Properly convert non-string filters to expected string format

Signed-off-by: Joffrey F <joffrey@docker.com>

docker/utils/utils.py

@@ -386,7 +386,10 @@ def convert_filters(filters):
             v = 'true' if v else 'false'
         if not isinstance(v, list):
             v = [v, ]
-        result[k] = v
+        result[k] = [
+            str(item) if not isinstance(item, six.string_types) else item
+            for item in v
+        ]
     return json.dumps(result)
 
 

tests/unit/utils_test.py

@@ -457,8 +457,8 @@ class UtilsTest(unittest.TestCase):
         tests = [
             ({'dangling': True}, '{"dangling": ["true"]}'),
             ({'dangling': "true"}, '{"dangling": ["true"]}'),
-            ({'exited': 0}, '{"exited": [0]}'),
-            ({'exited': [0, 1]}, '{"exited": [0, 1]}'),
+            ({'exited': 0}, '{"exited": ["0"]}'),
+            ({'exited': [0, 1]}, '{"exited": ["0", "1"]}'),
         ]
 
         for filters, expected in tests: