automatically add aliases from external hosts

[guaka]

Here's the code I'm using myself, it's a neat way to get a whole bunch of aliases on your dev machine. #1485 was causing trouble with this...

function my_add_aliases($aliases) {
  $d_locations = array(array('example.com', '/var/www/drupal7'),
                       array('host2.example.com', '/var/www/drupal7'),
                       array('host2.example.com', '/var/www/drupal6'),
);

  foreach ($d_locations as $host_path) {
    $host = $host_path[0];
    $path = $host_path[1];
    $dd_path = '~/.drush/';  // dot drush // THE ~ PART MIGHT NOT WORK AS IS
    $f_cache_list = 'site-list-cache-' . $host . str_replace('/', "-", $path);
    if ((time()-filectime($dd_path . $f_cache_list)) > 86400) {
      $cmd = "ssh $host ls $path/sites > " . $dd_path . $f_cache_list;
      // echo $cmd . "\n";
      drush_shell_exec($cmd);
    }
    $sites = file($dd_path . $f_cache_list);

    foreach ($sites as $k => $v) {
      $s = trim($v);
      $aliases[$s] = array(
                           'uri' => $s,
                           'root' => $path,
                           'remote-host' => $host,
                           );
    }
  }
  return $aliases;
}

$aliases = my_add_aliases($aliases);

Just wrote this quickly to scratch an itch and not sure how to properly turn this into a patch.

[guaka]

Feel free to add this to official drush (under GPL I guess?). I'd also be happy do it myself if I get a wee bit of guidance.

[weitzman]

Clever. I have long wanted a chef-like system where Drush would consult an external server for its site aliases, commands, etc. When we build that, we would probably just rsync the files into position whenever cron tells us to. That way, the Drush alias system continues to work as today.