Changing behavior of ImagePolicies, more...

ImagePolicies() called fail_json() when the caller asked for a policy_name that did not exist on the controller.

During initial work on dcnm_image_policy module, we need this to return None instead.  Hence, changing the behavior.

This does not require any other changes to dcnm_image_upgrade, other than modifying one of the unit tests to expect the new behavior.

plugins/module_utils/image_mgmt/image_policies.py

@@ -119,10 +119,10 @@ def _get(self, item):
             self.module.fail_json(msg)
 
         if self.policy_name not in self.properties["response_data"]:
-            msg = f"{self.class_name}.{self.method_name}: "
-            msg += f"policy_name {self.policy_name} is not defined "
-            msg += "on the controller."
-            self.module.fail_json(msg)
+            return None
+
+        if item == "policy":
+            return self.properties["response_data"][self.policy_name]
 
         if item not in self.properties["response_data"][self.policy_name]:
             msg = f"{self.class_name}.{self.method_name}: "
@@ -195,6 +195,15 @@ def policy_name(self):
     def policy_name(self, value):
         self.properties["policy_name"] = value
 
+    @property
+    def policy(self):
+        """
+        Return the policy data of the policy matching self.policy_name,
+        if it exists.
+        Return None otherwise
+        """
+        return self._get("policy")
+
     @property
     def policy_type(self):
         """

tests/unit/modules/dcnm/dcnm_image_upgrade/test_image_upgrade_image_policies.py

@@ -227,10 +227,11 @@ def test_image_mgmt_image_policies_00024(monkeypatch, image_policies) -> None:
     """
     Function
     - refresh
+    - policy_name
 
     Test
-    - fail_json() is called if response does not contain policy_name.
-    - i.e. image policy with name FOO has not yet been created on the controller.
+    - instance.policy_name is set to a policy that does not exist on the controller.
+    - instance.policy returns None
 
     Endpoint
     - /appcenter/cisco/ndfc/api/v1/imagemanagement/rest/policymgnt/policies
@@ -243,16 +244,19 @@ def mock_dcnm_send_image_policies(*args) -> Dict[str, Any]:
 
     monkeypatch.setattr(DCNM_SEND_IMAGE_POLICIES, mock_dcnm_send_image_policies)
 
-    image_policies.refresh()
-    image_policies.policy_name = "FOO"
+    with does_not_raise():
+        instance = image_policies
+        instance.refresh()
+        image_policies.policy_name = "FOO"
 
-    match = "ImagePolicies._get: "
-    match += "policy_name FOO is not defined on the controller."
+    assert image_policies.policy is None
+    # match = "ImagePolicies._get: "
+    # match += "policy_name FOO is not defined on the controller."
 
-    instance = image_policies
-    with pytest.raises(AnsibleFailJson, match=match):
-        if instance.policy_type == "PLATFORM":
-            pass
+    # instance = image_policies
+    # with pytest.raises(AnsibleFailJson, match=match):
+    #     if instance.policy_type == "PLATFORM":
+    #         pass
 
 
 def test_image_mgmt_image_policies_00025(monkeypatch, image_policies) -> None: