Thought I’d just post this in case it helps anyone else. I have been trying lots of images and kernels on my arm machine and ran in to similar issues with installing docker. This time it was seeming to install but the brewblox installation was failing and docker error messages were saying it couldn’t connect to the docker daemon. There seem to be lots of reasons that can happen and the standard logs didn’t reveal why. After a lot 
of investigation I eventually discovered another log file making reference to being unable to make a network bridge and referring to ipv6 which I discovered was by default being disabled on my machine. I was then either able to enable ipv6 at boot (or disable it in docker) and either way I had a working docker and brewblox. I’m sure there must be tens of reasons for a failed install of docker but this was my experience.
That’s a good point. We’ve been explicitly enabling IPv6 in Docker to fix a bug, but this was done with the assumption that the host has IPv6 enabled if not necessarily active.
I’ll tinker with some combination of settings to achieve the desired goals of fixing the bug where all containers restart if any container restarts, but without editing host network configuration.