ElegantOTA VS Tasmota

As u/__deeetz__ pointed out, the esp32 already had a good OTA mechanism, and there are some libraries that simplify the whole process - probably one of the more popular ones is ElegantOTA: https://github.com/ayushsharma82/ElegantOTA If I understand what you're doing correctly, you'll really have just 2 layers, not 3 - one being your application (which effectively has the Kernel/OS compiled in), and then your scripting/LUA component. Technically the ESP32 also has a bootloader portion, but it's pretty uncommon to need to modify that in any way, so I would highly recommend against doing that. As far as dealing with the LUA scripts - you can easily download and run those - you'll store them into NV ram, and I believe the current recommended format is LittleFS. Keep in mind that on a normal ESP32 configured to do OTA updates there's 4MB of storage, 2x 1.8MB for the two bootable images, and ~200k for the file system (in this case LittleFS). There are also other boards which come with more flash memory, like the new S3R8 has 16MB of flash, so your OTA partitions stay about the same in most cases, but you now have ~12MB of storage, which I suspect would be way beyond anything you'd need for storing LUA.

I'm looking for a small, thin example of the ESP32 hosting a webserver to accept firmware update files for OTA updates. There's a handful of Arduino libraries that do exactly this (e.g. https://github.com/ayushsharma82/ElegantOTA) but I haven't come across anything clean that's just built around IDF.

All of my office devices are connected to Sonoff S31 smart plugs, flashed with Tasmota on their own locked-down VLAN, and can be controlled via voice, Alexa, Tasker automation on my Android, NFC tags at my office door and various scripts triggered via my StreamDeck (on Linux). This all works fantastic, and I can turn on or off my devices, including my printer, when I start or end my day at work.

The best alternative firmware example for true IOT devices is Tasmota [1]. Erase manufacturer firmware for every ESP devices the day after purchase to avoid those careless manufacturer firmwares.

[1] https://tasmota.github.io/docs/

The ESP8266 based Sonoff S31 and ESP32 based Switchbot plugs, both flashed with either Tasmota or ESPHome, are my go-to options for US WiFi smart plugs with power monitoring.

And if you want to turn your ESP8266 into a standalone appliance, with a web interface and directly editable config that doesn't need a build step, Tasmota is another great option.

https://tasmota.github.io/docs/