Small update — I split the custom plugins out of this project into their own repo, for anyone who just wants the plugins without pulling in the whole install script:
https://github.com/acebmxer/xo-plugins
Same deal as always — use at your own risk, review the code before running it on anything that matters. The two plugins in there are also still shipped inside this install script's Custom Plugins menu, kept in sync automatically — this repo just exists for people who don't want the rest of the project.
xo-server-nanokvm
This one's probably the more useful of the two for a lot of people. If you've got a host with no iLO/DRAC/IPMI — most consumer/prosumer boards, a lot of homelab gear — and you've wired up a Sipeed NanoKVM to the power header, this plugin lets Xen Orchestra power that host back on through the NanoKVM's own API. Same interface the NanoKVM web UI itself uses to press the button, just done from XO.
On its own it doesn't decide when to turn a host on, it just gives XO a way to do it. Pairs with the other plugin below for that, or you could call it from your own automation if you wanted.
Worth knowing: it can only press the button, it has no way to know if the host is actually on or off, so it only handles power-on. Powering off goes through XO's normal shutdown, which is a clean OS shutdown and evacuates VMs first — no reason to route that through the NanoKVM.
Setup is a config entry per host: label, the NanoKVM's URL, a login, and which XO host it's wired to. Recommend making it a dedicated user-role account on the NanoKVM rather than admin — that role already has power/reset access without giving the plugin anything to storage/network settings on the KVM itself.
xo-server-host-power-manager
This is the one that actually decides when to act. Point it at an "extra" host in the pool and give it CPU and/or memory thresholds — when the rest of the pool is under pressure it powers that host on, and once things calm down for a while it powers it back off. Power-on can go through XO's built-in methods or through the NanoKVM plugin above, your choice per rule.
Powering off always goes through XO's own host shutdown — it evacuates the running VMs first, and if HA is on and doesn't have room to cover it, XAPI just refuses and the plugin backs off and tries again later rather than forcing anything.
It's deliberately quick to scale up and slow to scale down (needs both CPU and memory comfortable for a full cooldown period before it'll power a host off) so it's not flapping a host on and off over a short spike.
Both have a Test button in their config page that actually tells you something useful, unlike XO's own generic "test plugin" popup — check journalctl -u xo-server right after clicking it to see what it found.
As always, happy to hear feedback or find out I've broken something.
