When download_run_once with download_localhost is used, docker is
expected to be running on the delegate localhost. That may be not
the case for a non localhost delegate, which is the kube-master
otherwise. Then the dnsmasq role, had it been invoked early before
deployment starts, would fail because of the missing docker dependency.
* Fix that dependency on docker and do not pre download dnsmasq image
for the dnsmasq role, if download_localhost is disabled.
* Remove become: false for docker CLI invocation because that's not
the common pattern to allow users access docker CLI w/o sudo.
* Fix opt bin path hack for localhost delegate to ignore errors when
it fails with "sudo password required" otherwise.
* Describe download_run_once with download_localhost use case in docs
as well.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
