Linux PHP Daemon

Better than a crontab!

Many a time have my development team needed to “cronify” a PHP script for completing business logic quietly behind the scenes. Once the command-line (CLI) version of the application was complete they would start creating and managing a crontab. This practice is NO MORE for my development teams!

Enter a better way of “cronifying” or better stated “daemonizing” a PHP CLI application. I have created a sample of “daemonizing” a PHP CLI application at https://github.com/donbstringham/php-daemon. This example is based on an article by Bobby Allen. Follow the directions below and now you have a linux system daemon that is actually a PHP command-line application.

• php-daemon.conf - Place in the directory /etc/init. On line 9 in use the full path to the PHP file. It is very important to use fully qualified paths in both the Upstart configuration file as well as any script files that Upstart daemonizes.
• php-daemon.php - Place in any directory you want. Remember it to use fully qualified paths.

Use the commands below to start, stop and view the status of the new linux daemon:

sudo status php-daemon

sudo start php-daemon

sudo stop php-daemon

NOTE: While implementing this on CENTOS/RHEL boxes a few minor changes where needed to get it run in a stable manner. The main change was to run the daemons under the root user. Other changes are listed below in the code:

/etc/init/php-daemon.conf

start on startup
stop on shutdown
respawn

script
    echo "DEBUG: `set`" > /root/php-daemon-env.log

    /root/php-daemon
end script

/home/stringhamdb/php-daemon

#!/usr/bin/php
<?php
// The worker will execute every X seconds:
$seconds = 1;

// We work out the micro seconds ready to be used by the 'usleep' function.
$micro = $seconds * 1000000;

while (true) {
  // This is the code you want to loop during the service...
  $fh = fopen('/root/php-daemon.log', 'a') or die('Can not open file');
  $stringData = 'File updated at: '.time().PHP_EOL;
  fwrite($fh, $stringData);
  fclose($fh);
  // Now before we 'cycle' again, we'll sleep for a bit...
  usleep($micro);
}