Comment by h-c-c

Check out MQTT and Adafruit.io in particular. The cool thing about MQTT is that your device is reachable behind NAT. I'm doing pretty much exactly what you describe here with this IOT-lamp project.

https://github.com/h-c-c/IOT-LAMP

I set up a 'util' feed for system commands and have implemented a shutdown routine so far. I send my lamp commands with Google Assistant through IFTTT.