🔐 Authentication & Authorization

Microservices Architecture with Separate Auth Flow
👥 Client Layer

💻 Client Application

Web / Mobile / Desktop

↓
🚪 API Gateway Layer

🔀 API Gateway

Node.js Express
JWT Verification & Routing
Rate Limiting

Gateway routes to Auth Service (one-time login) OR Business Services (with valid JWT)
🔐 Authentication Flow (One-Time)
📤 Request
↓
POST /login
username + password
📥 Response
↑
JWT Token
User Info
🔑 Auth Service

🔑 Authentication

Validate Credentials
MD5 Hash Check
Generate JWT Token
Set Expiry

📤 Request
↓
SELECT * FROM admin
WHERE username
📥 Response
↑
User Record
password, role
🗄️ Admin Database

🗄️ MySQL

Admin Table
• username
• password (MD5)
• role
• permissions

⚙️ Business Logic Flow (Every Request)
📤 Request
↓
GET/POST/PUT/DELETE
Headers: Bearer JWT
📥 Response
↑
JSON Data
Status Code
⚙️ Services Layer

⚡ Node.js

Express
REST APIs

☕ Java

Spring Boot
Microservices

🐍 Python

Flask
Data APIs

📤 Request
↓
SQL / NoSQL Query
INSERT / UPDATE / SELECT
📥 Response
↑
Query Results
Affected Rows
💾 Data Layer

🗄️ MySQL

Relational
Transactional

🍃 MongoDB

NoSQL
Documents

🔍 Elasticsearch

Search
Analytics

⚡ Redis

Cache
Session