Infrastructure

The Kubernetes cluster is gone. One mini PC runs the whole house now: four network segments, a solar inverter Home Assistant can act on, and a guard that shuts the servers down before the battery does.

I segmented my network, wrote tests to prove it, and watched the tests pass while measuring nothing at all. Then the same disease turned up in my home automation, and left a freezer switched off for thirteen hours in a house full of green ticks.

A Growatt inverter, a Raspberry Pi running Solar Assistant, and Home Assistant on Proxmox. Bridging them took an MQTT broker, a form that silently discarded everything I typed, and a decision to keep the link read-only. Then it stopped watching the house and started switching it off.

The rules that seal my IoT segment, in the order they have to be written, and the two that look redundant until you understand what they are for.

A 5kW hybrid inverter and a 5.12 kWh battery, bought to ride out power cuts. Three years later the panels went up and it quietly became the primary supply, with the grid as the fallback.