Re: [PATCH] Adding stressor validation for stress-ng

Hi Sana,

Thanks for the patch! The validation logic looks good and the error messages are helpful.

One request: could you move `get_valid_stressors()` and `validate_stressor()`
out of the class and make them module-level functions? They don't need access to
the class instance, and module-level functions are easier to unit test and can be
imported directly.

Place them after the imports and before the class definition:

def get_valid_stressors():
    """Query stress-ng for list of valid stressor names."""
    try:
        result = subprocess.run(['stress-ng', '--stressors'],
                              capture_output=True, text=True, check=True)
        return result.stdout.strip().split()
    except (subprocess.CalledProcessError, FileNotFoundError):
        return []

def validate_stressor(stressor_name):
    """Validate a single stressor name against stress-ng's available stressors."""
    valid = get_valid_stressors()
    if not valid:
        return

    if stressor_name not in valid:
        raise ValueError(f"Invalid stress-ng stressor: '{stressor_name}'. "
                        f"Run 'stress-ng --stressors' to see valid options.")

Then call it in _WorkloadPrepare() as: validate_stressor(self.cfg.stressor)

Thanks!
John