Payroll Microservice System

A comprehensive microservice architecture for enterprise payroll management built with Go, featuring distributed tracing, role-based access control, and audit logging.

System Architecture

This system implements a modern microservices architecture with the following components:

• API Gateway: Single entry point that routes requests to appropriate services
• Service Mesh: Inter-service communication with context propagation
• Distributed Tracing: End-to-end request tracking with OpenTelemetry and Jaeger
• Role-Based Access Control: Admin and Employee permission levels
• Audit Logging: Comprehensive activity tracking across all services
• Database Per Service: Each microservice manages its own data store

Services

Core Services

• Gateway Service (Gin): Routes requests to appropriate microservices, handles request tracing, and forwards authentication headers
• Auth Service: Manages authentication, JWT token generation, and validation
• User Service: Handles user management and profile information

Business Logic Services

• Payroll Service (Chi): Manages pay periods, and coordinates with other services during payroll runs
• Overtime Service (Chi): Calculates overtime hours based on attendance data
• Attendance Service (Chi): Tracks employee clock-in/clock-out times and validates attendance records
• Reimbursement Service (Chi): Processes expense reimbursement requests

Distributed Tracing & Monitoring

The system implements OpenTelemetry for distributed tracing with:

• Jaeger for trace visualization
• OTel Collector for telemetry data processing
• Context propagation across service boundaries
• Span correlation for end-to-end request tracking

Role-Based Access Control

Two primary roles are supported:

• Admin: Full system access with management capabilities
• Employee: Limited access to personal records and submissions

Inter-Service Communication

• HTTP-based service communication with context propagation
• Shared client package for standardized service calls
• Header propagation for maintaining trace context and user information

Audit Logging

• Comprehensive audit trail for all data modifications
• Records user ID, IP address, request ID, and trace ID
• Stores before/after state for all changes

Setup Instructions

Prerequisites

• Go 1.18 or higher
• PostgreSQL 13 or higher
• Jaeger and OTel Collector for tracing (optional but recommended)

Environment Setup

For detailed setup and running instructions, see the RUN.md file.