hosting_reserve.module

<?php

/**
 * @file
 *   Hosting reserve functions, and Drupal hooks.
 */

define('HOSTING_RESERVE_DEFAULT_CLONE_DOMAIN', 'clone');

/**
 * Implementation of hook_menu().
 */
function hosting_reserve_menu() {
  $items['admin/hosting/reserve'] = array(
    'title' => 'Site Reserve',
    'description' => 'Configure settings for hosting site reserve',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('hosting_reserve_settings'),
    'access arguments' => array('administer modules'), // TODO find good permission
    'type' => MENU_LOCAL_TASK,
  );
  return $items;
}

/**
 * Configuration form for hosting_reserve
 */
function hosting_reserve_settings() {
  $form['hosting_reserve_full_size'] = array(
    '#type' => 'textfield',
    '#title' => t('Full reserve size'),
    '#description' => t('The maximum number of sites in the reserve. The template will be cloned until this number is reached.'),
    '#default_value' => variable_get('hosting_reserve_full_size', '10'),
    '#required' => TRUE,
    '#weight' => -15,
  );

  $form['hosting_reserve_minimum_size'] = array(
    '#type' => 'textfield',
    '#title' => t('Minimum reserve size'),
    '#description' => t('The minimum number of sites in the reserve to try to preserve at all times. When there are fewer than this many reserve sites, we ignore the refilling time window restrictions (see lower). Set to zero to allow full depletion between time windows.'),
    '#default_value' => variable_get('hosting_reserve_minimum_size', '1'),
    '#weight' => -10,
  );

  $form['hosting_reserve_clone_life_time'] = array(
    '#type' => 'textfield',
    '#title' => t('Clone life time (in hours)'),
    '#description' => t('Set to zero for infinite. Clones will be deleted if they stay in the "reserve" this long. Clone deletion will only occur within the refill window.'),
    '#default_value' => variable_get('hosting_reserve_clone_life_time', '23'),
    '#weight' => -5,
  );

  $server_time_message = t('The current server time is @time', array('@time' => date("H:i")));


  $form['hosting_reserve_refill_window'] = array(
    '#type' => 'fieldset',
    '#title' => t('Time window for refilling'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
    '#description' => t("Unless the reserve is depleted under the \"minimum reserve size\",  if you don't limit the hours, the reserve will always be refilling. This could slow down the time between request delivery if you have a few back-to-back, since clone and import tasks would run in-between the renaming tasks."),
    '#weight' => -1,
    '#prefix' => '<br/>',
    '#suffix' => '<br/>',
  );

  $form['hosting_reserve_refill_window']['hosting_reserve_refill_window_start'] = array(
    '#type' => 'textfield',
    '#title' => t('Start refilling the reserve at this hour.'),
    '#description' => t('Format: 00:00. ') . $server_time_message,
    '#default_value' => variable_get('hosting_reserve_refill_window_start', '00:00'),
    '#maxlength' => 5,
    '#size' => 6,
    '#prefix' => '<br/>',
  );

  $form['hosting_reserve_refill_window']['hosting_reserve_refill_window_end'] = array(
    '#type' => 'textfield',
    '#title' => t('Stop refilling the reserve at this hour.'),
    '#description' => t('Format: 23:59. ') . $server_time_message,
    '#default_value' => variable_get('hosting_reserve_refill_window_end', '04:00'),
    '#maxlength' => 5,
    '#size' => 6,
  );

  $form['#validate'][] = 'hosting_reserve_settings_form_validate';

  return system_settings_form($form);
}

function hosting_reserve_settings_form_validate(&$form, &$form_state) {
  $date_format = 'H:i';

  $values = $form_state['values'];

  if (!empty($values['hosting_reserve_refill_window_start'])) {
    if (strtotime($values['hosting_reserve_refill_window_start']) == 0) {
      form_set_error('hosting_reserve_refill_window_start', t('Invalid start time'));
    }
  }

  if (!empty($values['hosting_reserve_refill_window_end'])) {
    if (strtotime($values['hosting_reserve_refill_window_end']) == 0) {
      form_set_error('hosting_reserve_refill_window_end', t('Invalid end time'));
    }
  }

  if (empty($values['hosting_reserve_refill_window_start'])) {
    $form_state['values']['hosting_reserve_refill_window_start'] = '00:00';
  }

  if (empty($values['hosting_reserve_refill_window_end'])) {
    $form_state['values']['hosting_reserve_refill_window_end'] = '23:59';
  }

  if (empty($values['hosting_reserve_minimum_size'])) {
    $form_state['values']['hosting_reserve_minimum_size'] = '0';
  }
}

/**
 * Checks whether we are currently within the allowed time window for refilling
 * the site reserve.
 */
function hosting_reserve_is_allowed_time_window($time = NULL) {
  if ($time === NULL) {
    $time = time();
  }

  $today = date("D", time());

  $start_time = variable_get('hosting_reserve_refill_window_start', '00:00');
  $end_time = variable_get('hosting_reserve_refill_window_end', '04:00');

  // Date field shenanigans
  if (empty($start_time)) {
    $start_time = strtotime('00:00'); // Midnight "this morning"
  }
  else {
    $start_time = strtotime($start_time);
  }

  if (empty($end_time)) {
    $end_time = strtotime('23:59');
  }
  else {
    $end_time = strtotime($end_time);
  }

  if ($time < $start_time) {
    // Before the start time
    return FALSE;
  }

  if ($time > $end_time) {
    // After the end time
    return FALSE;
  }

  return TRUE;
}

/**
 * Get available clones.
 */
function hosting_reserve_get_clones($pattern = NULL, $include_aliased = FALSE) {
  if ($pattern == NULL) {
    $pattern = '%.' . HOSTING_RESERVE_DEFAULT_CLONE_DOMAIN;
  }

  $result = db_query("SELECT nid FROM node WHERE type = 'site' AND title LIKE '%s' ORDER BY created ASC", $pattern);

  $clones = array();
  while ($obj = db_fetch_object ($result)) {
    $node = node_load($obj->nid);

    if ($node->site_status < 0) {
      continue; // Ignore disabled and deleted sites
    }

    // Exclude 'taken' clones unless otherwise specified
    if (empty($node->aliases) || $include_aliased) {
      $clones[$obj->nid] = $node;
    }
  }

  return $clones;
}

/**
 * Deploys a new site, either from a reserve clone or by cloning the template.
 *
 * This is the main function to call to deploy a new site.
 */
function hosting_reserve_make_site($url) {
  // Get clones
  $clones = hosting_reserve_get_clones();

  if (!empty($clones)) {
    // Deploy first available clone
    $clone = array_shift($clones);
    hosting_reserve_alias_clone($url, $clone);

    return $clone;
  }
  else {
    // If no clones left, clone site as normal
    $error_message = '';
    hosting_saas_clone_site_from_template($url, $error_message);

    return $error_message;
  }
}

function hosting_reserve_alias_clone($url, $clone) {
  // TODO: Validate URL
  $clone->aliases[] = $url;

  node_save($clone); // This triggers a Verify
}

/**
 * Migrate a clone to the permanent URL.
 *
 * The alias is a temporary measure, things can get weird if we don't do this.
 */
function hosting_reserve_migrate_clone($url, $clone) {
  // 1. Remove the alias
  $index = array_search($url, $clone->aliases);

  if ($index === FALSE) {
    // Wrong site
    return FALSE;
  }

  unset($clone->aliases[$index]);
  
  node_save($clone); // This will trigger a Verify.

  // 2. Migrate
  $args = array(
    'new_uri' => $url,
    'new_db_server' => variable_get('hosting_saas_db_server', NULL),
    'target_platform' => variable_get('hosting_saas_target_platform', NULL),
  );

  // Allow other modules to modify the options
  module_invoke_all('hosting_saas_migrate_clone', $url, $args);

  hosting_add_task($clone->nid, 'migrate', $args);

  return TRUE;
}

function hosting_reserve_make_clone(&$error_message = '') {
  $clone_id = variable_get('hosting_reserve_next_clone_id', 1);
  $clone_domain = variable_get('hosting_reserve_clone_domain', HOSTING_RESERVE_DEFAULT_CLONE_DOMAIN);
  $clone_sub_prefix = variable_get('hosting_reserve_clone_sub_prefix', 'hosting-reserve-');

  $url = $clone_sub_prefix . $clone_id . '.' . $clone_domain;

  module_invoke_all('hosting_reserve_new_clone', $url);


  $error_message = '';
  hosting_saas_clone_site_from_template($url, $error_message);

  // TODO: Find something more elegant... Maybe $error_message as reference arg?
  if ($error_message != '') {
    return $error_message;
  }

  // This means the clone_id is not incremented when there is an error.
  $clone_id += 1;
  variable_set('hosting_reserve_next_clone_id', $clone_id);

  return $url;
}

function _hosting_reserve_clean_up_clones() {
  $clones = hosting_reserve_get_clones(NULL, TRUE);

  foreach ($clones as $nid => $clone) {
    // Delete unused clones
    if (empty($clone->aliases)) {
      $time_since_creation = time() - $clone->created;
      $life_time_in_seconds = variable_get('hosting_reserve_clone_life_time', '23') * 60 * 60;

      if ($time_since_creation > $life_time_in_seconds) {
        // Delete site
        hosting_add_task($clone->nid, 'delete');
      }

      // TODO: Delete last backup?
    }
    else {
      // Migrate the ones with aliases
      $url = $clone->aliases[0];

      hosting_reserve_migrate_clone($url, $clone);
    }
  }
}

function hosting_reserve_cron() {
  $clones = hosting_reserve_get_clones();

  if (hosting_reserve_is_allowed_time_window()) {
    _hosting_reserve_clean_up_clones();

    if (count($clones) < variable_get('hosting_reserve_full_size', 10)) {
      $error_message = '';

      // This will fail if a clone is already ongoing, so there's no risk of
      // going over the full reserve size while the task is queued.
      hosting_reserve_make_clone($error_message);

      // TODO: Implement setting to show error messages in the dblog
    }
  }
  else {
    if (count($clones) < variable_get('hosting_reserve_minimum_size', 1)) {
      watchdog('hosting_reserve', '(cron) Reserve depleted, making new clone.');

      hosting_reserve_make_clone();
    }
  }
}

function hosting_reserve_post_hosting_verify_task($task, $data) {
  drush_log('[hosting_reserve] hosting_reserve_post_hosting_verify_task');

  // TODO: Determine if the alias was just added

  // TODO: Implement hook to allow acting on site after it gets aliased
}