Warehouse Management System

A role-based inventory management web application built with Go (Gin), MongoDB, and vanilla HTML/CSS/JS — featuring JWT authentication, rate limiting, a separate payment microservice, and PDF receipt generation.

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Overview

Built as a university group project at Astana IT University (SE-2311) by Adil Ormanov and Madi Kassymov.

The system lets different user roles manage a product inventory backed by MongoDB. A lightweight second service (transaction-service) handles the payment flow separately: the main backend creates a pending transaction and redirects the user to the payment form; the transaction service validates the card, updates the status, generates a PDF receipt, and emails it to the buyer.

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Features

• Role-based access control — three roles enforced by JWT middleware:
  • admin — full CRUD on products and users, manage roles
  • cashier — manage product quantities (assumed via the role system)
  • unregistered / guest — read-only product listing
• User management — register, email verification, login, profile CRUD, admin-controlled role updates
• Product catalog — full CRUD with rich attributes: type, brand, model, processor, RAM, storage, color, price, quantity, warranty; paginated and filterable listing (type, price range, brand, RAM, storage, processor, color) with sort support
• Shopping cart — add, remove, clear, and pay via cart; cart items persisted in MongoDB
• Payment microservice — create pending transaction, show payment form, validate card details (number format, CVV regex, expiry MM/YY), simulate approval (cards starting with 4 succeed), update status to paid or declined
• PDF receipt generation — on successful payment, generates a PDF receipt (gofpdf) and emails it to the buyer via SMTP (gomail)
• Rate limiting — /api/contact endpoint limited to 1 request per 15 seconds using golang.org/x/time/rate
• Contact form — email sending via SMTP with rate protection
• Structured logging — Logrus with log rotation (lumberjack), request logging middleware
• CORS — configurable allowed origins

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Tech Stack

Layer	Technologies
Language	Go 1.23
HTTP framework	Gin
Database	MongoDB (go.mongodb.org/mongo-driver)
Auth	JWT HS256 (golang-jwt/jwt/v5)
PDF generation	jung-kurt/gofpdf
Email	gopkg.in/gomail.v2
Rate limiting	golang.org/x/time/rate
Logging	Logrus + lumberjack
Frontend	HTML, CSS, JavaScript (no build step)
Containers	Docker, Docker Compose

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Project Structure

Warehouse_Management_System/
├── warehouse-backend/
│   ├── main.go                      # Entry point: router setup, graceful shutdown
│   ├── config/config.go             # Config loading
│   ├── models/
│   │   ├── user.go                  # User schema (id, name, email, role, verified)
│   │   ├── product.go               # Product schema (type, brand, model, specs, price, qty)
│   │   └── cart.go                  # Cart schema
│   ├── controllers/
│   │   ├── auth_controller.go       # Register, login, email verification
│   │   ├── profile_controller.go    # Get/update profile
│   │   ├── user_controller.go       # Admin user management
│   │   ├── shoppingCart_controller.go # Cart operations + pay
│   │   └── contact_controller.go    # Contact form + email
│   ├── middleware/
│   │   ├── auth.go                  # JWT generation, validation, AuthMiddleware
│   │   └── rate_limit_middleware.go # Token bucket rate limiter
│   ├── routes/
│   │   ├── auth_routes.go
│   │   └── product_routes.go
│   ├── database/
│   │   ├── database.go              # Product CRUD with filtering + pagination
│   │   ├── mongo_connection.go      # MongoDB connect/disconnect
│   │   └── cart.go                  # Cart DB operations
│   └── logger/logger.go             # Logrus setup with lumberjack rotation
├── transaction-service/
│   └── main.go                      # Payment microservice (Gin :8081)
│                                    # Endpoints: POST /transactions,
│                                    #   GET  /transactions/:id/payment,
│                                    #   POST /transactions/:id/pay
│                                    # PDF receipt + email on successful payment
└── warehouse-frontend/
    ├── index.html                   # Product listing (guest access)
    ├── admin.html                   # Admin dashboard
    ├── LogIn.html / SignUp.html
    ├── profile.html
    ├── shoppingСart.html
    ├── ContactUs.html
    ├── js/                          # auth.js, index.js, admin.js, shoppingCart.js, etc.
    └── css/                         # Per-page stylesheets

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Getting Started

Prerequisites

• Go 1.23+
• MongoDB (local or Atlas)
• Docker + Docker Compose (optional)
• SMTP credentials for email features

Environment variables

Create a .env file in warehouse-backend/ with:

MONGO_URI=mongodb://localhost:27017
MONGO_DB=warehouse
JWT_SECRET=<your-secret>
CORS_ORIGINS=http://localhost:3000,http://localhost:8080
SMTP_HOST=smtp.gmail.com
SMTP_PORT=587
SMTP_EMAIL=<your-email>
SMTP_PASSWORD=<app-password>

Create a .env in transaction-service/ with:

MONGO_URI=mongodb://localhost:27017
MONGO_DB=warehouse
PORT=8081
SMTP_HOST=smtp.gmail.com
SMTP_PORT=587
SMTP_EMAIL=<your-email>
SMTP_PASSWORD=<app-password>

Run the backend

cd warehouse-backend
go mod tidy
go run main.go
# Server starts on :8080

Run the transaction service

cd transaction-service
go mod tidy
go run main.go
# Service starts on :8081

Run with Docker Compose

cd warehouse-backend
docker compose up --build

Open the frontend

Open warehouse-frontend/index.html directly in a browser, or serve it with any static file server.

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API Endpoints

Auth

Method	Path	Auth	Description
POST	/auth/register	—	Register new user
POST	/auth/login	—	Login, receive JWT
GET	/auth/verify	—	Verify email token

Products

Method	Path	Auth	Description
GET	/products/	—	List products (paginated, filterable)
GET	/products/:id	—	Get product by ID
POST	/products/create	admin	Create product
PUT	/products/:id	admin	Update product
DELETE	/products/:id	admin	Delete product
DELETE	/products/deleteAll	admin	Delete all products

Users (admin only)

Method	Path	Description
GET	/users/	List all users
GET	/users/:id	Get user by ID
PUT	/users/:id	Update user
PUT	/users/:id/role	Change user role
DELETE	/users/:id	Delete user

Profile & Cart

Method	Path	Description
GET	/protected/profile	Get current user profile
PUT	/protected/profile	Update profile
POST	/cart/:product_id/add	Add item to cart
GET	/cart/	View cart
DELETE	/cart/:product_id/remove	Remove item
DELETE	/cart/clear	Clear cart
POST	/cart/pay	Checkout (creates transaction)

Transaction service (:8081)

Method	Path	Description
POST	/transactions	Create pending transaction
GET	/transactions/:id/payment	Show payment form
POST	/transactions/:id/pay	Submit payment (validates card, generates PDF receipt)

Other

Method	Path	Description
POST	/api/contact	Contact form (rate-limited: 1 req / 15 s)

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Screenshot

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Adil Ormanov — GitHub