Enable kubeadm etcd mode (#4818)

* Enable kubeadm etcd mode

Uses cert commands from kubeadm experimental control plane to
enable non-master nodes to obtain etcd certs.

Related story: PROD-29434

Change-Id: Idafa1d223e5c6ceadf819b6f9c06adf4c4f74178

* Add validation checks and exclude calico kdd mode

Change-Id: Ic234f5e71261d33191376e70d438f9f6d35f358c

* Move etcd mode test to ubuntu flannel HA job

Change-Id: I9af6fd80a1bbb1692ab10d6da095eb368f6bc732

* rename etcd_mode to etcd_kubeadm_enabled

Change-Id: Ib196d6c8a52f48cae370b026f7687ff9ca69c172

roles/kubernetes/master/tasks/kubeadm-secondary-experimental.yml

@@ -43,6 +43,10 @@
     kubeadm_certificate_key: "{{ hostvars[groups['kube-master'][0]]['kubeadm_upload_cert'].stdout_lines[-1] | trim }}"
   when: kubeadm_certificate_key is undefined
 
+- name: check already run
+  debug:
+    msg: "{{ kubeadm_already_run.stat.exists }}"
+
 - name: Joining control plane node to the cluster.
   command: >-
     {{ bin_dir }}/kubeadm join
@@ -52,9 +56,11 @@
     --certificate-key={{ kubeadm_certificate_key }}
     {% endif %}
   register: kubeadm_join_control_plane
+  retries: 3
+  until: kubeadm_join_control_plane is succeeded
   when:
     - inventory_hostname != groups['kube-master']|first
-    - not kubeadm_already_run.stat.exists
+    - kubeadm_already_run is not defined or not kubeadm_already_run.stat.exists
   environment:
     PATH: "{{ bin_dir }}:{{ ansible_env.PATH }}"