(note this is nothing to do with RouterOS/Mikrotik integration)
Has anyone used Mikrotik hardware to run HA, in a container? I’m interested what hardware models have been tried, and whether this is a viable alternative to Pi hardware.
What is inside a typical machine? I looked up the Microtik site, but there are dozens on offer.
Also what OS can one run on them?
They run the gamut, and you can, in fact, install RouterOS (Mikrotik’s operating system) on x86 hardware.
There’s not really a “typical machine,” I suppose. You can get a $25 device with a 650MHz CPU and 64MB of RAM, or a $3,500 router with a 72 Core CPU and 16 of RAM.
The problem I see, as a total novice, granted, is that Mikrotik devices have CPU architectures that are catered toward routing and switching, and might not be appropriate for things like HA.
I am thinking something pretty minimal in the Mikrotik range: https://mikrotik.com/product/RB750Gr3
Do you think this kind of CPU (mMIPS) would be impractical to run something like HA. The reason I asked is that RouterOS supports MQTT, and therefore you wonder - where do you stop 
Having cheap, redundant, passively cooled hardware is obviously a plus - but would it have enough grunt or would you advocate for a Pi instead…
I don’t think HA is compiled for MIPS is it?
@nickrout when I say Mikrotik, I was really referring to RouterOS on Mikrotik hardware, even though yes you can run others (OpenWRT I assum) - sorry for not being clear
I have seen threads on this forum about running in openwrt, try and search