Make Tentacles auto configure the disable flag on shutdown.
When the tentacle service shuts down, the polling tentacle would change the machine.isdisabled = true. When the service starts it would set the isdisabled=false. this allows cloud based infrastructure to dynamically turn off machines without having the deployments fail because the machine is turned off.
Tom Hall commented
This would be really helpful in an autoscaling environment. I'm currently installing & registering the Octopus Tentacle when a new server is launched, and then requesting a deploy. When the server is automatically terminated (which at some point, that will happen) it'd be good if there were some sort of option to mark the server as offline, or even a configurable rule that you could enable for an environment to say "Hey, I'm a cloud environment and when servers go offline for more than 30mins, remove them".
Eric Hexter commented
I have written an application to disable and enable on system startup, I found that I also needed to look up the lasted version deployed the the environments the tentacle is registered in and kick off a deployment to the machine to make sure it has the latest version. This allows me to utilize Azure Auto Scale features and make sure we always have the correct versions deployed.