# Installing and configuring Flask on a Linux shared hosting account

> Create a Python application in cPanel and set up a Flask project on your Linux shared hosting account.

Source: https://helpcenter.ruachost.com/developers/programming-languages/installing-and-configuring-django-on-linux-shared-hosting/

## Installing and configuring Flask on a Linux shared hosting account

Flask is a lightweight Python framework for building web applications. This guide shows how to install and configure a Flask application on a Linux shared hosting account using cPanel.

> **Caution:**
This configuration is tested on shared hosting accounts but is not officially supported. Use it as a starting point for your own projects. Custom troubleshooting is not provided.

## Step 1: Create a Python application in cPanel

1. Log in to **cPanel**.
2. In the **Software** section, click **Setup Python App**.
3. Click **CREATE APPLICATION**.
4. In the application form:

   - **Python version:** Select your preferred version (e.g., Python 3.7.3).
   - **Application root:** Type `flaskapp`.
   - **Application URL:** Select the domain and type `flaskapp`.
   - Leave **Application startup file** and **Application entry point** blank (cPanel will generate `passenger_wsgi.py` automatically).
   - Optionally, specify a **Passenger log file**.
5. Click **CREATE** to set up the application and its virtual environment.
6. Note the command displayed to **enter the virtual environment**; you’ll need it in the next step.

## Step 2: Configure the Flask project

1. Log in via SSH.
2. Activate the virtual environment (replace the path with the command noted in Step 1):

```
source /home/username/virtualenv/flaskapp/3.7/bin/activate && cd /home/username/flaskapp
```

The prompt now shows `(flaskapp:3.7)` to indicate the virtual environment is active.

3. Install Flask:

```
pip install flask
```

4. Verify the Flask version:

```
flask --version
```

5. Edit the `passenger_wsgi.py` file (`~/flaskapp/passenger_wsgi.py`) with the following contents:

```

from flask import Flask, request, render_template, redirect, url_for

project_root = os.path.dirname(os.path.realpath('__file__'))
template_path = os.path.join(project_root, 'app/templates')
static_path = os.path.join(project_root, 'app/static')
app = Flask(__name__, template_folder=template_path, static_folder=static_path)

@app.route('/')
def index():
    return 'Hello from flask'

application = app
```

6. Restart the Python application in cPanel:

   - Go to **Setup Python App** under **SOFTWARE**.
   - Locate the `flaskapp` application and click the **Restart** icon.
7. Test the Flask site in a browser:

```
http://www.example.com/flaskapp
```

You should see the page:

```
Hello from flask
```

Tip: If the page doesn’t appear, run the `passenger_wsgi.py` file manually to check for syntax errors:

```
python ~/flaskapp/passenger_wsgi.py
```

## More information

- [Flask Official Documentation](https://flask.palletsprojects.com/)