drush archive-dump gets an Aegir specific settings.php

Doing an

drush "@$ALIAS" archive-dump --destination=$TEMPFILE --tar-options="--exclude=drushrc.php"

on an Aegir managed site I get VHOST specific code in settings.php like

  /**
   * The database credentials are stored in the Apache vhost config
- cut -
   * This is a security measure implemented by the Aegir project.
   */
  $databases['default']['default'] = array(
    'driver' => $_SERVER['db_type'],
    'database' => $_SERVER['db_name'],
    'username' => $_SERVER['db_user'],
    'password' => $_SERVER['db_passwd'],
    'host' => $_SERVER['db_host'],
    'port' => $_SERVER['db_port'],
  );
  $db_url['default'] = $_SERVER['db_type'] . '://' . $_SERVER['db_user'] . ':' . $_SERVER['db_passwd'] . '@' . $_SERVER['db_host'] . ':' . $_SERVER['db_port'] . '/' . $_SERVER['db_name'];

which causes notices on every page for the restored site on a non-Aegir install.

    Notice: Undefined index: db_type in include_once() (line 24 of /path/to/site/settings.php).
    Notice: Undefined index: db_name in include_once() (line 25 of /path/to/site/settings.php).
    Notice: Undefined index: db_user in include_once() (line 26 of /path/to/site/settings.php).
    Notice: Undefined index: db_passwd in include_once() (line 27 of /path/to/site/settings.php).
    Notice: Undefined index: db_host in include_once() (line 28 of /path/to/site/settings.php).
    Notice: Undefined index: db_port in include_once() (line 29 of /path/to/site/settings.php).
    Notice: Undefined index: db_type in include_once() (line 31 of /path/to/site/settings.php).
    Notice: Undefined index: db_user in include_once() (line 31 of /path/to/site/settings.php).
    Notice: Undefined index: db_passwd in include_once() (line 31 of /path/to/site/settings.php).
    Notice: Undefined index: db_host in include_once() (line 31 of /path/to/site/settings.php).
    Notice: Undefined index: db_port in include_once() (line 31 of /path/to/site/settings.php).
    Notice: Undefined index: db_name in include_once() (line 31 of /path/to/site/settings.php).

We could wrap this by testing for

if (isset($_SERVER['db_name'])) {
  /**
   * The database credentials are stored in the Apache vhost config
- cut -
   */
  $databases['default']['default'] = array(
- cut-
  );
  $db_url['default'] = $_SERVER['db_type'] . '://' . $_SERVER['db_user'] . ':' . $_SERVER['db_passwd'] . '@' . $_SERVER['db_host'] . ':' . $_SERVER['d
b_port'] . '/' . $_SERVER['db_name'];
}

Running

drush archive-restore --destination=/path/to/www/root --db-url=mysql://x_dev:x_dev@localhost/x_dev /archives/backup-x_prod-latest.tar.gz

adds its own db connection to the end of settings.php