Process Control Tools

Requirements

• posix and pcntl extensions
• PHP5.4+ (Uses modern syntax)
• Basic knowledge of PHP on the command line

Daemon

A really useful tool with a very boring name. Daemonize your PHP scripts with two lines of code.

Usage

Code:

<?php
// Preferred:
require 'vendor/autoload.php'; // composer
declare(ticks=1);
(new Firehed\ProcessControl\Daemon)
    ->setUser('sites')
    ->setPidFileLocation('/var/run/gearman-manager2.pid')
    ->setStdoutFileLocation(sys_get_temp_dir().'/my.log')
    ->setStdErrFileLocation('/dev/null')
    ->setProcessName(basename(__FILE__).' master process')
    ->autoRun();
// The rest of your original script

CLI:

php yourscript.php {status|start|stop|restart|reload|kill}

Yes, it's that simple.

Actions

• Status: Check the status of the process. Returns:
  • 0 if running
  • 1 if dead but pidfile is hanging around
  • 3 if stopped
• Start: Start the daemon
• Stop: Stop the daemon gracefully via SIGTERM
• Restart: Stop (if running) and start
• Reload: Send SIGUSR1 to daemon (you need to implement a reload function, see below)
• Kill: Kill the daemon via SIGKILL (kill -9)

Options

• setProcessName($string): Set the process name as it will appear in utilities such as top. This is only supported under PHP5.5+.
• setPidFileLocation($path): Specify the location of the pid file. This file stores the process id when the daemon is running, and goes away when the daemon stops.
• setStdoutFileLocation($path): File where anything that would have been written to STDOUT (echo, print, etc) goes.
• setStdErrFileLocation($path): File where anything that would have been written to STDERR goes. It appears that display_errors no longer writes to STDERR after daemonizing, so setting this to /dev/null is pretty safe.
• setUser($system_user): If you want to have the process run as a lower-security user, specify the username here. This is especially helpful if you start the daemon on system with chkconfig and /etc/init.d, since those run as root.

To come later(?):

• Verbose output
• Synchronous mode (do not daemonize for debugging)
• Log file configuration

Useful tips

• STDOUT (echo, print) is redirected to the log file.
• The "reload" command won't do anything without installing a handler for SIGUSR1. Examples are due shortly.

Known Issues

• STDERR doesn't appear to go anywhere, despite opening a logfile for it.
• The script can't set up "reload" bindings automatically. This is a PHP limitation: "The declare construct can also be used in the global scope, affecting all code following it (however if the file with declare was included then it does not affect the parent file)". http://docs.php.net/manual/en/control-structures.declare.php