Running a PHP script forever with Supervisor

Let’s say you want to run a script forever (like a job queuing system that needs to constantly listen to incoming jobs) you could just start the process with a php my-script.php and be done with it (HAHA jk) but then how do you make sure it always run? And what if you want to monitor it?

I saw in the past people relying on crontabs (@reboot) and doing a screen of their scripts. the problem with this approach is that your script might die for whatever reason and won’t restart.

I stumbled upon a nice process control system called Supervisor which will make sure your scripts run and will even give you a nice web interface :)

Install Supervisor

sudo apt-get install supervisor

The above command will install the supervisor service in your /etc/ that you can start, stop, restart, force-reload, status, force-stop.

If you look at the /etc/supervisor/supervisord.conf config file, you’ll see that supervisor includes config files in /etc/supervisor/conf.d/*.conf. Let’s create one for our forever running php script.

sudo vi /etc/supervisor/conf.d/are-we-there-yet.conf

# and paste the below
[program:are_we_there_yet]
command=php /var/www/areWeThereYet.php
numprocs=1
directory=/tmp
autostart=true
autorestart=true
startsecs=5
startretries=10
redirect_stderr=false
stdout_logfile=/var/www/are-we-there-yet.out.log
stdout_capture_maxbytes=1MB
stderr_logfile=/var/www/are-we-there-yet.error.log
stderr_capture_maxbytes=1MB

And now let’s create our dummy php script file:

<?php

while (true) {
    echo 'Are we there yet??'.PHP_EOL;
    sleep(5);
}
?>

I know - awesome script right?

So let’s save all that and restart our supervisor:

sudo service supervisor restart

# check if supervisor is running
ps -auxf | grep supervisor

# check if your php script is running
ps -auxf | grep php

You should see the python process running (/usr/bin/python /usr/bin/supervisord -c /etc/supervisor/supervisord.conf) and your awesome (haha) script (\_ php /var/www/areWeThereYet.php) also running in the background, populating your two logs defined in the supervisor config.

Web interface of logs

sudo vi /etc/supervisor/supervisord.conf

# Add this bit at the end:
[inet_http_server]
port=9001
username = YourUsernameHere
password = YourPasswordHere

Restart supervisor and now if you have a http server (restart it as well) you can go on http://localhost:9001 fill in username/password and access the supervisord web interface.

Supervisor web interface