Lookup blockdev D-Bus properties without raising not found exception

src/stratis_cli/_actions/_formatting.py

@@ -17,13 +17,17 @@
 
 # isort: STDLIB
 import sys
+from functools import wraps
 from typing import Any, Callable, List, Optional
 from uuid import UUID
 
 # isort: THIRDPARTY
 from dbus import Struct
 from wcwidth import wcswidth
 
+# isort: FIRSTPARTY
+from dbus_client_gen import DbusClientMissingPropertyError
+
 # placeholder for tables where a desired value was not obtained from stratisd
 # when the value should be supported.
 TABLE_FAILURE_STRING = "FAILURE"
@@ -160,3 +164,23 @@ def get_uuid_formatter(unhyphenated: bool) -> Callable:
     return (
         (lambda u: UUID(str(u)).hex) if unhyphenated else (lambda u: str(UUID(str(u))))
     )
+
+
+def catch_missing_property(
+    prop_to_str: Callable[[Any], Any], default: Any
+) -> Callable[[Any], Any]:
+    """
+    Return a function to just return a default if a property is missing.
+    """
+
+    @wraps(prop_to_str)
+    def inner(mo: Any) -> str:
+        """
+        Catch the exception and return a default
+        """
+        try:
+            return prop_to_str(mo)
+        except DbusClientMissingPropertyError:  # pragma: no cover
+            return default
+
+    return inner

src/stratis_cli/_actions/_list_filesystem.py

@@ -28,7 +28,9 @@
 from ._constants import TOP_OBJECT
 from ._formatting import (
     TABLE_FAILURE_STRING,
+    TABLE_UNKNOWN_STRING,
     TOTAL_USED_FREE,
+    catch_missing_property,
     get_property,
     print_table,
 )
@@ -152,17 +154,37 @@ def filesystem_size_quartet(
             )
             return f"{triple_str} / {limit}"
 
+        pool_name_func = catch_missing_property(
+            lambda mo: self.pool_object_path_to_pool_name.get(
+                mo.Pool(), TABLE_UNKNOWN_STRING
+            ),
+            TABLE_UNKNOWN_STRING,
+        )
+        name_func = catch_missing_property(
+            lambda mofs: mofs.Name(), TABLE_UNKNOWN_STRING
+        )
+        size_func = catch_missing_property(
+            lambda mofs: filesystem_size_quartet(
+                Range(mofs.Size()),
+                get_property(mofs.Used(), Range, None),
+                get_property(mofs.SizeLimit(), Range, None),
+            ),
+            TABLE_UNKNOWN_STRING,
+        )
+        devnode_func = catch_missing_property(
+            lambda mofs: mofs.Devnode(), TABLE_UNKNOWN_STRING
+        )
+        uuid_func = catch_missing_property(
+            lambda mofs: self.uuid_formatter(mofs.Uuid()), TABLE_UNKNOWN_STRING
+        )
+
         tables = [
             (
-                self.pool_object_path_to_pool_name[mofilesystem.Pool()],
-                mofilesystem.Name(),
-                filesystem_size_quartet(
-                    Range(mofilesystem.Size()),
-                    get_property(mofilesystem.Used(), Range, None),
-                    get_property(mofilesystem.SizeLimit(), Range, None),
-                ),
-                mofilesystem.Devnode(),
-                self.uuid_formatter(mofilesystem.Uuid()),
+                pool_name_func(mofilesystem),
+                name_func(mofilesystem),
+                size_func(mofilesystem),
+                devnode_func(mofilesystem),
+                uuid_func(mofilesystem),
             )
             for mofilesystem in self.filesystems_with_props
         ]