I did some quick google searches to see if there were any really low-resource, minimal basic heartbeat servers available. I imagine I could do something with a combination of ping, lighttpd, and ssh to get an idea if a) a system is on the net, b) if it's basic services are running and c) if it's accessible but I was wondering if there was anything that was really really small but still basically secure that I could set up, perhaps with a short script to do all or most of the above from a simple restful call?
I'm just wondering what others might have done for this sort of thing. My primary purpose for doing this is that I just set up my growing stable of raspberry pi's on an ESP8266 based wifi relay switch. But I would like to set up the interface so that it will try to see if the system is actually responding in addition to the power being on, and perhaps add features to try safe-shutdowns vs. a hard power off. It would also be nice when switching one back on if my web page could watch for it to become active, perhaps flagging various images or CSS table/div cells to indicate various status conditions (on network, ssh working, etc)
As I say, I have some of my own ideas but before I go redesigning the wheel, I figured I'd check to make sure there isn't something already out there.