Pantheon Primary Domain + HTTPS Redirect

/ Redirect all traffic to non-www. For example yoursite.com
if (isset($_SERVER['PANTHEON_ENVIRONMENT']) &&
  ($_SERVER['PANTHEON_ENVIRONMENT'] === 'live') &&
  // Check if Drupal or WordPress is running via command line
  (php_sapi_name() != "cli")) {
  if ($_SERVER['HTTP_HOST'] == 'www.youwebsite.com') {
    header('HTTP/1.0 301 Moved Permanently');
    header('Location: https://yourwebsite.com'. $_SERVER['REQUEST_URI']);
    exit();
  }
}

// Require HTTPS.
if (isset($_SERVER['PANTHEON_ENVIRONMENT']) &&
  ($_SERVER['HTTPS'] === 'OFF') &&
  // Check if Drupal or WordPress is running via command line
  (php_sapi_name() != "cli")) {
  if (!isset($_SERVER['HTTP_X_SSL']) ||
  (isset($_SERVER['HTTP_X_SSL']) && $_SERVER['HTTP_X_SSL'] != 'ON')) {
    header('HTTP/1.0 301 Moved Permanently');
    header('Location: https://'. $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']);
    exit();
  }
}