How to disable automatic scheduled Puppet runs that occur every 30 minutes?

"Attempt one" should have worked. If it was already running you have to stop it yourself. This just prevents future instances from daemonizing. If I am missing something, please clarify why this didn't work. You can also chkconfig puppet off && service puppet stop on Red Hat and derivatives.

You need to ensure that the puppet agent is not starting as a service. Commands like systemctl, or chkconfig are your friend here (e.g. systemctl disable puppet or chkconfig puppet off). Not sure about most distros.

Then you should also make sure that the agent is stopped. E.g. systemctl stop puppet or service stop puppet.

You can also just use puppet to accomplish the above:

puppet apply <(echo "service { puppet: ensure => false, enable => false }")

If it still doesn't work, pkill puppet for good measure, then try again, if it still doesn't work - reboot.

Are you looking for a command like:

puppet agent --disable