Running a python script within a Joomla 4 component gets return value of 2. How do I get Joomla to run the script successfully?

Question

I'm writing a custom Joomla 4 component, and when I try to run python code within the Model php file to pass to the View, the exec command returns an resultValue of 2.

• The python code is valid
• The python code is executible for everyone 0755 permissions
• The webpage returns the result value of two (as per my return of $resultValue instead of result)
• The webpage of course returns nothing if I return $result instead

cat site/src/Model/WeatherModel.php 
<?php
namespace Vim\Component\com_vimsjoomlaweather\Site\Model;

#error checking
error_reporting(E_ALL);
ini_set('display_errors', 1);

use Joomla\CMS\MVC\Model\BaseDatabaseModel;

class WeatherModel extends BaseDatabaseModel {
  public function getWeatherData() {
        exec('python ./weathermodel.py', $result, $returnValue);
        return $returnValue;
  }
}

cat site/src/Model/weathermodel.py 
def get_weather_data():
    print(['weather data in print'])
    return ["weather data"]

if __name__ == '__main__':
    get_weather_data()

Also, this may need it's own ask, but the manifest xml document doesn't add the necessary permissions, and I am having to add them myself after component installation.

• is <file mode="0755">src/Model/weathermodel.py</file> written wrong?

        <folder>src</folder>
        <folder>tmpl</folder>
    </files>
    <files folder="site/">
        <filename>src/Model/weathermodel.py</filename>
        <file mode="0755">src/Model/weathermodel.py</file>
    </files>```

Answer 1

Component not running python script, return value 2

Turns out PHP files inherit Joomla's working directory. The cwd ends up as the Joomla's working directory so /path/to/joomla just for clarity this does not end up being the components root directory. A simple way to get around this is to chdir in php.

chdir(__DIR__);
exec('python weathermodel.py', $result, $returnValue);

File permissions not being set at extension installation

Second issue about file permissions not being set well there doesn't seem to be a way to do that in the XML manifest file. But I deleted the extension and readded with the corrected version, as shown above and it works! It works because the python interpreter isn't held back by Linux permission bits.

A note on permissions

Even though the permissions are set as 644 / -rw-r--r--. it still runs. My guess is because it's being ran by the python interpreter and not BASH therefore file permissions don't come into play. I believe this to be the case since, I created another file called weathermodel.sh

• when I set the permissions to 644 I don't get data back! and it comes back with a return value of 126.
• But when I set the permissions to that file as 755 I get a return value of 0 and I get the data I want. If you want to add a BASH script with proper permissions on installation you'll probably have to add some sort of bootstrap file, I think..

In Summary

• PHP files inherit Joomla's current working directory
• Manifest files seem to not have the functionality set Linux permission bits
• Result value 2: file not found
• Result value 126: permissions issue
• Result value 0: all well