Support non-dict mappings in mask_dict_password

mask_dict_password doesn't actually have a dependency on the dict
type specifically. It can work on any subclass of collections.Mapping.
This changes the isinstance check to reflect that and adds a unit
test using a collections.Mapping subclass.

Change-Id: I28781acf027b9b34f8274196db5dd4d2a9adc9ba
Closes-Bug: 1804528

1 files changed, 4 insertions, 3 deletions

diff --git a/oslo_utils/strutils.py b/oslo_utils/strutils.py
index ebcc104..d7b104d 100644
--- a/oslo_utils/strutils.py
+++ b/oslo_utils/strutils.py
@@ -17,6 +17,7 @@
 System-level utilities and helper functions.
 """
 
+import collections
 import math
 import re
 import unicodedata
@@ -390,12 +391,12 @@ def mask_dict_password(dictionary, secret="***"):  # nosec
 
     """
 
-    if not isinstance(dictionary, dict):
-        raise TypeError("Expected a dictionary, got %s instead."
+    if not isinstance(dictionary, collections.Mapping):
+        raise TypeError("Expected a Mapping, got %s instead."
                         % type(dictionary))
     out = {}
     for k, v in dictionary.items():
-        if isinstance(v, dict):
+        if isinstance(v, collections.Mapping):
             out[k] = mask_dict_password(v, secret=secret)
             continue
         # NOTE(jlvillal): Check to see if anything in the dictionary 'key'