So, this upgrade both succeeded and failed.
What I mean by that is that, after upgrading:
I was unable to log in. My SSH key was, apparently, gone. I had to edit the linux boot settings to specify
Upon using auto login, I realized that all my containers were gone, which I could quickly confirm by checking that /var/lib/docker was now empty.
That’s when I realized that I was now in a completely new, virgin environment.
Good news is that I am using grub, so I created an additional entry with linux and initrd pointing to their 0.5.0 versions. After booting using this profile, I was able to see all my containers again. Nothing was lost.
So, how does this happen? And what can I do to fix this situation? Obviously, I would like to run a more recent version.