Yii Framework cache busting with Git and some magic page post-processing.

Controller.php

public function processOutput($output) {
    $output = parent::processOutput($output);

    $output = str_replace('.css', '.css?' . Yii::app()->params['git-hash'], $output);
    $output = str_replace('.js', '.js?' . Yii::app()->params['git-hash'], $output);

    return $output;
}

main.php

$output = array();
$gitHash = exec('git rev-parse --verify HEAD 2> /dev/null', $output); // Thanks to AD7six (http://stackoverflow.com/a/9193040/704939)
$gitHash = $output[0];

return array(
    /* All your configuration settings down to params */
    'params' => array(
        'git-hash' => $gitHash,
    ),
);