Debain cron help accessing a URL

Question

The documentation says that I need to:

If your hosting account is on LINUX/UNIX system you can setup a CRON job to point to this URL http://yourUrlToThisScript.com/cron.php?cron=do&d=31

Although this is the only information they give on how to set up the cron. I know the script is working correctly because when I access the URL by a browser I receive the emails.

1. I have looked at a couple of examples and tried reading the manual: Executing PHP files and have come up with: */1 * * * * /usr/bin/php -q /var/www/website/public/domain-manager/cron.php cron=do&d=31 >/dev/nul

Although this is not working and I don't receive any emails or errors?

2. How can I protect this file cron.php so that it can't be executed from a browser? Maybe something like this answer although for a single file instead of a directory.

Answer 1

There is a slight difference of how you call a PHP script and especially how it will process the given parameters. The documentation is about a HTTP GET request and you are doing a command line call of the PHP script.

Example of a HTTP GET request executed via command line:

wget -q -O  - "http://localhost/domain-manager/cron.php?cron=do&d=31"

Example of executing a PHP script via command line:

php -f /var/www/website/public/domain-manager/cron.php cron=do d=31

The main difference is how PHP will get the parameters. For the HTTP request PHP will use an interface to Apache or whatever web server you are using and fetch parameters in a $_GET array. For the command line call PHP must use the $argv array.

If the documentation requires a HTTP call I would use it, even if the command line call will be better for performance reasons and does not have such limitations.

Recommendation for your crontab:

*/2 * * * * wget -q -O  - "http://localhost/domain-manager/cron.php?cron=do&d=31" > /dev/null 2>&1

Recommendation for protecting this file from external request: Content of /var/www/website/public/domain-manager/.htaccess (in same directory)

<files cron.php>
order deny,allow
deny from all
allow from localhost
</files>