Messaging System with RabbitMQ/Celery and Python Application behind Nginx

Introduction

This project aims to deploy a Python application behind Nginx that interacts with RabbitMQ/Celery for email sending and logging functionality. The application is a Flask-based web application that sends emails asynchronously using Celery and logs messages to a file. The application also uses Nginx as a reverse proxy and Ngrok for exposing the local server to the internet.

RabbitMQ is a message broker that enables applications to communicate with each other by sending and receiving messages.
Celery is a distributed task queue that allows you to run tasks asynchronously.
Nginx is a web server that can also be used as a reverse proxy, load balancer, and HTTP cache.

Introduction
Getting Started
Usage
Configuration
Contributing
License

Getting Started

Prerequisites

Local Setup:
- Install RabbitMQ and Celery on your local machine.
- Set up a Python application with the following functionalities:
  - An endpoint that can accept two parameters: ?sendmail and ?talktome.
Endpoint Functionalities:
- ?sendmail: When this parameter is passed, the system should:
  - Send an email using SMTP to the value provided (e.g., ?sendmail=destiny@destinedcodes.com).
  - Use RabbitMQ/Celery to queue the email sending task.
  - Ensure the email-sending script retrieves and executes tasks from the queue.
- ?talktome: When this parameter is passed, the system should:
  - Log the current time to /var/log/messaging_system.log.
Nginx Configuration:
- Configure Nginx to serve your Python application.
- Ensure proper routing of requests to the application.
Endpoint Access:
- Use Ngrok or a similar tool to expose your local application endpoint for external access.
- Provide a stable endpoint for testing purposes.
Documentation and Walk-through:
- Record a screen-captured walk-through of the entire setup and deployment process.
- Ensure the video covers:
  - RabbitMQ/Celery setup.
  - Python application development.
  - Nginx configuration.
  - Sending email via SMTP.
  - Logging current time.
  - Exposing the endpoint using Ngrok.
- Submit the endpoint and screen recording.

Features

Asynchronous email sending using Celery and RabbitMQ.
Logging system that writes to a log file with elevated permissions.
Nginx configuration for serving the Flask application.
Ngrok integration for exposing the local server to the internet.
SSL setup for secure communication.

Prerequisites

RabbitMQ and Celery

Install RabbitMQ and Celery on your local machine.

Python Application

Set up a Python application with the following functionalities:
- An endpoint that can accept two parameters: ?sendmail and ?talktome.

Nginx

Configure Nginx to serve your Python application.

Ngrok

Use Ngrok or a similar tool to expose your local application endpoint for external access.

Below are all the dependencies to be put in `requirements.txt` so as to be installed altogether:

Python 3.10
Flask
Flask-Mail
Celery
RabbitMQ
Redis
Nginx
Ngrok
OpenSSL

Installation

Install RabbitMQ, start RabbitMQ, and check status

sudo apt-get update
sudo apt-get install rabbitmq-server
sudo systemctl enable rabbitmq-server
sudo systemctl start rabbitmq-server
sudo systemctl status rabbitmq-server

Install Nginx:
sudo apt-get install nginx
Install NGROK:

curl -s https://ngrok-agent.s3.amazonaws.com/ngrok.asc | \
sudo gpg --dearmor -o /etc/apt/keyrings/ngrok.gpg && \
echo "deb [signed-by=/etc/apt/keyrings/ngrok.gpg] https://ngrok-agent.s3.amazonaws.com buster main" | \
sudo tee /etc/apt/sources.list.d/ngrok.list && \
sudo apt update && sudo apt install ngrok

Usage

Clone the repository:

git clone https://github.com/yourusername/Messaging-System.git
cd Messaging-System

Create a virtual environment and activate it:

python3 -m venv .venv
source .venv/bin/activate

Install the dependencies:
```
pip install -r requirements.txt
```

Create a .env file for environment variables:

    SMTP_MAIL_SERVER=smtp.your-email-provider.com
    SMTP_MAIL_PORT=587
    SMTP_MAIL_USERNAME=your-email@example.com
    SMTP_MAIL_PASSWORD=your-email-password
    SMTP_MAIL_USE_TLS=True
    SMTP_MAIL_USE_SSL=False
    RABBITMQ_ADDRESS=pyamqp://guest@localhost//
    REDIS_ADDRESS=redis://localhost:6379/0

Configuration

Generate SSL certificates:

    openssl genrsa -out localhost.key 2048
    openssl req -new -key localhost.key -out localhost.csr
    openssl x509 -req -days 365 -in localhost.csr -signkey localhost.key -out localhost.crt

Configure Nginx:

Create configuration file for flask application:

sudo nano /etc/nginx/sites-available/messaging_system

Use the following configuration:

server {
    listen 80;
    listen 443 ssl;

    server_name localhost;

    ssl_certificate /path/to/localhost.crt;
    ssl_certificate_key /path/to/localhost.key;

    location / {
        proxy_pass http://127.0.0.1:5000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }

    location /log {
        alias /var/log/messaging_system.log;
        default_type text/plain;
        add_header Content-Type text/plain;
    }
}

Enable the Configuration:

sudo ln -s /etc/nginx/sites-available/messaging_system /etc/nginx/sites-enabled

Test the configuration:

sudo nginx -t

Restart Nginx:

sudo systemctl restart nginx

Starting the application

Run the Celery worker:

celery -A app.celery worker --loglevel=info

Run the Flask application:
```
python app.py
```
Expose the application using Ngrok:
```
ngrok http 80 --host-header=localhost
```

Visit http://localhost to access the application.
Use http://localhost?sendmail=recipient@example.com to queue an email.
Use http://localhost?talktome to log the current time.
Use http://localhost/log to see logs.

Logging

Logs are written to /var/log/messaging_system.log. Ensure your user has the necessary permissions to write to this file.

Run the following commands to set the appropriate permissions:

    sudo touch /var/log/messaging_system.log
    sudo chown yourusername:yourusername /var/log/messaging_system.log
    sudo chmod 664 /var/log/messaging_system.log
    sudo usermod -a -G yourusername $USER
```

To get your username
```sh
- whoami
- $USER
```
Troubleshooting:

- If you encounter permission errors, ensure that the log file has the correct ownership and permissions.
- Check the Nginx error logs for any issues related to logging.

## Contributing
Guidelines for contributing to the project.

1. Fork the repository
2. Create a new branch (git checkout -b feature-branch)
3. Commit your changes (git commit -m 'Add some feature')
4. Push to the branch (git push origin feature-branch)
5. Open a Pull Request

**Coding Standards**:
- Follow PEP 8 for Python code.
- Write clear and concise commit messages.
- Include comments and documentation for your code.

**Guidelines**:
- Ensure your code passes all tests before submitting a pull request.
- Provide a detailed description of your changes in the pull request.

## License
This project is licensed under the GNU GENERAL PUBLIC LICENSE - see the LICENSE file for details.

**Summary**:
The GNU General Public License is a free, copyleft license for software and other kinds of works. It guarantees end users the freedom to run, study, share, and modify the software.

Stevecmd/Messaging-System

Messaging System with RabbitMQ/Celery and Python Application behind Nginx

Introduction

Table of Contents

Getting Started

Prerequisites

Features

Prerequisites

RabbitMQ and Celery

Python Application

Nginx

Ngrok

Installation

Usage

Configuration

Starting the application

Logging