[fix-compat] Tolerate non-string defaults in String type3.1.0

Cinder folks found an issue where StrOpt had a default
value set to an integer. We were tolerating this before
so we should continue to do so with a warning.

Change-Id: I0af75f1a7102454d9285ab8df9d19242fada2325

2 files changed, 19 insertions, 0 deletions

diff --git a/oslo_config/tests/test_generator.py b/oslo_config/tests/test_generator.py
index f2875ea..1f64ebe 100644
--- a/oslo_config/tests/test_generator.py
+++ b/oslo_config/tests/test_generator.py
@@ -137,6 +137,9 @@ class GeneratorTestCase(base.BaseTestCase):
                                                     default=['1', '2', '3'],
                                                     sample_default=['5', '6'],
                                                     help='multiple strings'),
+        'string_type_with_bad_default': cfg.Opt('string_type_with_bad_default',
+                                                help='string with bad default',
+                                                default=4096),
         'custom_type': cfg.Opt('custom_type',
                                help='custom help',
                                type=type('string')),
@@ -619,6 +622,18 @@ class GeneratorTestCase(base.BaseTestCase):
 # custom help (unknown value)
 #custom_type = <None>
 ''')),
+        ('string_type_with_bad_default',
+         dict(opts=[('test', [(None,
+                               [opts['string_type_with_bad_default']])])],
+              expected='''[DEFAULT]
+
+#
+# From test
+#
+
+# string with bad default (string value)
+#string_type_with_bad_default = 4096
+''')),
     ]
 
     output_file_scenarios = [
diff --git a/oslo_config/types.py b/oslo_config/types.py
index c098bfa..a126681 100644
--- a/oslo_config/types.py
+++ b/oslo_config/types.py
@@ -21,6 +21,7 @@ Use these classes as values for the `type` argument to
 """
 import operator
 import re
+import warnings
 
 import abc
 import netaddr
@@ -46,6 +47,9 @@ class ConfigType(object):
         return [default_str]
 
     def quote_trailing_and_leading_space(self, str_val):
+        if not isinstance(str_val, six.string_types):
+            warnings.warn('converting \'%s\' to a string' % str_val)
+            str_val = six.text_type(str_val)
         if str_val.strip() != str_val:
             return '"%s"' % str_val
         return str_val