Replace passing `warnings to exit_json with AnsibleModule.warn` for the few modules (#1033)

SUMMARY
Using exit_json or fail_json for warnings is deprecated in ansible-core>=2.19.0 and will be removed in ansible-core>=2.23.0
Tested with ansible-core 2.19.3 as the latest released version at the time of the start of this PR and with 2.16.0 as the lowest version supported by kubernetes.core 6.x
Resolves: #1031
ISSUE TYPE

Bugfix Pull Request

COMPONENT NAME
k8s_drain
k8s_rollback
k8s_scale
ADDITIONAL INFORMATION
The initial version of this PR covers only the module k8s_drain, with the following commits extended to k8s_rollback
k8s_scale

Reviewed-by: Bianca Henderson <beeankha@gmail.com>
Reviewed-by: Mike Graves <mgraves@redhat.com>
Reviewed-by: Alina Buzachis

plugins/module_utils/copy.py

@@ -278,11 +278,15 @@ class K8SCopyFromPod(K8SCopy):
     def run(self):
         self.files_to_copy = self.list_remote_files()
         if self.files_to_copy == []:
+            # Using warn method instead of passing warnings to exit_json as it is
+            # deprecated in ansible-core>=2.19.0
+            self._module.warn(
+                "No file found from directory '{0}' into remote Pod.".format(
+                    self.remote_path
+                )
+            )
             self.module.exit_json(
                 changed=False,
-                warning="No file found from directory '{0}' into remote Pod.".format(
-                    self.remote_path
-                ),
             )
         self.copy()
 

plugins/modules/k8s_drain.py

@@ -441,7 +441,8 @@ class K8sDrainAnsible(object):
                     warnings.append(warn)
             result.append("{0} Pod(s) deleted from node.".format(number_pod))
         if warnings:
-            return dict(result=" ".join(result), warnings=warnings)
+            for warning in warnings:
+                self._module.warn(warning)
         return dict(result=" ".join(result))
 
     def patch_node(self, unschedulable):

plugins/modules/k8s_rollback.py

@@ -168,7 +168,9 @@ def perform_action(svc, resource):
             module.params["kind"],
             resource["metadata"]["name"],
         )
-        result = {"changed": False, "warnings": [warn]}
+        if warn:
+            module.warn(warn)
+        result = {"changed": False}
         return result
 
     if module.params["kind"] == "Deployment":

plugins/modules/k8s_scale.py

@@ -243,10 +243,12 @@ def execute_module(client, module):
             module.fail_json(msg=error, **return_attributes)
 
     def _continue_or_exit(warn):
+        if warn:
+            module.warn(warn)
         if multiple_scale:
-            return_attributes["results"].append({"warning": warn, "changed": False})
+            return_attributes["results"].append({"changed": False})
         else:
-            module.exit_json(warning=warn, **return_attributes)
+            module.exit_json(**return_attributes)
 
     for existing in existing_items:
         if kind.lower() == "job":