* Switch to kubeadm deployment mode

Discuss:https://github.com/kubernetes-incubator/kubespray/issues/3301

* Add non-kubeadm upgrage to kubeadm cluster

* Add resource-container flag to kube-proxy manifest

* add resourceContainer: "" to kubeadm kube-proxy configs

Due to suboptimal external loadbalancer configs, the LoadBalancer
might point to a downed kube-apiserver that is not set up yet.

* warning on meta flush_handlers

* avoid rm

* avoid "Module remote_tmp /root/.ansible/tmp did not exist and was created with a mode of 0700, this may cause issues when running as another user. To avoid this, create the remote_tmp dir with the correct permissions manually" warning on subsequent tasks using blockinfile

* is match

* failed

* version_compare

* succeeded

* skipped

* success

* version_compare becomes version since ansible 2.5

* ansible minimal version updated in doc and spec

* last version_compare

* [jjo] add kube-router support

Fixes cloudnativelabs/kube-router#147.

* add kube-router as another network_plugin choice
* support most used kube-router flags via
  `kube_router_foo` vars as other plugins
* implement replacing kube-proxy (--run-service-proxy=true) via
  `kube_proxy_mode: none`, verified in a _non kubeadm_enabled_
  install, should also work for recent kubeadm releases via
  `skipKubeProxyInstall: true` config

* [jjo] address PR#3339 review from @woopstar

* add busybox image used by kube-router to downloads

* fix busybox download groups key

* rework kubeadm_enabled + kube_router_run_service_proxy

- verify it working ok w/the kubeadm_enabled and
  kube_router_run_service_proxy true or false

- introduce `kube_proxy_remove` fact, to decouple logic
  from kube_proxy_mode (which affects kubeadm configmap
  settings, thus no-good to ab-use it to 'none')

* improve kube-router.md re: kubeadm_enabled and kube_router_run_service_proxy

* address @woopstar latest review

* add inventory/sample/group_vars/k8s-cluster/k8s-net-kube-router.yml

* fix kube_router_run_service_proxy conditional for kube-proxy removal

* fix kube_proxy_remove fact (w/ |bool), add some needed kube-proxy tags on my and existing changes

* update kube-router tolerations for 1.12 compatibility

* add PriorityClass to kube-router DaemonSet

* Upgrade kubernetes to v1.12.0

Use kubeadm v1alpha3 config

* Upgrade coredns and etcd

* Upgrage docker to 18.06

* Better fix for openstack cinder zone issue[1][2]
using ignore-volume-az option[3].
[1]: https://github.com/kubernetes-incubator/kubespray/pull/2155
[2]: https://github.com/kubernetes-incubator/kubespray/pull/2346
[3]: https://github.com/kubernetes/kubernetes/pull/53523

* Remove kube-scheduler-policy.yaml

* Changes to assign pod priority to kube components.

* Removed the boolean flag pod_priority_assignment

* Created new priorityclass k8s-cluster-critical

* Created new priorityclass k8s-cluster-critical

* Fixed the trailing spaces

* Fixed the trailing spaces

* Added kube version check while creating Priority Class k8s-cluster-critical

* Moved k8s-cluster-critical.yml

* Moved k8s-cluster-critical.yml to kube_config_dir

* Support for AWS cloud-config

* Update docs

* Fix version incompatibilities

* Do not use shorthand `default`

* Add new cloud config variable, roleArn

Move kube_kubeadm_controller_extra_args to controllerManagerExtraArgs section. It was placed in controllerManagerExtraVolumes

https://kubernetes.io/blog/2018/07/11/dynamic-kubelet-configuration/

ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version

remove empty when line

ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version

force kubeadm upgrade due to failure without --force flag

ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version

added nodeSelector to have compatibility with hybrid cluster with win nodes, also fix for download with missing container type

fixes in syntax and LF for newline in files

fix on yamllint check

ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version

some cleanup for innecesary lines

remove conditions for nodeselector