Upgraded subcloud upgrade ansible failure with error " vars/k8s-v1.18.1 directory does not exist"

[Ramesh kumar Sivanandam]

Brief Description
------------------
Subcloud upgrade failed with error "vars/k8s-v1.18.1 directory does not exist"
Prior to subcloud upgrade to stx7.0 it was upgraded from stx5.0 to stx6.0 and kube upgraded to v1.21.8.

Severity
--------
Critical: subcloud upgrade on the upgraded system was failing

Steps to Reproduce
------------------
1. Install stx5.0
2. Upgrade to stx6.0
3. Upgrde kubversion to v1.21.8

Expected Behavior
-----------------
no errors on subcloud

Actual Behavior
---------------
Ansible failure error
ansible_included_var_files: []
message: vars/k8s-v1.18.1 directory does not exist
FAILED TASK: TASK [bootstrap/prepare-env : Read in kubernetes versioned configuration parameters] Sunday 12 ovember 2023 05:25:15 +0000 (0:00:00.019)

Reproducibility
---------------
100% reproducible. Tested twice seen twice.

System Configuration
--------------------
Distributed Cloud

Timestamp/Logs
--------------

TASK [bootstrap/prepare-env : Read in kubernetes versioned configuration parameters] ***
Sunday 12 November 2023 05:25:15 +0000 (0:00:00.019) 0:00:33.370 *******
fatal: [subcloud1]: FAILED! => changed=false
ansible_facts: {}
ansible_included_var_files: []
message: vars/k8s-v1.18.1 directory does not exist

PLAY RECAP *********************************************************************
subcloud1 : ok=104 changed=33 unreachable=0 failed=1 skipped=88 rescued=0 ignored=0

Test Activity
-------------
Regression

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/ansible-playbooks/+/900963

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/ansible-playbooks/+/900963
Committed: https://opendev.org/starlingx/ansible-playbooks/commit/d69c34c118146f8318afb9fdde22f1ee35990ce4
Submitter: "Zuul (22348)"
Branch: master

commit d69c34c118146f8318afb9fdde22f1ee35990ce4
Author: Ramesh Kumar Sivanandam <email address hidden>
Date: Tue Nov 14 19:09:46 2023 -0500

    Fetch the correct Kubernetes version during platform upgrade

    When perform the platform upgrade after the kubernetes version
    upgrade, it fails to fetch the correct Kubernetes version.

    This change obtains the kubernetes version by extracting
    kubeadm_version field of the kube_cmd_versions table in sysinv
    database dump, which is contained in the upgrade_data_*.tgz
    backup file during the platform upgrade.

    This change is identical to code in the file
    playbookconfig/src/playbooks/roles/bootstrap/prepare-env/tasks/main.yml
    which retrieves the kubernetes version from the sysinv database file.

    Test Plan:
    PASS: Install stx5.0, Platform upgrade to stx6.0 and K8s upgrade
          1.18 -> 1.19 -> 1.20 -> 1.21. Platform upgrade to stx.7.0

    Closes-Bug: 2043518

    Change-Id: I5be349db962b7ce4ee0cbd9215dc79b63d6cf168
    Signed-off-by: Ramesh Kumar Sivanandam <email address hidden>