User Service Documentation

This document provides a comprehensive guide to setting up and using the User Service. Follow these steps to get the service running and understand its key components.

Table of Contents

1. Overview
2. Features
3. Prerequisites
4. Setup Instructions
   • Using Docker Compose
   • Environment Variables
5. Key Components
6. Dependencies
7. Future Enhancements

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Overview

The User Service is a backend service designed for managing users. It supports operations such as creating, updating, retrieving, and deleting user records.

Caching: Redis is used to cache verified tokens and frequently accessed user data, improving performance.

Token Validation: Token validation requires a separate Authentication Service. The User Service will not work correctly without the Authentication Service being set up.

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Features

• User CRUD operations
• Redis caching for performance optimization
• Health check endpoint to monitor service status
• JWT Middleware for secure access
• Dependency injection for modular and testable code

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Prerequisites

1. Docker and Docker Compose installed on your system.
2. PostgreSQL and Redis configured via Docker Compose.
3. An Authentication Service for token validation.

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Setup Instructions

Using Docker Compose

The service relies on PostgreSQL and Redis. Use the provided docker-compose.yml file to set up the required containers.

1. Download or create the docker-compose.yml file with the following content:

   services:
     postgres:
       image: postgres:latest
       container_name: postgres_container_users_v2
       environment:
         POSTGRES_USER: test
         POSTGRES_PASSWORD: 1234
         POSTGRES_DB: users
       ports:
         - "5433:5432"
       volumes:
         - postgres_data:/var/lib/postgresql/data
       networks:
         - mynetwork
   
     pgadmin:
       image: dpage/pgadmin4
       container_name: pgadmin_container_users_v2
       environment:
         PGADMIN_DEFAULT_EMAIL: [email protected]
         PGADMIN_DEFAULT_PASSWORD: admin
       ports:
         - "5051:80"
       depends_on:
         - postgres
       networks:
         - mynetwork
   
     redis:
       image: redis:latest
       container_name: redis_container_users_v2
       ports:
         - "6379:6379"
       networks:
         - mynetwork
   
   volumes:
     postgres_data:
   
   networks:
     mynetwork:
       driver: bridge

2. Start the services:

   docker-compose up -d

3. Verify that the PostgreSQL, PgAdmin, and Redis containers are running.

Environment Variables

Configure the service using the .env file. Below is the required configuration:

DB_DSN=host=localhost user=test password=1234 dbname=users port=5433 sslmode=disable TimeZone=Asia/Colombo

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Key Components

Router

The SetUpRouter function initializes the Gin router and sets up routes, middleware, and controllers. It connects to both PostgreSQL and Redis.

Example routes:

• Health Check: GET /
• User Operations:
  • GET /v1/users - Get all users
  • GET /v1/user/:id - Get user by ID
  • POST /v1/users - Create a new user
  • PUT /v1/update - Update a user
  • DELETE /v1/delete/:id - Delete a user

Caching with Redis

• Used to cache verified tokens and user results.
• Improves the performance of frequent operations.

Token Validation

• Requires a separate Authentication Service.
• Without the Authentication Service, token validation will fail.

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Dependencies

• Gin Framework: For building HTTP web services.
• Redis: For caching.
• PostgreSQL: Primary database.
• Docker Compose: For managing dependencies and infrastructure.

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Future Enhancements

• Addition of more endpoints for advanced user management.
• Improved role-based access control.
• Enhanced logging and monitoring.

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Running the Application

Once the database and caching layers are up, start the User Service:

go run main.go

Access the health check endpoint to verify the service is running:

curl http://localhost:8080/

Expected response:

{
  "status": "Service is up and running"
}