<?php
// $Id: provision.module,v 1.47.2.21 2008-12-12 19:27:54 anarcat Exp $
/**
* @file
*   Provisioning Framework
*
* This module provides a framework for a Drupal site to manage and install new Drupal sites, using the command line
* Drush utility. 
*
* It allows for pluggable 'provisioning modules' that can extend and modify the tasks that are taken during installation.
*
* Each site has the following commands that can be run on it.
*
* Implemented : 
*   install - Install a new Drupal site. The install command uses 3 separate hooks to do it's job, 
*              namely hook_provision_pre_install(), hook_provision_install() and hook_provision_post_install()
*   verify  - Recreate all configuration files, to be in synch with changes in the front end. And test that they are correct.
*   stats   - Return an associated array of site statistics. (implemented in provision_stats module, is thus optional)
*   import  - Import the details of an already existing site into the provisioning framework.
*             This command inspects the settings.php and generates the site.php file that the framework uses for configuration.
*   backup  - Generates a tarball containing the sites directory, the site data configuration and the database dump.
*             This allows the tarball to act as a 'site package', which can be redeployed on other installations,
*             or used for an upgrade.
*   disable - Disable an installed Drupal site. Changes the virtual host config file so that it redirects to provision_disabled_site_redirect_url
*   enable  - Re-enable a site that has already been disabled. Recreates the virtual host file.
*   delete -  Generates a back up of the site, and then removes all references to it.
*   restore - Revert to a previous backup of the site.
*   cron - Run cron process for a site
*
* Not implemented yet :
*   upgrade - Accepts a site package (backup) as argument, and redeploys it, running the upgrade processes on it.
*             Uses hook_provision_pre_upgrade(), hook_provision_upgrade() and hook_provision_post_upgrade() hooks,
*             and allows clean roll back if any errors occur. Will include stringent checking of module versions,
*             and allow unit tests to be run.
*   rename  - Change the url of a site. This requires moving of files, and numerous other issues.
*/

  // Include the provisioning API. 
  include_once('provision.inc');
  include_once('provision.path.inc');


/**
 * Load additional modules just for this process
 *
 * Load additional modules specified by --load_module_name
 */
function provision_load_from_args() {
  if (!function_exists('drush_verify_cli')) {
    return null;
  }
  global $args;
  $reset = FALSE;
  foreach ($args['options'] as $arg => $value) {
    if (preg_match("/^load-([a-z\-]*)$/", $arg, $matches)) {
      $module = str_replace("-", "_", $matches[1]);
      // find file : can only search under provision path
      $files = file_scan_directory(dirname(__FILE__), "$module.module", array('.', '..', 'CVS'), 0, TRUE, 'name');
      if (isset($files[$module])) {
        provision_log("notice", t("Loading @module on request", array("@module" => $module)));
        $loaded[$module]['name'] = $module;
        $loaded[$module]['filename']  = $files[$module]->filename;
        include_once($loaded[$module]['filename']);
      }
      $reset = TRUE;
    }
  }
  if ($reset && is_array($loaded)) {
    $existing = array();
    $list = module_list(TRUE, FALSE);
    foreach ($list as $module) {
      $existing[$module]['name'] = $module;
      $existing[$module]['filename'] = drupal_get_filename('module', $module);
      drupal_load('module', $module);
    }
    $loaded = array_merge($existing, $loaded);
    module_list(TRUE, FALSE, TRUE, $loaded);
    // Force to regenerate the stored list of hook implementations.
    module_implements('', TRUE, TRUE);
    // As we have missed the bootstrap phase, we need to run
    // our own provision_init hook to initialize modules.
    module_invoke_all('provision_init');
  }
}


/** 
 * Implementation of hook_init
 *
 * Provide defines for all the major paths and settings.
 * These are settings that must not be modified during the running of the
 * program, but are configurable.
 */
function provision_init() {
  // Do not allow the program to be run as the root user. ever
  $name = posix_getpwuid(posix_geteuid());
  if ($name['name'] == 'root') {
    provision_log('error', 'You are running the provision script as the root user. Exiting');
    provision_set_error(PROVISION_FRAMEWORK_ERROR);
    provision_output($url);
  }

  // Load requested additional modules
  provision_load_from_args();

  // Set up defines for platform
  $docroot = provision_get_option(array("r", "root"), $_SERVER['PWD']);
  $backend = provision_get_option(array('b', 'backend'), 0);
  define("PROVISION_DRUSH_BACKEND", $backend);
   
  define('PROVISION_DOMAIN', $_SERVER['HTTP_HOST']);
  // Paths
  $path =  ($docroot) ? $docroot : $_SERVER['DOCUMENT_ROOT'];
  define('PROVISION_DOCROOT_PATH', rtrim($path, '/'));
  define('PROVISION_SITES_PATH', rtrim($path, '/') .'/sites');
  define('PROVISION_DRUSH_PATH', './drush.php');
  $parts = explode("/", rtrim($path, '/'));
  array_pop($parts);
  define('PROVISION_PARENT_PATH', rtrim(implode("/" , $parts), '/'));
  define('PROVISION_BACKUP_PATH', 
    provision_get_option('backup_path', PROVISION_PARENT_PATH . '/backups'));
  define('PROVISION_CONFIG_PATH', 
    provision_get_option('config_path', PROVISION_PARENT_PATH .'/config'));
  define('PROVISION_VHOST_PATH', PROVISION_CONFIG_PATH .'/vhost.d');

  // Commands
  define('PROVISION_RESTART_CMD',
    provision_get_option('restart_cmd', _provision_default_restart_cmd()));

  // System account
  $info = posix_getgrgid(posix_getgid());
  define('PROVISION_WEB_GROUP', 
    provision_get_option('web_group', $info['name'] ));
  define('PROVISION_SCRIPT_USER', 
    provision_get_option('script_user', get_current_user() ));

  // Redirection urls
  define('PROVISION_MASTER_URL', 
    provision_get_option('master_url', variable_get('install_url', $GLOBALS['base_url'])));
  define('PROVISION_WEB_DISABLE_URL', PROVISION_MASTER_URL .'/provision/disabled');
  define('PROVISION_WEB_MAINTENENCE_URL', PROVISION_MASTER_URL .'/provision/maintenance');

  // Database
  define('PROVISION_MASTER_DB', 
    provision_get_option('master_db', $GLOBALS['db_url']));
  $db = parse_url(PROVISION_MASTER_DB);
  define('PROVISION_DB_USER', $db['user']);
  define('PROVISION_DB_PASSWD', $db['pass']);
  define('PROVISION_DB_HOST', $db['host']);
 
  // Drupal does not support multiple types of connections in the same session
  preg_match("$^([a-z]*)://$", $GLOBALS['db_url'], $matches);
  define('PROVISION_DB_TYPE', $matches[1]);
}

function _provision_default_restart_cmd() {
  # try to detect the apache restart command
  $command = '/usr/sbin/apachectl'; # a proper default for most of the world
  foreach (array('/usr/local/sbin/apachectl', # freebsd
                 '/usr/sbin/apache2ctl', # debian + apache2
      $command) as $test) {
    if (is_executable($test)) {
      $command = $test;
    }
  }

  return "sudo $command graceful";
}

/**
 * Generate a provision.settings.php file to configure provision
 */
function _provision_generate_config() {
  provision_log('notice', t("Generating drushrc.php file"));
  provision_path("chmod", PROVISION_DOCROOT_PATH . '/drushrc.php', 0600,
     t('Changed permissions of drushrc.php to @confirm'),
      t('Could not change permissions of drushrc.php to @confirm'));

  provision_save_platform_data();
  provision_path("chmod", PROVISION_DOCROOT_PATH . '/drushrc.php', 0400,
    t('Changed permissions of drushrc.php to @confirm'),
    t('Could not change permissions of drushrc.php to @confirm'));
  return TRUE;
}

/**
 * @defgroup provisionui Configure provisioning framework.
 * @{
 */


/**
 * Implementation of hook_menu().
 */
function provision_menu($may_cache) {
  $items[] = array(
    'path' => 'provision',
    'title' => t('Configure your platform'),
    'description' => t('Configure your platform.'),
    'callback' => 'provision_front',
    'type' => MENU_CALLBACK,
    'access' => TRUE,
  );
  $items[] = array(
    'path' => 'provision/disabled',
    'title' => t('Site disabled'),
    'description' => t('Page showed when a site is disabled.'),
    'callback' => 'provision_disabled_site',
    'type' => MENU_CALLBACK,
    'access' => user_access('access content'),
  );
  $items[] = array(
    'path' => 'provision/maintenance',
    'title' => t('Site is undergoing maintenance.'),
    'description' => t('Page shown when a site is being restored or moved etc.'),
    'callback' => 'provision_site_maintenance',
    'type' => MENU_CALLBACK,
    'access' => user_access('access content'),
  );
  $items[] = array(
    'path' => 'provision/notfound',
    'title' => t('Site not found.'),
    'description' => t('The site you have requested is not available.'),
    'callback' => 'provision_site_notfound',
    'type' => MENU_CALLBACK,
    'access' => user_access('access content'),
  );
  return $items;
}

function provision_front() {
  if (variable_get('provision_setup', FALSE)) {
    drupal_goto('provision/notfound');
  }
  #return _provision_requirements("provision_setup");
}

function provision_disabled_site() {
  drupal_set_breadcrumb(array());
  return "<p>This site was disabled by the site administrators.</p>";
}

function provision_site_maintenance() {
  drupal_set_breadcrumb(array());
  return "<p>This site is being worked on presently. Check back later.</p>";
}

function provision_site_notfound() {
  drupal_set_breadcrumb(array());
  return "<p>The site you have requested does not exist.</p>";
}

/**
 * @} End of "defgroup provisionui"
 */


/**
 * @defgroup provisiondrush Command line interface for Provision.
 * @{
 */
/**
 * Implementation of hook_drush_command().
 */
function provision_drush_command() {
  
  $items['provision install'] = array(
    'callback' => 'provision_install_cmd',
    'arguments' => array('domain.com' => t('The domain of the site to install.')),
    'description' => t('Provision a new site using the provided data.')
  );

  $items['provision import'] = array(
    'callback' => '_provision_import',
    'arguments' => array('domain.com' => t('The domain of the site to import.')),
    'description' => t('Turn an already running site into a provisioned site.')
  );
  
  $items['provision backup'] = array(
    'callback' => '_provision_backup',
    'arguments' => array('domain.com' => t('The domain of the site to back up.')),
    'optional arguments' => array('backup-file' => t('The file to save the backup to. This will be a gzipped tarball.')),
    'description' => t('Generate a back up for the site.')
  );
  
  $items['provision enable'] = array(
    'callback' => '_provision_enable',
    'arguments' => array('domain.com' => t('The domain of the site to enable (only if enabled).')),
    'description' => 'Enable a disabled site.'
  );
  $items['provision disable'] = array(
    'callback' => '_provision_disable',
    'arguments' => array('domain.com' => t('The domain of the site to disable (only if disabled).')),    
    'description' => 'Disable a site.'
  );

  $items['provision verify'] = array(
    'callback' => '_provision_verify',
    'arguments' => array('domain.com' => t('The domain of the site to verify).')),    
    'description' => 'Verify that the provisioning framework is correctly installed.'
  );
 
  $items['provision restore'] = array(
    'callback' => '_provision_restore',
    'description' => 'Restore the site to a previous backup. This will also generate a backup of the site as it was.',
    'arguments' => array('domain.com' => t('The domain of the site to be restored'),
                    'site_backup.tar.gz' => t('The backup to restore the site to.'))
  );
 
  $items['provision delete'] = array(
    'callback' => '_provision_delete',
    'description' => 'Delete a site.'
  );

  $items['provision cron'] = array(
    'callback' => '_provision_cron',
    'description' => 'Run cron process for site.',
    'arguments' => array('domain.com' => t('The domain of the site to be processed'))
  );
 
  if (!function_exists('hosting_setup')) {
    $items['provision setup'] = array(
      'callback' => '_provision_setup_cmd',
      'description' => 'Initialize this platform to be able to create hosted sites.',
    );
  }

  /*
  // Not implemented yet.
  $items['provision deploy'] = array(
    'callback' => '_provision_deploy',
    'description' => 'Deploy a backup made on another provisioning platform on this one.'
  );
  $items['provision rename'] = array(
    'callback' => '_provision_rename',
    'description' => 'Change the url of an existing site.'
  );

  */
  return $items;
}

/**
 * Drush callback function
 *
 * Installs a new site at $url.
 * It does so by calling hook_provision_pre_install(), hook_provision_install() and hook_provision_post_install().
 *
 * @param url
 *    The url of the site being installed.
 * @return
 *    Returns provision_output on success or error. 
 *    Will exit with a PROVISION_SITE_INSTALLED error if the site already exists.
 *    Will exit with a PROVISION_FRAMEWORK_ERROR if the command is incorrectly used.
 */
function provision_install_cmd($url) {
  global $args;
  $data = provision_get_site_data($url);

  if (!$args['commands'][2]) {
    print "Usage: drush.php provision install DOMAIN [OPTIONS]\n";
    print "Install a new site for the domain DOMAIN.\n";
    print "Example: drush.php provision install mydomain.com --site-db-host localhost\n";
    provision_log("error", "Incorrect usage of the provisioning framework");
    provision_set_error(PROVISION_FRAMEWORK_ERROR);
    provision_output($url, $data);
  }
  if (provision_invoke("install", $url, $data)) {
    provision_save_site_data($url, $data);
  }
  provision_output($url, $data);
}

/**
 * Generate a backup of the site using a site package.
 *
 * @param url
 *   The url of the site being backed up.
 * @return
 *   Output of provision_output() function.
 *   Will exit with a PROVISION_SITE_NOT_FOUND error if the site does not exist.
 */
function _provision_backup($url) {
  if (!_provision_drupal_site_installed($url)) {
    provision_log("Error", "Site has not been installed yet.");
    provision_set_error(PROVISION_SITE_NOT_FOUND);
    provision_output($url, $data);
  }
  $data = provision_get_site_data($url);
  $args = func_get_args();
  array_shift($args);
  $file = array_shift($args);
  _provision_backup_site($url, $data, $file);

  $data['installed'] = TRUE;
  provision_save_site_data($url, $data);
   
  provision_output($url, $data);
}

/**
 * Generate a backup tarbal for a site.
 */
function _provision_backup_site($url, &$data, $file = NULL) {
  // This is the actual drupal provisioning requirements. 
  if (!is_dir(PROVISION_BACKUP_PATH)) {
    provision_log("Backup directory does not exist.");
    provision_set_error(PROVISION_PERM_ERROR);
    provision_output($url, $data);
  }
  
  if (is_file($file)) {
    provision_log("File specified already exists.");
    provision_set_error(PROVISION_PERM_ERROR);
    provision_output($url, $data);
  }
  $suggested = PROVISION_BACKUP_PATH ."/$url-". date("Y-m-d", mktime()) .".tar";

  // Use format of mysite.com-2008-01-02, if already existing, add number.
  while (is_file($suggested .'.gz')) {
    $count++;
    $suggested = PROVISION_BACKUP_PATH ."/$url-". date("Y-m-d", mktime()) ."_$count.tar";
  }

  $data['backup_file'] = (!empty($file)) ? ereg_replace('.gz$', '', $file) : $suggested;
  provision_invoke("backup", $url, $data);
  provision_shell_exec("gzip %s", $data['backup_file']);
  $data['backup_file'] = $data['backup_file'] .'.gz';
}

/**
 * Import a running Drupal site into a provisioned site.
 *
 * This is accomplished by inspecting the settings.php file and generating a site.php file.
 *
 * @param url
 *   The url of the site being synched.
 * @return
 *   Output of provision_output() function.
 *   Will exit with a PROVISION_SITE_NOT_FOUND error if the site does not exist.
 */
function _provision_import($url) {
  if (!$url) {
    print "Usage: drush.php provision import DOMAIN\n";
    provision_set_error(PROVISION_FRAMEWORK_ERROR);
    provision_output($url, $data);
  }
  provision_invoke("import", $url, $data);
  provision_output($url, $data);
}


/**
 * Import a running Drupal site into a provisioned site.
 *
 * This is accomplished by inspecting the settings.php file and generating a site.php file.
 *
 * @param url
 *   The url of the site being verified. 
 *   Optional, if no site is specified the platform will be verified
 * @return
 *   Output of provision_output() function.
 *   Will exit with a PROVISION_SITE_NOT_FOUND error if the site specified does not exist.
 */
function _provision_verify($url = NULL) {
  if (!$url) {
    // we are verifying a platform
    $data = array();
    _provision_create_dir(PROVISION_CONFIG_PATH, t('Provision configuration'), 0755);
    _provision_create_dir(PROVISION_BACKUP_PATH, t('Web server configuration'), 0700);
  }
  else {
    // we are verifying a site
    if (!_provision_drupal_site_installed($url)) {
      provision_log("error", "Site has not been installed yet.");
      provision_set_error(PROVISION_SITE_NOT_FOUND);
      provision_output();
    }
    $data = provision_get_site_data($url);
  }

  
  // We only save the settings if they validated correctly, not before.
  if (provision_invoke("verify", $url, $data)) {
    if (!$url) {
      _provision_generate_config();
    }
    else {
      provision_save_site_data($url, $data);
    }
  }

  provision_output($url, $data);
}

/**
 * Restore command implementation
 *
 * This command when called will 
 *   1. Make a backup of the current site, before modifications are made.
 *   2. Temporarily disable the site by causing apache to redirect to a help page. Restarting apache is required.
 *   3. Extract the backup that is being restored to to a temporary folder in the sites directory.
 *   4. Create a new database, belonging to the site's user, and switch it around with the current site's database.
 *   5. Import the old database and site.php details.
 *   6. Switch around the sites directory of the current site and the backup being restored.
 *   7. Regenerate configuration files.
 *   8. TODO: diagnostic to test that everything is ok?
 *   9. Remove the temporary redirect and restart apache so the previous site is available again.
 *   10. Remove the extranuous db and duplicate site directory.
 *
 * If at any time an error occurs, before step 9. It should reverse all the changes it has made,
 * and leave the current site directory and database in the right place, and remove all cruft that
 * was created by this process.
 */
function _provision_restore($url, $restore_file) {
  if (!($exists = _provision_drupal_site_installed($url))) {
    // this can probably be done more consistently with another
    // provision_path like function.
    provision_log("Error", "Site has not been installed yet.");
    provision_set_error(PROVISION_SITE_NOT_FOUND);
  }

  $exists &= provision_path("exists", $restore_file, TRUE,
      t("Restoring site from @path"),
      t("Could not find backup file @path"),
      PROVISION_FRAMEWORK_ERROR);

  if ($exists) {
    $data = provision_get_site_data($url);
    $data['restore_file'] = $restore_file;

    if (provision_invoke("restore", $url, $data)) {
      provision_save_site_data($url, $data);
    }
  }
  provision_output($url, $data);
}

function provision_provision_pre_restore($url, &$data) {
  _provision_backup_site($url, $data); // Backup site for posterity, before rolling back.

  provision_path("extract", $data['restore_file'], PROVISION_SITES_PATH ."/$url.restore", 
    t('Successfully extracted the contents of @path to @confirm'),
    t('Failed to extract the contents of @path to @confirm'),
    PROVISION_PERM_ERROR, PROVISION_FRAMEWORK_ERROR);
}

function provision_provision_pre_restore_rollback($url, $data) {
  _provision_recursive_delete(PROVISION_SITES_PATH ."/$url.restore");
}

function provision_provision_post_restore($url, $data) {
  _provision_recursive_delete(PROVISION_SITES_PATH ."/$url.restore");
}

function _provision_disable($url) {
  if (!_provision_drupal_site_installed($url)) {
    provision_log("Error", "Site has not been installed yet.");
    provision_set_error(PROVISION_SITE_NOT_FOUND);
    provision_output($url, $data);
  }
  $data = provision_get_site_data($url);
  _provision_backup_site($url, $data); # Backup site for posterity, before disabling 

  if (provision_invoke("disable", $url, $data)) {
    $data['enabled'] = FALSE;
    provision_save_site_data($url, $data);
  }

  provision_output($url, $data);
}

function _provision_enable($url) {
  if (!_provision_drupal_site_installed($url)) {
    provision_log("Error", "Site has not been installed yet.");
    provision_set_error(PROVISION_SITE_NOT_FOUND);
    provision_output($url, $data);
  }
  $data = provision_get_site_data($url);

  if (provision_invoke("enable", $url, $data)) {
    $data['enabled'] = TRUE;
    provision_save_site_data($url, $data);  
  } 

  provision_output($url, $data);
}

function _provision_delete($url) {
  $data = provision_get_site_data($url);
  $args = func_get_args();
  array_shift($args);
  $file = array_shift($args);
  _provision_backup_site($url, $data, $file);

  provision_invoke("delete", $url, $data);

  provision_output($url, $data);
}

/**
 * Initial setup of platform
 * 
 * Creates symlink to drush.php
 * Creates config path
 * Creates drushrc path
 *
 * This function is re-used by the hosting_setup command, as it is a superset of this functionality.
 */
function _provision_setup() {
  $success = TRUE;
  $drush_path = sprintf("%s/%s/drush.php", PROVISION_DOCROOT_PATH, drupal_get_path('module', 'drush'));

  $success &= provision_path('symlink', $drush_path, PROVISION_DOCROOT_PATH . '/drush.php', 
    t('Created symlink for drush.php file'), 
    t('Could not create symlink for drush.php'), 
    PROVISION_FRAMEWORK_ERROR);

  $success &= _provision_generate_config();
  return $success; 
}

/**
 * Drush command wrapper for the setup of the platform
 */
function _provision_setup_cmd() {
  if (_provision_setup()) {
    variable_set('provision_setup', TRUE); 
  }
 
  // @TODO use provision_output for this, but we need pretty print first.
  $logs = provision_get_log();
  foreach ($logs as $log) {
    print "$log[message]\n";
  }

  if (provision_get_error()) {
    print "\nThe command did not complete successfully, please fix the issues and re-run this script.";
  }
}

/**
 * Drush command to run cron
 */
function _provision_cron($url) {
  if (!_provision_drupal_site_installed($url)) {
    provision_log("Error", "Site has not been installed yet.");
    provision_set_error(PROVISION_SITE_NOT_FOUND);
    provision_output($url, $data);
  }
  $data = provision_get_site_data($url);
  _provision_drupal_switch_active_site($url);
  drupal_cron_run();
  _provision_drupal_switch_active_site();
   
}