🚀 DevOps Flask App Deployment using GitHub Actions & EC2

This project demonstrates a complete CI/CD pipeline where a Flask application is automatically deployed to an AWS EC2 instance using GitHub Actions whenever changes are pushed to the main branch.

---

📁 Project Structure

DevOps-Project/
│
├── flask-monitoring-app/        # Flask application
│   ├── app.py                   # Main Flask app
│   └── requirements.txt         # Python dependencies
│
├── .github/workflows/
│   └── deploy.yml               # GitHub Actions CI/CD pipeline
│
├── deploy.sh                    # EC2 deployment script
└── README.md                    # This file

---

⚙️ Tech Stack

• Flask – Python-based web application
• GitHub Actions – CI/CD pipeline
• AWS EC2 (Ubuntu) – Cloud server
• SSH – Secure remote access
• Systemd Service – Persistent app hosting

---

🚀 Deployment Workflow (CI/CD)

✅ Trigger

Whenever code is pushed to the main branch, GitHub Actions triggers the deployment workflow.

✅ GitHub Actions Workflow (.github/workflows/deploy.yml)

name: Deploy Flask App to EC2

on:
  push:
    branches:
      - main

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
    - name: Checkout Code
      uses: actions/checkout@v3

    - name: Setup SSH Key
      run: |
        mkdir -p ~/.ssh
        echo "${{ secrets.EC2_KEY }}" > ~/.ssh/devops_key.pem
        chmod 600 ~/.ssh/devops_key.pem
        ssh-keyscan -H ${{ secrets.EC2_HOST }} >> ~/.ssh/known_hosts

    - name: Deploy to EC2
      run: |
        ssh -i ~/.ssh/devops_key.pem ${{ secrets.EC2_USER }}@${{ secrets.EC2_HOST }} "bash ~/deploy.sh"

---

📜 EC2 Deployment Script (deploy.sh)

#!/bin/bash

cd ~/flask-monitoring-app

# Pull latest changes
git pull origin main

# Activate virtual environment
source ~/env/bin/activate

# Install dependencies
pip install -r requirements.txt

# Restart the Flask systemd service
sudo systemctl restart flask.service

---

🧠 Systemd Service (flask.service)

Located at /etc/systemd/system/flask.service on EC2:

[Unit]
Description=Gunicorn instance to serve Flask App
After=network.target

[Service]
User=ec2-user
Group=www-data
WorkingDirectory=/home/ec2-user/flask-monitoring-app
Environment="PATH=/home/ec2-user/env/bin"
ExecStart=/home/ec2-user/env/bin/gunicorn --workers 3 --bind 0.0.0.0:5001 app:app

[Install]
WantedBy=multi-user.target

Enable and start it:

sudo systemctl daemon-reexec
sudo systemctl daemon-reload
sudo systemctl enable flask
sudo systemctl start flask

---

🔒 GitHub Secrets Required

Go to your repo → Settings → Secrets → Actions and add:

Secret Name	Description
EC2_KEY	Your EC2 private key (PEM file)
EC2_USER	EC2 username (usually ec2-user)
EC2_HOST	EC2 public IP or DNS name

---

🌐 Access the App

Once deployed, access it via:

http://<EC2-PUBLIC-IP>:5001

Make sure port 5001 is open in your EC2 Security Group (inbound rule).

🏁 Final Result

✅ CI/CD working via GitHub Actions ✅ Flask app auto-deploys to EC2 ✅ Visible live on: http://<your-ec2-ip>:5001

---