WordPress getenv

functions.php

<?php

/**
 * Get option value, unless we are in debug mode && that key is set in the environment
 */
function get_environment_variable($varname) {
    if (!is_string($varname)) throw new Exception('Strings only.');
    if (getenv('WP_DEBUG')) {
        return (getenv(strtoupper($varname))) ? : get_option($varname);
    }
        return get_option($varname);
}