Microservices POC Project

This project is a proof-of-concept (POC) microservices architecture built with Go (Golang), using multiple services to manage courses, students, and enrollments. It includes a GraphQL gateway for API aggregation and service communication via REST APIs.

📌 Project Structure

├── course/          # Course service (manages courses)
├── student/         # Student service (manages students)
├── enrollment/      # Enrollment service (handles student enrollments in courses)
├── gateway/         # GraphQL API Gateway (aggregates data from other services)
├── docker-compose.yaml  # Docker Compose file for running services
├── .gitignore       # Git ignore file

🏗️ Microservices Overview

1️⃣ Course Service (course/)

• Provides CRUD operations for managing courses.
• Exposes REST API endpoints.
• Runs on port 8082.

2️⃣ Student Service (student/)

• Manages student registrations.
• Exposes REST API endpoints.
• Runs on port 8081.

3️⃣ Enrollment Service (enrollment/)

• Manages student enrollments in courses.
• Verifies student and course existence before enrollment.
• Runs on port 8083.

4️⃣ API Gateway (gateway/)

• Provides a GraphQL API to unify data access.
• Fetches data from course, student, and enrollment services.
• Runs on port 8080.

🚀 Getting Started

1️⃣ Clone the Repository

 git clone https://github.com/Latte-Corporation/POC-GraphQL.git
 cd POC-GraphQL

2️⃣ Run with Docker Compose

 docker-compose up --build

This will start all services and expose the GraphQL API at http://localhost:8080.

3️⃣ Testing the APIs

• GraphQL Playground: http://localhost:8080/
• Course API: GET http://localhost:8082/api/courses
• Student API: GET http://localhost:8081/api/students
• Enrollment API: GET http://localhost:8083/api/enrollments

🛠️ Technologies Used

• Go (Golang) - Language for all microservices
• Echo - Web framework for REST APIs
• GraphQL (GQLGen) - API Gateway for data aggregation
• Docker & Docker Compose - Containerization and orchestration
• Distroless Base Image - Minimal container image for security

📜 API Endpoints

Course Service (/course)

Method	Endpoint	Description
GET	/api/courses	Get all courses
GET	/api/courses/:id	Get course by ID
POST	/api/courses	Create a new course

Student Service (/student)

Method	Endpoint	Description
GET	/api/students	Get all students
GET	/api/students/:id	Get student by ID
POST	/api/students	Create a new student

Enrollment Service (/enrollment)

Method	Endpoint	Description
GET	/api/enrollments	Get all enrollments
GET	/api/enrollments/:id	Get enrollment by ID
POST	/api/enrollments	Enroll a student in a course

⚡ GraphQL Queries & Mutations

Get all Students and Courses

query {
	students {
		id
		name
		courses {
			title
		}
	}
	courses {
		id
		title
	}
}

Enroll a Student in a Course

mutation {
	enrollStudentInCourse(studentId: "1", courseId: "2") {
		title
		students {
			name
		}
	}
}

🛠️ Development & Contribution

1. Clone the repo and create a feature branch.
2. Modify the required service (course, student, enrollment, gateway).
3. Run go mod tidy to ensure dependencies are correct.
4. Test locally with docker-compose up --build.
5. Create a Pull Request for review.

🏁 Conclusion

This POC showcases a scalable microservices architecture using Go, GraphQL, and Docker. It can be extended with a database layer, authentication, and caching for production usage.