# Smart Share Hub – Secure Cloud File & Note Sharing Platform

## Overview

Smart Share Hub is a cloud-based web application deployed using Docker containers on a Linux virtual machine. The application allows users to:

- Upload and share files
- Create and share notes
- Access the application publicly through a web browser
- Use HTTPS encryption
- Store persistent data using PostgreSQL and Docker volumes

> Developed for the Cloud Technologies assignment.

---

## Features

### File Upload System
- Upload files through the web interface
- Files stored persistently inside a Docker volume
- Accessible through the browser

### Shared Notes
- Users can create notes
- Notes are stored in a PostgreSQL database
- Notes can be viewed publicly

### HTTPS Support
- Application accessible through HTTPS
- SSL/TLS certificate configured
- Secure encrypted communication

### Docker-Based Deployment
- Fully containerized application
- Easy deployment using Docker Compose
- Repeatable deployment using scripts

### Automatic Restart
- Containers restart automatically after failure
- Uses Docker restart policies

### Backup Support
- Backup script included
- Application data can be archived easily

### Persistent Storage
- PostgreSQL database volume
- Upload storage volume

### Environment Variable Configuration
- Database secrets stored in `.env`
- Sensitive data excluded from Git repository

### Logging
- NGINX access logs available
- Backend logs accessible through Docker

---

## Technologies Used

| Layer | Technology |
|---|---|
| Backend | Python, Flask, psycopg2 |
| Database | PostgreSQL 15 |
| Frontend | HTML, CSS, JavaScript |
| Reverse Proxy | NGINX |
| Containerization | Docker, Docker Compose |

---

## System Architecture

The application consists of four containers:

| Container | Purpose |
|---|---|
| `frontend` | Serves frontend web files |
| `backend` | Flask API server |
| `postgres` | PostgreSQL database |
| `nginx` | Reverse proxy and HTTPS |

---

## Environment Variables

Secrets are stored using environment variables. Create a `.env` file in the project root:

```env
DB_PASSWORD=xxxxxxxx
```

> The `.env` file is excluded from Git using `.gitignore`.

---

## Docker Compose

The main deployment file is `docker-compose.yml`.

```bash
# Start application
docker-compose up -d --build

# Stop application
docker-compose down

# Remove everything including volumes
docker-compose down -v
```

**Database configuration example:**

```yaml
environment:
  POSTGRES_DB: smartshare
  POSTGRES_USER: postgres
  POSTGRES_PASSWORD: ${DB_PASSWORD}
```

---

## Deployment Instructions

### 1. Install Docker

```bash
sudo apt update
sudo apt install docker.io docker-compose -y
```

### 2. Clone Repository

```bash
git clone <repository-url>
cd sk1
```

### 3. Create Environment File

```bash
nano .env
```

Add the following:

```env
DB_PASSWORD=xxxxxxxx
```

### 4. Start Application

```bash
docker-compose up -d --build
```

---

## Public Access

The application is publicly accessible at:

```
https://your-domain
```

Example:

```
https://joblin-share.duckdns.org
```

---

## HTTPS Configuration

HTTPS is configured using:
- NGINX reverse proxy
- SSL/TLS certificates

All traffic is redirected through the secure HTTPS protocol.

---

## Persistent Storage

| Volume | Purpose |
|---|---|
| `postgres_data` | PostgreSQL database storage |
| `uploads` | Uploaded files |

Data remains intact after container restarts.

---

## Automatic Restart Policy

All containers are configured with:

```yaml
restart: always
```

This ensures automatic recovery after crashes or server reboots.

---

## NGINX Reverse Proxy

NGINX handles:
- HTTPS termination
- Reverse proxy routing
- Static frontend delivery
- API request forwarding

| Route | Target |
|---|---|
| `/` | Frontend |
| `/api/` | Backend API |

---

## Security Features

- HTTPS encryption
- Environment-based secret management
- Docker network isolation
- Reverse proxy protection

---

## Backup System

Run the backup script:

```bash
./backup.sh
```

The script:
- Creates compressed backups
- Stores them inside `/backups`
- Can be used for recovery

Example backup file:

```
backup_2026-05-12.tar.gz
```

---

## Scripts

| Script | Description | Usage |
|---|---|---|
| `prepare-app.sh` | Starts the application automatically | `./prepare-app.sh` |
| `remove-app.sh` | Stops and removes all containers | `./remove-app.sh` |
| `backup.sh` | Creates a compressed application backup | `./backup.sh` |

---

## Logs

```bash
# NGINX access logs
docker logs nginx

# Backend application logs
docker logs backend

# PostgreSQL logs
docker logs postgres
```