今天在更新22.04之後出現了Docker問題：
cgroups: cgroup mountpoint does not exist: unknown.
$ docker run hello-world
Unable to find image ‘hello-world:latest’ locally
latest: Pulling from library/hello-world
Status: Downloaded newer image for hello-world:latest
docker: Error response from daemon: cgroups: cgroup mountpoint does not exist: unknown.
ERRO[0005] error waiting for container: context canceled
解決方法:
- mkdir /sys/fs/cgroup/systemd
- mount -t cgroup -o none,name=systemd cgroup /sys/fs/cgroup/systemd