Deploy Python Flask App on Heroku

Flask is a web application framework written in Python. Flask is based on the Werkzeug WSGI toolkit and Jinja2 template engine. Both are Pocco projects. This article revolves around how to deploy a flask app on Heroku. To demonstrate this, we are first going to create a sample application for a better understanding of the process. 

Prerequisites 

• Python
• pip
• Heroku CLI
• Git

Deploying Flask App on Heroku

Let’s create a simple flask application first and then it can be deployed to heroku. Create a folder named “eflask” and open the command line and cd inside the “eflask” directory. Follow the following steps to create the sample application for this tutorial.
STEP 1 : Create a virtual environment with pipenv and install Flask and Gunicorn .

$ pipenv install flask gunicorn 

STEP 2 : Create a “Procfile” and write the following code. 

$ touch Procfile 

STEP 3 : Create “runtime.txt” and write the following code.

$ touch runtime.txt 

STEP 4 : Create a folder named “app” and enter the folder. 

$ mkdir app
$ cd app
  

STEP 5 : Create a python file, “main.py” and enter the sample code.

 touch main.py 

Python3

from flask import Flask

app = Flask(__name__)

@app.route("/")
def home_view():
        return "<h1>Welcome to Geeks for Geeks</h1>"

STEP 6 :Get back to the previous directory “eflask”.Create a file“wsgi.py” and insert the following code.

$ cd ../
$ touch wsgi.py

Python3

from app.main import app

if __name__ == "__main__":
        app.run()

STEP 7 : Run the virtual environment.

$ pipenv shell 

STEP 8 : Initialize an empty repo, add the files in the repo and commit all the changes.

$ git init 
$ git add .
$ git commit -m "Initial Commit"

STEP 9 : Login to heroku CLI using 

heroku login

Now, Create a unique name for your Web app.

$ heroku create eflask-app

STEP 10 : Push your code from local to the heroku remote. 

$ git push heroku master

Finally, web app will be deployed on http://eflask-app.herokuapp.com.