Update default value for api_name in DataVolume and add future warning (RedHatQE#2649)

Author: ema-aka-young

ocp_resources/datavolume.py

@@ -95,7 +95,7 @@ def __init__(
         multus_annotation: str | None = None,
         bind_immediate_annotation: bool | None = None,
         preallocation: bool | None = None,
-        api_name: str | None = "pvc",
+        api_name: str | None = None,
         checkpoints: list[Any] | None = None,
         final_checkpoint: bool | None = None,
         priority_class_name: str | None = None,
@@ -124,7 +124,8 @@ def __init__(
             bind_immediate_annotation (bool, default: None): when WaitForFirstConsumer is set in StorageClass and DV
                 should be bound immediately.
             preallocation (bool, default: None): preallocate disk space.
-            api_name (str, default: "pvc"): api used for DV (e.g., "storage", "pvc").
+            api_name (str | None, default: None): api used for DV (e.g., "storage", "pvc").
+                NOTE: Currently defaults to "pvc" if not specified. Default will change to "storage" in a future release.
             checkpoints (list[Any], default: None): list of DataVolumeCheckpoints for snapshot operations.
             final_checkpoint (bool, default: None): indicates whether the current DataVolumeCheckpoint is the final one.
             priority_class_name (str, default: None): priority class name for the DataVolume pod.
@@ -147,7 +148,17 @@ def __init__(
         self.multus_annotation = multus_annotation
         self.bind_immediate_annotation = bind_immediate_annotation
         self.preallocation = preallocation
-        self.api_name = api_name
+        if api_name is None:
+            warn(
+                "The default 'api_name' will change from 'pvc' to 'storage' in a future release. "
+                "To maintain existing behavior and suppress this warning, "
+                "explicitly set api_name='pvc' in your constructor call.",
+                FutureWarning,
+                stacklevel=2,
+            )
+            self.api_name = "pvc"
+        else:
+            self.api_name = api_name
         self.checkpoints = checkpoints
         self.final_checkpoint = final_checkpoint
         self.priority_class_name = priority_class_name