Merge pull request #2462 from woopstar/coredns-patch

docs/dns-stack.md

docs/vars.md

inventory/sample/group_vars/k8s-cluster.yml

roles/docker/tasks/set_facts_dns.yml

roles/download/defaults/main.yml

roles/kubernetes-apps/ansible/defaults/main.yml

roles/kubernetes-apps/ansible/tasks/cleanup_dns.yml

roles/kubernetes-apps/ansible/tasks/coredns.yml

roles/kubernetes-apps/ansible/tasks/kubedns.yml

roles/kubernetes-apps/ansible/tasks/main.yml

...ernetes-apps/ansible/templates/coredns-clusterrole.yml.j2

...-apps/ansible/templates/coredns-clusterrolebinding.yml.j2

...s/kubernetes-apps/ansible/templates/coredns-config.yml.j2

...bernetes-apps/ansible/templates/coredns-deployment.yml.j2

roles/kubernetes-apps/ansible/templates/coredns-sa.yml.j2

roles/kubernetes-apps/ansible/templates/coredns-svc.yml.j2

roles/kubernetes/node/templates/kubelet.kubeadm.env.j2

roles/kubernetes/node/templates/kubelet.standard.env.j2

roles/kubernetes/preinstall/tasks/set_resolv_facts.yml

roles/kubespray-defaults/defaults/main.yaml