Cold Storage Management System

Web-based management system for cold storage facilities with role-based access, inventory tracking, payment processing, and multi-language support.

Version: 1.5.53 Last Updated: December 24, 2025

Features

• Multi-Language Support: English and Hindi (i18n)
• Role-Based Access Control: Admin, Employee, Accountant roles
• Inventory Management: Track items across rooms and gatars
• Gate Pass System: Issue, approve, and track item withdrawals
• Payment Processing: Rent calculations and payment tracking
• Offline Mode: Works on local network without internet
• Customer Portal: Self-service for customers to request gate passes
• Auto-Recovery: Automatic database fallback and setup wizard for disaster recovery
• Cloud Backup: Cloudflare R2 integration for offsite backups

Tech Stack

• Backend: Go 1.23, Gorilla Mux, pgx/v5
• Frontend: HTML5, Tailwind CSS, Vanilla JS, Bootstrap Icons
• Database: PostgreSQL 17 (CloudNative-PG)
• Infrastructure: K3s, Longhorn, MetalLB
• Monitoring: Node Exporter, Custom metrics

Project Structure

cold-backend/
├── cmd/server/          # Application entry point
├── configs/             # Configuration files
├── docs/                # Documentation
├── internal/
│   ├── handlers/        # HTTP request handlers
│   ├── http/            # Router and middleware
│   ├── models/          # Data models
│   ├── repositories/    # Database operations
│   └── services/        # Business logic
├── k8s/                 # Kubernetes manifests
├── migrations/          # SQL migrations
├── scripts/             # Deployment and utility scripts
├── static/              # Static assets (CSS, JS, fonts)
│   ├── css/             # Tailwind, Bootstrap Icons
│   ├── fonts/           # Web fonts
│   ├── js/              # JavaScript (i18n)
│   └── locales/         # Translation files (en.json, hi.json)
└── templates/           # HTML templates

Quick Start

# Install dependencies
go mod download

# Start PostgreSQL
docker run --name cold-postgres -e POSTGRES_PASSWORD=postgres -e POSTGRES_DB=cold_db -p 5432:5432 -d postgres:17

# Run migrations
for f in migrations/*.sql; do docker exec -i cold-postgres psql -U postgres -d cold_db < "$f"; done

# Build & run
go build -o server ./cmd/server/
./server

Access at http://localhost:8080

User Roles

Role	Access
Employee	Create entries, room assignments, gate pass entry
Accountant	Payment processing, rent management
Admin	Full access + user management, reports, system settings

Default Login

• Email: [email protected]
• Password: admin123

Storage Layout

The facility has 5 storage areas:

Room	Type	Gatars	Status
Room 1	Seed	1-680	Active
Room 2	Seed	681-1360	Active
Room 3	Sell	1361-2040	Active
Room 4	Sell	TBD	Pending
Gallery	Sell	TBD	Pending

Each room has 5 floors (0-4) with gatar ranges defined per floor.

API Endpoints

Authentication

Method	Endpoint	Description
POST	/auth/login	User login
GET	/logout	User logout

Core APIs

Method	Endpoint	Description
GET	/api/entries	List entries
POST	/api/entries	Create entry
GET	/api/room-entries	List room entries
POST	/api/room-entries	Create room entry
PUT	/api/room-entries/:id	Update room entry
POST	/api/rent-payments	Create payment
GET	/api/gate-passes	List gate passes
POST	/api/gate-passes	Create gate pass

Admin APIs

Method	Endpoint	Description
GET	/api/users	List users
POST	/api/users	Create user
GET	/api/customers	List customers

Multi-Language Support

The application supports English and Hindi. Translation files are located in:

• static/locales/en.json - English translations
• static/locales/hi.json - Hindi translations

Users can switch languages using the dropdown in the header. The selected language is persisted in localStorage.

Production Deployment

# Build Docker image
docker build -t cold-backend:v1.4.75 .

# Deploy to K3s
kubectl apply -f k8s/

# Or use deployment script
./scripts/deploy/deploy.sh v1.4.75

Production URL: http://192.168.15.200:8080

K3s Cluster

Node	IP	Role
k3s-master	192.168.15.110	Control Plane
k3s-worker-1	192.168.15.111	Worker
k3s-worker-2	192.168.15.112	Worker
k3s-worker-3	192.168.15.113	Worker
k3s-worker-4	192.168.15.114	Worker

VIP: 192.168.15.200 (MetalLB)

Documentation

See docs/ folder for detailed documentation:

• API Documentation - Complete API reference
• Database Schema - Database design
• K3s Infrastructure - Cluster setup
• Room Layout - Gatar mapping
• Documentation Index - Full index

Environment Variables

# Database
DB_HOST=localhost
DB_PORT=5432
DB_USER=postgres
DB_PASSWORD=postgres
DB_NAME=cold_db

# Server
PORT=8080
JWT_SECRET=your-secret-key

Disaster Recovery

The application includes built-in disaster recovery features:

Automatic Database Fallback

When the app starts, it tries to connect to databases in order:

1. K8s Cluster (Primary): 192.168.15.200:5432
2. Backup Server: 192.168.15.195:5434

If both fail, the app enters Setup Mode.

Setup Mode

When no database is available, the app shows a setup wizard:

• Configure database connection manually
• Restore from Cloudflare R2 backup

Access the setup screen at http://localhost:8080/setup

Recovery Package

A standalone recovery package is available at /home/lakshya/backups/cold-backend/:

• server - Linux binary (31 MB)
• templates/ - HTML templates
• static/ - CSS, JS, fonts
• RECOVERY.md - Step-by-step recovery guide

Quick Recovery

# 1. Extract recovery package
tar xzf cold-backend.tar.gz
cd cold-backend

# 2. Configure database (or use setup wizard)
cat > .env << 'EOF'
DB_HOST=192.168.15.195
DB_PORT=5434
DB_USER=postgres
DB_PASSWORD=postgres
DB_NAME=cold_db
JWT_SECRET=cold-backend-jwt-secret-2025
EOF

# 3. Run
./server

License

Proprietary - All rights reserved.