User Management System with PostgreSQL, Redis, Kafka, and Prometheus

This Go-based web application provides a user management system with the following features:

• CRUD operations for users
• Caching with Redis
• Event streaming and reading with Kafka
• Monitoring with Prometheus

Features

Technologies Used:

• Go (Golang)
• PostgreSQL for database
• Redis for caching
• Kafka for streaming events
• Prometheus for monitoring
• Gorilla Mux for routing

API Endpoints

Endpoint	Method	Description
/users	POST	Create a new user
/users/:id	GET	Get a user by ID
/users/:id	PUT	Update user by ID
/users/:id	DELETE	Delete user by ID
/users/{id}/status	PUT	Mark a user as inactive
/users	GET	Fetch all users
/metrics	GET	Prometheus metrics
/metric	GET	Show hit counters (custom)

Getting Started

Prerequisites

• Go installed
• PostgreSQL server running
• Redis server running
• Kafka broker running

Setup

1. Clone the repository

   git clone https://github.com/niku-raaz/UserManagementSystem
   cd UserManagement

2. Update PostgreSQL connection string In producer.go, update the following line with your credentials:

   conStr := "postgres://YOURUSERNAME:YOURPASSWORD@localhost:5432/USERDB?sslmode=disable"

3. Run Kafka locally Make sure Kafka is running at localhost:9092.

4. Run Redis Ensure Redis is running at localhost:6379.

5. Run the application

   go run producer.go

Kafka Usage

The app produces user creation events to Kafka under the topic user-events.

Redis Usage

• Users are cached in Redis after retrieval from the database.
• On update/delete, the corresponding Redis entry is invalidated.

Prometheus Monitoring

• The app exposes metrics at /metrics

• Tracks:

  • Number of API hits (api_hits_total)
  • Latency of each API call (api_latency_seconds)
  • Number of server errors (api_errors_total)

Author

• Built by Niku Raj as part of a full-stack distributed systems project.