Ladies, Gentlemen, and Small Furry Creatures From Alpha Centauri, I present to you: the Docker bug that has been causing all the angst. I got a reliable repro, and verified that only docker-ce
17.11 is impacted. Hopefully, Docker will fix the bug sooner or later, but until then, the recommended workaround is to downgrade Docker to a working version, as follows:
-
Stop and delete all running containers. In addition to this bug, Docker also changed some other things in the way that containers are run, and a downgrade while containers are still running will end in tears. If you’re only running Discourse on your server, you can just stop and delete the container with
docker rm -f app
(your data is safe, and won’t be deleted by this command). If you’re running other containers on the machine as well, you’ll have to figure out what to do. -
Downgrade Docker. Via the magic of the package manager,
apt-get install docker-ce=17.10.0~ce-0~ubuntu
will do the trick. You’ll have to sayy
to the installation, because it’s a downgrade. -
(optional) Make sure Docker doesn’t get automatically upgraded again. That’d really ruin your day, because not only would you have a buggy Docker behind the wheel again, but due to the aforementioned changes in how containers are run, an automated upgrade would likely leave your containers in a kind of limbo state. Not cool.
To make sure you stay on a known-good version, create a file
/etc/apt/preferences.d/docker.pref
with the following contents:Package: docker-ce Pin: version 17.10* Pin-Priority: 9001