mgr/rook: create KubernetesCustomResource class to fetch CRs

This commit creates the KubernetesCustomResource class that inherits from
KubernetesResource to be able to fetch CRs using the CustomObjectsApi
in a cleaner way. It replaces previous try-except pattern.

Signed-off-by: Joseph Sawaya <jsawaya@redhat.com>

diff --git a/src/pybind/mgr/rook/rook_cluster.py b/src/pybind/mgr/rook/rook_cluster.py
index c83d782adc9d931268d04e535a53e71600270620..a7661d952037fd10905a62f4e03dcedd01fd2426 100644 (file)
--- a/src/pybind/mgr/rook/rook_cluster.py
+++ b/src/pybind/mgr/rook/rook_cluster.py
@@ -113,17 +113,10 @@ class KubernetesResource(Generic[T]):
     def _fetch(self) -> str:
         """ Execute the requested api method as a one-off fetch"""
         response = self.api_func(**self.kwargs)
-        # try-except pattern because customObjectApi objects aren't subscriptable
-        try:
-            metadata = response['metadata']
-            self._items = {item['metadata']['name']: item for item in response['items']}
-            log.info('Full fetch of {}. result: {}'.format(self.api_func, len(self._items)))
-            return metadata['resourceVersion']
-        except TypeError:
-            metadata = response.metadata
-            self._items = {item.metadata.name: item for item in response.items}
-            log.info('Full fetch of {}. result: {}'.format(self.api_func, len(self._items)))
-            return metadata.resource_version
+        metadata = response.metadata
+        self._items = {item.metadata.name: item for item in response.items}
+        log.info('Full fetch of {}. result: {}'.format(self.api_func, len(self._items)))
+        return metadata.resource_version
 
     @property
     def items(self) -> Iterable[T]:
@@ -145,6 +138,14 @@ class KubernetesResource(Generic[T]):
 
         return self._items.values()
 
+    def get_item_name(self, item: Any) -> Any:
+        try:
+            return item.metadata.name
+        except AttributeError:
+                    raise AttributeError(
+                        "{} doesn't contain a metadata.name. Unable to track changes".format(
+                            self.api_func)) 
+
     @threaded
     def _watch(self, res_ver: Optional[str]) -> None:
         """ worker thread that runs the kubernetes watch """
@@ -159,14 +160,7 @@ class KubernetesResource(Generic[T]):
                                   **self.kwargs):
                 self.health = ''
                 item = event['object']
-                try:
-                    name = item['metadata']['name']
-                except AttributeError:
-                    raise AttributeError(
-                        "{} doesn't contain a metadata.name. Unable to track changes".format(
-                            self.api_func))
-                except TypeError:
-                    name = item.metadata.name
+                name = self.get_item_name(item)
 
                 log.info('{} event: {}'.format(event['type'], name))
 
@@ -194,6 +188,21 @@ class KubernetesResource(Generic[T]):
             self.exception = e
             raise
 
+class KubernetesCustomResource(KubernetesResource):
+    def _fetch(self) -> str:
+        response = self.api_func(**self.kwargs)
+        metadata = response['metadata']
+        self._items = {item['metadata']['name']: item for item in response['items']}
+        log.info('Full fetch of {}. result: {}'.format(self.api_func, len(self._items)))
+        return metadata['resourceVersion']
+
+    def get_item_name(self, item: Any) -> Any:
+        try:
+            return item['metadata']['name']
+        except AttributeError:
+                    raise AttributeError(
+                        "{} doesn't contain a metadata.name. Unable to track changes".format(
+                            self.api_func))
 
 class RookCluster(object):
     # import of client.CoreV1Api must be optional at import time.