Raspberry Pi client/server setup for OctoPrint

This shouldn't be that difficult (jinxed myself).  I think the OS matters more than the hardware, so I'll look at that first.  For now I'll use a pair of Raspberry Pi 3s (Model B+).  I don't plan to use the WiFi.

Operating System:

I'm going to make my life difficult and enable SELinux.  That rules out Raspbian, its kernel doesn't include the hooks required.

Because I was looking for reverse ssh solutions, I ended up getting a lot of search hits for kali - a debian distribution for black hats and therefore used by crackers too.

Since the OctoPi image is also Raspbian, I'll have to install OctoPrint myself.  How hard could it be?

These instructions assume everything other than the Pi is done on a mac.

Erase the SD card, using Disk Utility. Choose “MS-DOS (FAT)”, which is FAT32. Partition it “Master Boot Record” if it isn’t already. Note the device name. chop off the last letter/number to determine the device path, e.g. disk3s1 has the device path: /dev/disk3 and I’ll use that below.

After downloading the OS image, copy to SD using:

sudo dd if=Desktop/kali-linux-2018.4a-rpi3-nexmon-64.img of=/dev/disk3

This takes a while, 28 minutes in my case. The SD will re-mount when the copy is done. Eject after it remounts.