Fix Trident playbook

The trident playbook was using a role which used an undefined
variable named 'kubernetes_version'.
We fix this by adding a role that will determine the
'kubernetes_version' before using it.

Testing done:

Ran install_netapp_backend.yml playbook and it passed successfully

Closes-Bug: #1942318
Change-Id: Ie71b3b50a7667d2eaae7a002325b060d6130c26a
Signed-off-by: Mihnea Saracin <Mihnea.Saracin@windriver.com>

playbookconfig/src/playbooks/install_netapp_backend.yml

@@ -13,6 +13,7 @@
   # Main play
   roles:
     - { role: common/prepare-env }
+    - { role: common/get-kube-version, become: yes }
     - { role: roles/common/push-docker-images, become: yes }
     - { role: roles/k8s-storage-backends/snapshot-controller, become: yes }
     - { role: roles/k8s-storage-backends/netapp, become: yes }

playbookconfig/src/playbooks/roles/common/get-kube-version/tasks/main.yml

@@ -0,0 +1,17 @@
+---
+#
+# Copyright (c) 2021 Wind River Systems, Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+- block:
+  - name: Get kubernetes_version from the DB
+    shell: echo "select kubeadm_version from kube_cmd_versions" | psql -qAt -d sysinv
+    register: kube_ver_select_result
+    become_user: postgres
+
+  - name: Set kubernetes_version to the value from DB
+    set_fact:
+      kubernetes_version: "{{ kube_ver_select_result.stdout_lines[0] }}"
+
+  when: kubernetes_version is not defined