Daemon API

This project has been moved to 7.x-2.x of the Drush Daemon Project.

This module is meant to provide a simple means of creating a robust command-line-driven, fully bootstrapped PHP Daemon. It uses the PHP-Daemon (https://github.com/shaneharter/PHP-Daemon) Library to create the Daemon (via the Libraries API) in order to not re-invent the wheel ;-).

Features

• Provides a Drush interface to start/stop your Daemon.
• Your daemon starts in the background and is detached from the current terminal.
• Daemon is fully bootstrapped so you can use any Drupal function when designing your task/job.
• Easy, two-step process to help you develop a custom bootstrapped daemon with Drush support.
• Add advanced functionality and override default functionality easily due to the class-based structure of the Daemon API.
• Lock Files, Automatic restart (8hrs default) and Built-in Signal Handling & Event Logging are only a few of the features provided by the PHP-Daemon Library making this a fully featured & robust Daemon.

Custom Daemon Development

Using this API to create your own daemon takes only two steps:
1. Register your Daemon with the Daemon API:
This is done by implementing hook_daemon_api_info() in your .module file.

/**
 * Implements hook_daemon_api_info().
 * Registers our Daemon with the Daemon API
 */
function mymodule_daemon_api_info() {
  $daemon = array();

  // This is an example daemon which just sleeps for random amounts of time.
  $daemon['example_daemon'] = array(
    // The machine name of the daemon (same as key above).
    'machine_name' => 'example_daemon',
    // A human-readable name for your daemon.
    'name' => 'Example Daemon',
    // This module (ie: the module implementing the daemon).
    'module' => 'daemon_api',
    // The class extending DrupalDaemon and implementing your daemon-specific
    // functionality. This class should be in a [classname].inc file in your
    // modules base directory.
    'class' => 'DaemonApiExampleDaemon',
    // OPTIONAL: Define this if your module doesn't follow the rule mentioned
    // in the above comment. The name and path to the file containing the
    // daemon class assuming your module folder as the root.
    'class_file' => 'DaemonApiExampleDaemon.inc',
  );

  return $daemon;
}

2. Implement a DaemonApiDaemon class:
Simply create a class as shown in the code snippet below. This should be located in a [classname].inc file in your module directory and only needs to implement one method executeTask().

/**
 * My Custom Daemon
 */
class MyModuleDaemon extends DaemonApiDaemon {

  /**
   * Implements DrupalDaemon::executeTask().
   *
   * This gets executed once per loop iteration.
   */
  protected function execute_task() {

      // Do all of your task/job logic here.
      // This is a fully Drupal Bootstrapped environment meaning all your module
      // functions and really any function available to your site.
      
      // Log any output
      $this->log("Tell my users what I'm doing");
  }
}

Finally run your daemon on the command-line using drush daemon start [daemon machine name]. That really is it!

Custom Daemon Usage

Start Daemon

• drush daemon start [daemon-machine-name]

Stop Daemon

• drush daemon stop [daemon-machine-name]

Check the Status

• drush daemon status [daemon-machine-name]

Show the Log

• List the last 10 lines of the log file:
  drush daemon show-log [daemon-machine-name]
• List the last N lines of the log file:
  drush daemon show-log [daemon-machine-name] --num_lines=N

Requirements

• Libraries API
• PHP-Daemon Library version 2.0
• Drush 5.x

Installation

1. Install all required modules as per their instructions.
2. Install this module as you would normally install a contributed drupal
   module. See:https://drupal.org/documentation/install/modules-themes/modules-7
   for further information.
3. Download the PHP-Daemon Library and extract it in your sites/all/libraries
   directory. The folder must be named "PHP-Daemon".

Future Development

1. Report Page (Administration > Reports > Daemons) showing the current status of all registered daemons and linking to log files so you can monitor your daemon through the web interface!