Run php script as daemon process

Question

I need to run a php script as daemon process (wait for instructions and do stuff). cron job will not do it for me because actions need to be taken as soon as instruction arr

Answer 1

With new systemd you can create a service.

You must create a file or a symlink in /etc/systemd/system/, eg. myphpdaemon.service and place content like this one, myphpdaemon will be the name of the service:

[Unit]
Description=My PHP Daemon Service
#May your script needs MySQL or other services to run, eg. MySQL Memcached
Requires=mysqld.service memcached.service 
After=mysqld.service memcached.service

[Service]
User=root
Type=simple
TimeoutSec=0
PIDFile=/var/run/myphpdaemon.pid
ExecStart=/usr/bin/php -f /srv/www/myphpdaemon.php arg1 arg2> /dev/null 2>/dev/null
#ExecStop=/bin/kill -HUP $MAINPID #It's the default you can change whats happens on stop command
#ExecReload=/bin/kill -HUP $MAINPID
KillMode=process

Restart=on-failure
RestartSec=42s

StandardOutput=null #If you don't want to make toms of logs you can set it null if you sent a file or some other options it will send all php output to this one.
StandardError=/var/log/myphpdaemon.log
[Install]
WantedBy=default.target

You will be able to start, get status, restart and stop the services using the command

systemctl myphpdaemon

The PHP script should have a kind of "loop" to continue running.

Working example:

[Unit]
Description=PHP APP Sync Service
Requires=mysqld.service memcached.service
After=mysqld.service memcached.service

[Service]
User=root
Type=simple
TimeoutSec=0
PIDFile=/var/run/php_app_sync.pid
ExecStart=/bin/sh -c '/usr/bin/php -f /var/www/app/private/server/cron/app_sync.php  2>&1 > /var/log/app_sync.log'
KillMode=mixed

Restart=on-failure
RestartSec=42s

[Install]
WantedBy=default.target

If your PHP routine should be executed once in a cycle (like a diggest) you may should use a shell or bash script to be invoked into systemd service file instead of PHP directly, for example:

#!/usr/bin/env bash
script_path="/app/services/"

while [ : ]
do
#    clear
    php -f "$script_path"${1}".php" fixedparameter ${2}  > /dev/null 2>/dev/null
    sleep 1
done

If you chose these option you should change the KillMode to mixed to processes, bash(main) and PHP(child) be killed.

ExecStart=/app/phpservice/runner.sh phpfile parameter  > /dev/null 2>/dev/null
KillMode=process

This method also is effective if you're facing a memory leak.

Note: Every time that you change your "myphpdaemon.service" you must run `systemctl daemon-reload', but do worry if you not do, it will be alerted when is needed.