Kubelet is responsible for creating symlinks from /var/lib/docker to /var/log
to make fluentd logging collector work.
However without using host's /var/log those links are invisible to fluentd.
This is done on rkt configuration too.
"shell" step doesn't support check mode, which currently leads to failures,
when Ansible is being run in check mode (because Ansible doesn't run command,
assuming that command might have effect, and no "rc" or "output" is registered).
Setting "check_mode: no" allows to run those "shell" commands in check mode
(which is safe, because those shell commands doesn't have side effects).
Vladimir Rutsky