Merge remote-tracking branch 'upstream/master'

inventory/sample/group_vars/k8s-cluster.yml

...ontroller/ingress_nginx/templates/ingress-nginx-cm.yml.j2

...ess_nginx/templates/ingress-nginx-tcp-servicecs-cm.yml.j2

...ess_nginx/templates/ingress-nginx-udp-servicecs-cm.yml.j2

roles/kubernetes/master/defaults/main.yml

roles/kubernetes/master/tasks/encrypt-at-rest.yml

roles/kubernetes/master/tasks/main.yml

roles/kubernetes/master/templates/kubeadm-config.yaml.j2

...tes/master/templates/manifests/kube-apiserver.manifest.j2

roles/kubernetes/master/templates/secrets_encryption.yaml.j2

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

tests/files/gce_centos7-flannel-addons.yml