* Fix DNS loop when resolvconf_mode is set to host_resolvconf

* Make sure upstream_dns_servers is defined when using resolvconf_mode == 'host_resolvconf'

* Only set upstream dns servers on KubeDNS and CoreDNS if they are defined

* Only set upstream dns servers on KubeDNS and CoreDNS if they are defined

Labels from role (node-role.k8s.io/node) and labels from inventory are merged into node-labels parameter in kubelet

Addition of the .creds extension to the credentials files generated by password lookup in order for Ansible not to consider them as inventory files with inventory_ignore_extensions set accordingly (#2446)

Added CoreDNS to downloads

Updated with labels. Should now work without RBAC too

Fix DNS settings on hosts

Rename CoreDNS service from kube-dns to coredns

Add rotate based on http://edgeofsanity.net/rant/2017/12/20/systemd-resolved-is-broken.html

Updated docs with CoreDNS info

Added labels and fixed minor settings from official yaml file: https://github.com/kubernetes/kubernetes/blob/release-1.9/cluster/addons/dns/coredns.yaml.sed

Added a secondary deployment and secondary service ip. This is to mitigate dns timeouts and create high resitency for failures. See discussion at 'https://github.com/coreos/coreos-kubernetes/issues/641#issuecomment-281174806'

Set dns list correct. Thanks to @whereismyjetpack

Only download KubeDNS or CoreDNS if selected

Move dns cleanup to its own file and import tasks based on dns mode

Fix install of KubeDNS when dnsmask_kubedns mode is selected

Add new dns option coredns_dual for dual stack deployment. Added variable to configure replicas deployed. Updated docs for dual stack deployment. Removed rotate option in resolv.conf.

Run DNS manifests for CoreDNS and KubeDNS

Set skydns servers on dual stack deployment

Use only one template for CoreDNS dual deployment

Set correct cluster ip for the dns server

In 1.8, the Node authorization mode should be listed first to
allow kubelet to access secrets. This seems to only impact
environments with cloudprovider enabled.

* Rename dns_server to dnsmasq_dns_server so that it includes role prefix
as the var name is generic and conflicts when integrating with existing ansible automation.
*  Enable selinux state to be configurable with new var preinstall_selinux_state

* Set no_proxy to all local ips

* Use proxy settings on all necessary tasks

* Upgrade to kubernetes v1.8.0

hyperkube no longer contains rsync, so now use cp

* Enable node authorization mode

* change kube-proxy cert group name

This follows pull request #1677, adding the cgroup-driver
autodetection also for kubeadm way of deploying.

Info about this and the possibility to override is added to the docs.

Updates based on feedback

Simplify checks for file exists

remove invalid char

Review feedback. Use regular systemd file.

Add template for docker systemd atomic

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

kubelet lost the ability to load kernel modules.  This
puts that back by adding the lib/modules mount to kubelet.

The new variable kubelet_load_modules can be set to true
to enable this item.  It is OFF by default.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>