lhotakj / flask-vercel-demo

Simple Web Application running hosted on Vercel

A simple web application demo of Python Flask hosted on free plan (hobby) on Vercel Serverless Functions. Demo can be seen at https://flask.lhotak.net/ and https://flask.lhotak.net/heartbeat

Preamble

• If you want to use Vercel for hosting your production using a hobby plan be aware of certain limitations.
• Vercel currently supports (only) Python 3.9 released back in 2020 see doc
• Vercel Serverless Functions is primarily built for Type Script web apps, don't expect much Python support
• In addition to the serverless functions Vercel platform a couple of serverless storage products:
  • Vercel KV: Durable Redis - preferred option of key-value data
  • Vercel Postgres: Serverless SQL - preferred option when relation database is required
  • Vercel Blob: Large file storage
  • Vercel Edge Config: Global, low-latency data store
• But it's free, so why not to try it out?

Flask extensions

• CORS - handling Cross Origin Resource Sharing
• Whitenoise - simplified static file serving without relying on Nginx

1. Install Python 3

Ubuntu 22.04 and Python

sudo apt-get install -y -q python3 python3-setuptools python3-dev build-essential

2. Install and Configure Web Server

Install Python Flask dependency

pip install -r ./requirements.txt

• Copy app.py or download it from source repository

3. Start Web Server

Start web server

FLASK_APP=app.py flask run --host=0.0.0.0

4. Test

Open a browser and go to URL

http://<IP>:5000/                           => Hello world
http://<IP>:5000/heartbeat                  => ok

Credits

• https://github.com/harshan1996/flask-vercel/blob/main/backend/views.py
• https://vercel.com/docs/functions/serverless-functions/runtimes/python