[ci_nmstate] Check if kubeconfig file exists

The ci_nmstate role was failing during adoption deploy-infra jobs when
cifmw_openshift_kubeconfig was defined but the file didn't exist yet.

Root cause: ci-framework-jobs' adoption-uni-job-base uses variable_files_dirs
to scan all YAML files in the scenario directory, including 05-tests.yaml
which sets cifmw_openshift_kubeconfig. This has been the case since adoption
jobs were introduced in October 2024.

However, during the deploy-infra phase (before deploy-ocp), the OCP cluster
and kubeconfig file don't exist yet. The issue was likely exposed by PR openstack-k8s-operators#3471
which changed how ansible_user_dir is evaluated, affecting how/when the
kubeconfig path gets resolved.

Fix: Add "cifmw_openshift_kubeconfig is exists" check to tasks that use the
kubeconfig. The existing code already handles the skipped task gracefully
via default([]) safeguards, treating all hosts as "unmanaged" when no k8s
cluster is available (which is correct for infra creation).

Fixes: OSPCIX-1122
Related: openstack-k8s-operators#3471
Assisted-By: Claude Code/claude-4.5-sonnet
Signed-off-by: Harald Jensås <[email protected]>

Author: hjensas

roles/ci_nmstate/tasks/main.yml

@@ -54,7 +54,9 @@
     label: "{{ item }}"
 
 - name: Get k8s nodes
-  when: cifmw_openshift_kubeconfig is defined
+  when:
+    - cifmw_openshift_kubeconfig is defined
+    - cifmw_openshift_kubeconfig is exists
   kubernetes.core.k8s_info:
     kubeconfig: "{{ cifmw_openshift_kubeconfig }}"
     api_key: "{{ cifmw_openshift_token | default(omit)}}"
@@ -93,6 +95,7 @@
 - name: Provision k8s workers with nmstate
   when:
     - cifmw_openshift_kubeconfig is defined
+    - cifmw_openshift_kubeconfig is exists
     - >-
       _cifmw_ci_nmstate_configs | dict2items |
       selectattr('key', 'in', _cifmw_ci_nmstate_k8s_hosts) |