Web Development with Flask: Deploying Flask Applications

Introduction
Prerequisites
Setup
Creating a Flask Application
Deploying the Flask Application
Conclusion

Introduction

In this tutorial, you will learn how to deploy Flask applications. Flask is a popular and lightweight web framework for Python. By the end of this tutorial, you will be able to deploy your Flask applications to a web server, making them accessible to users online.

Prerequisites

Before starting this tutorial, you should have a basic understanding of Python programming language and some familiarity with Flask framework. If you are new to Flask, it is recommended to go through the Flask documentation and get a basic understanding of how Flask applications work.

Setup

To follow along with this tutorial, you need to have Flask installed on your system. You can install Flask using pip, the Python package installer. Open your terminal or command prompt and run the following command: pip install flask Once Flask is installed, you are ready to create your Flask application.

Creating a Flask Application

Open your preferred code editor and create a new directory for your Flask application.
Inside the directory, create a new Python file named app.py.

Import Flask and create an instance of the Flask class:

 from flask import Flask
	
 app = Flask(__name__)

Define a route and a function that will be executed when that route is accessed:
```
 @app.route('/')
 def hello():
     return "Hello, World!"
```
Save the file and open your terminal or command prompt.
Navigate to the directory where your app.py file is located.
Start the Flask development server by running the following command:
```
 flask run
```
You should see an output indicating that the server is running.
Open your web browser and visit http://localhost:5000. You should see the message “Hello, World!” displayed on the page.

Congratulations! You have created a basic Flask application. Now, let’s move on to deploying the application.

Deploying the Flask Application

Before deploying your Flask application, you need to choose a hosting provider. There are many options available, such as Heroku, PythonAnywhere, or a cloud service like Amazon Web Services (AWS) or Microsoft Azure. For the purpose of this tutorial, we will use Heroku.
Sign up for a free Heroku account at https://www.heroku.com.
Install the Heroku command-line interface (CLI) by following the instructions provided in the Heroku documentation.
Once the CLI is installed, open your terminal or command prompt and log in to your Heroku account by running the following command:
```
 heroku login
```
In your Flask application directory, initialize a new Git repository by running the following command:
```
 git init
```
This step is necessary as Heroku uses Git for deployment.
Create a file named Procfile (without any extension) in your Flask application directory. Open the file and add the following line:
```
 web: gunicorn app:app
```
This tells Heroku to use the Gunicorn server to run your Flask application.
Commit your changes to the Git repository by running the following commands:
```
 git add .
 git commit -m "Initial commit"
```
Create a new Heroku app by running the following command:
```
 heroku create
```
This will generate a unique name for your app and add a new remote repository called heroku to your Git configuration.
Deploy your Flask application to Heroku by running the following command:
```
 git push heroku master
```
This will upload your code to Heroku and automatically build and deploy your application.
Once the deployment is complete, you can visit your application by running the following command:
```
heroku open
```
This will open your application in your default web browser.

Congratulations! You have successfully deployed your Flask application to Heroku.

Conclusion

In this tutorial, you have learned how to deploy Flask applications. We started by creating a basic Flask application and then deployed it to a hosting provider using Heroku as an example. By following the steps outlined in this tutorial, you can deploy your Flask applications and make them accessible to users online. Remember to choose a hosting provider that suits your needs and explore their specific documentation for more details on deployment options and configuration.

Now it’s time for you to take your Flask application to the next level and deploy it to the world!

Happy coding!

Published: 18 August 2020