Lookup blockdev D-Bus properties without raising not found exception

If the pool object path is not on the D-Bus, stratisd will not even have
a field for that item in the GetManagedObjects result and will raise an
exception. Do not allow the exception to propagate in this case, but
catch it and return the unknown string.

Signed-off-by: mulhern <[email protected]>

Author: mulkieran

src/stratis_cli/_actions/_physical.py

@@ -21,6 +21,9 @@
 # isort: THIRDPARTY
 from justbytes import Range
 
+# isort: FIRSTPARTY
+from dbus_client_gen import DbusClientMissingPropertyError
+
 from .._stratisd_constants import BlockDevTiers
 from ._connection import get_object
 from ._constants import TOP_OBJECT
@@ -79,6 +82,16 @@ def list_devices(namespace: Namespace):  # pylint: disable=too-many-locals
             ).search(managed_objects)
         )
 
+        def pool_name_lookup(modev) -> str:
+            """
+            Look up a name for a pool. Return place holder if the modev
+            has no pool attribute.
+            """
+            try:
+                return path_to_name.get(modev.Pool(), TABLE_UNKNOWN_STRING)
+            except DbusClientMissingPropertyError:  # pragma: no cover
+                return TABLE_UNKNOWN_STRING
+
         def paths(modev):
             """
             Return <physical_path> (<metadata_path>) if they are different,
@@ -91,8 +104,11 @@ def paths(modev):
             :returns: the string to print
             :rtype: str
             """
-            metadata_path = modev.Devnode()
-            physical_path = modev.PhysicalPath()
+            try:
+                metadata_path = modev.Devnode()
+                physical_path = modev.PhysicalPath()
+            except DbusClientMissingPropertyError:  # pragma: no cover
+                return TABLE_UNKNOWN_STRING
 
             return (
                 metadata_path
@@ -105,32 +121,49 @@ def size(modev):
             Return in-use size (observed size) if they are different, otherwise
             just in-use size.
             """
-            in_use_size = Range(modev.TotalPhysicalSize())
-            observed_size = get_property(modev.NewPhysicalSize(), Range, in_use_size)
+            try:
+                in_use_size = Range(modev.TotalPhysicalSize())
+                observed_size = get_property(
+                    modev.NewPhysicalSize(), Range, in_use_size
+                )
+            except DbusClientMissingPropertyError:  # pragma: no cover
+                return TABLE_UNKNOWN_STRING
+
             return (
                 f"{in_use_size}"
                 if in_use_size == observed_size
                 else f"{in_use_size} ({observed_size})"
             )
 
-        def tier_str(value):
+        def tier_str(modev) -> str:
             """
             String representation of a tier.
             """
             try:
-                return str(BlockDevTiers(value))
+                return str(BlockDevTiers(modev.Tier()))
             except ValueError:  # pragma: no cover
                 return TABLE_UNKNOWN_STRING
+            except DbusClientMissingPropertyError:  # pragma: no cover
+                return TABLE_UNKNOWN_STRING
 
         format_uuid = get_uuid_formatter(namespace.unhyphenated_uuids)
 
+        def uuid_str(modev) -> str:
+            """
+            String representation of UUID.
+            """
+            try:
+                return format_uuid(modev.Uuid())
+            except DbusClientMissingPropertyError:  # pragma: no cover
+                return TABLE_UNKNOWN_STRING
+
         tables = [
             [
-                path_to_name.get(modev.Pool(), TABLE_UNKNOWN_STRING),
+                pool_name_lookup(modev),
                 paths(modev),
                 size(modev),
-                tier_str(modev.Tier()),
-                format_uuid(modev.Uuid()),
+                tier_str(modev),
+                uuid_str(modev),
             ]
             for modev in modevs
         ]