"ignoring file '50unattended-upgrades.wcf-dist' in directory '/etc/apt/apt.conmf.d/' as it has an invalid filename extension

Well, did you install those?

apt-get install linux-image-virtual linux-image-extra-virtual

That probably requires a reboot after the install.

Discourse relies on the AUFS filesystem.

@zcalbrecht That’s a lot of stuff. The interesting bits probably scrolled off. Try it with head, eg:

grep docker /var/log*.log | head -20