EC2 Shutdown when no users are logged in

[pathawks]

After the EC2 instance has processed all messages in the queue, it should shutdown. However, there are times when I need to login manually to perform some maintenance and I do not want the EC2 instance to shutdown while I am logged in.

I have never gotten this to work reliably. Either the instance will shutdown whether or not I am logged in, or it will never automatically shutdown and I will need to manually reboot the instance to get it to start processing messages from the queue again.

If anybody knows of a reliable way to check if there are any interactive sessions, that would really help.

Utterson/aws/ec2/boot

Lines 13 to 16 in d24ee3e

	if (( USERS = 0 )); then
	wall "Shutting down."
	shutdown -h now
	fi