETE /api/books/{bookId}

4. Discovery Server

The discovery server (Eureka) allows other services to register and discover each other dynamically within the microservices environment.

• Main features:
  • Service registration and discovery.

5. API Gateway

The API Gateway acts as the entry point to the system, routing requests to the appropriate services.

• Main features:

  • Request routing.
  • Centralized authentication and authorization.

• Endpoints:
  any request on port :8080

6. Loan Service

The loan service manages book loan information, including tracking due dates and book returns.

• Main features:

  • Tracking loaned books.
  • Managing return deadlines.

• Endpoints:
  POST /api/loans

  {
    "bookId": 1
  }
  

  GET /api/loans/{loanId}

  PUT /api/loans/{bookId}

7. Library Service

The library management service stores information about available books in the library, including which book is free and which is on loan.

• Main features:

  • Store information about books in library

• Endpoints: (for internal requests!!!)
  POST /api/library

  GET /api/library/{bookId}

  PUT /api/library/{bookId}

  DELETE /api/library/{bookId}

Architecture

The project uses a microservices architecture where each service is independent and communicates with others via REST APIs (OpenFeign client). Eureka Discovery Server is used for service registration and discovery, and Spring Cloud Gateway routes requests between services.

Main components:

• Spring Boot - for building each microservice.
• Eureka - for service registration and discovery.
• Spring Cloud Gateway - for request routing through the API gateway.
• Feign - for simplifying REST API calls to other microservices.
• Spring Security - for authentication and authorization.

Requirements

• Java 21 or higher.
• Maven 3.8.7+ for building the project.

Running the Project

1. Clone the repository:

   git clone https://github.com/earlspilner/library-api.git

2. Navigate to the project's root directory:

   cd library-api

3. Build all services:

   mvn clean install

4. Start each service, beginning with Discovery Server:

   cd library-api-discovery-server
   mvn spring-boot:run

Repeat the process for each service in the required order.

Environment Variables

Variable Name	Description	Default Value
jwt.secret.key	JWT secret key, generated via KeyGen.java	(Generate it)
jwt.expiration.access	Access token expiration time (in ms)	300000 (5 minutes)
jwt.expiration.refresh	Refresh token expiration time (in ms)	3600000 (1 hour)

Authentication and Authorization

The system uses JWT tokens for authentication and authorization. After successful login via library-api-authentication-server, the client receives access and refresh tokens, which should be included in the Authorization header when making requests to other services.