#14 Develop and Deploy Flask

Flask: Build & Deploy Fast

This guide walks you through developing a simple Flask app and deploying it to production using Git and a web dashboard such as Render or Heroku.

Step 1: Set Up Your Flask App Locally

1. Install Flask:

   pip install flask

2. Create app.py:

   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route('/')
   def hello():
       return "Hello, Flask World!"
   
   if __name__ == '__main__':
       app.run(debug=True)
   

3. Test your app locally:

   python app.py

   Open http://127.0.0.1:5000/ in your browser. You should see “Hello, Flask World!”

Step 2: Prepare for Deployment

1. Create a requirements.txt file:

   pip freeze > requirements.txt

2. Add a Procfile (for platforms like Heroku or Render):

   web: gunicorn app:app

3. Install Gunicorn (for production server):

   pip install gunicorn

Step 3: Push Your Code to GitHub

1. Initialize and push to a new Git repo:

   git init
   git add .
   git commit -m "Initial Flask app"
   git remote add origin https://github.com/yourusername/your-repo.git
   git push -u origin master
   

Step 4: Deploy Using a Web Dashboard (Heroku/Render)

1. On Render or Heroku:
   • Create a new Web Service or App
   • Connect your GitHub repository
   • Build command: pip install -r requirements.txt
   • Start command: gunicorn app:app
   • Click Deploy!
2. Visit your live app URL:
   You’ll receive a unique URL (e.g., https://your-app.onrender.com) to access your Flask app in production.

Summary

• Develop Flask locally, test, and verify
• Prepare deployment files needed for cloud hosting
• Push code to GitHub
• Deploy from a browser-friendly dashboard—no CLI required!
• Share your app with the world!