Fix for callback plugins on Python3 when a module returns dictionary keys that aren't strings

This fixes one of the problems reported in https://github.com/ansible/ansible/issues/49343

Upstream Python3 bug for the json traceback:
https://bugs.python.org/issue25457

and PR that may fix it:
https://github.com/python/cpython/pull/8011

changelogs/fragments/fix-callbacks-mixed-keys.yaml

@@ -0,0 +1,4 @@
+---
+bugfixes:
+  - Fix for callback plugins on Python3 when a module returns non-string field
+    names in its results.  (https://github.com/ansible/ansible/issues/49343)

lib/ansible/plugins/callback/__init__.py

@@ -29,12 +29,21 @@ from copy import deepcopy
 
 from ansible import constants as C
 from ansible.module_utils.common._collections_compat import MutableMapping
+from ansible.module_utils.six import PY3
+from ansible.module_utils._text import to_text
 from ansible.parsing.ajson import AnsibleJSONEncoder
 from ansible.plugins import AnsiblePlugin, get_plugin_class
 from ansible.utils.color import stringc
 from ansible.utils.display import Display
 from ansible.vars.clean import strip_internal_keys
 
+if PY3:
+    # OrderedDict is needed for a backwards compat shim on Python3.x only
+    # https://github.com/ansible/ansible/pull/49512
+    from collections import OrderedDict
+else:
+    OrderedDict = None
+
 global_display = Display()
 
 try:
@@ -119,7 +128,18 @@ class CallbackBase(AnsiblePlugin):
         if 'exception' in abridged_result:
             del abridged_result['exception']
 
-        return json.dumps(abridged_result, cls=AnsibleJSONEncoder, indent=indent, ensure_ascii=False, sort_keys=sort_keys)
+        try:
+            jsonified_results = json.dumps(abridged_result, cls=AnsibleJSONEncoder, indent=indent, ensure_ascii=False, sort_keys=sort_keys)
+        except TypeError:
+            # Python3 bug: throws an exception when keys are non-homogenous types:
+            # https://bugs.python.org/issue25457
+            # sort into an OrderedDict and then json.dumps() that instead
+            if not OrderedDict:
+                raise
+            jsonified_results = json.dumps(OrderedDict(sorted(abridged_result.items(), key=to_text)),
+                                           cls=AnsibleJSONEncoder, indent=indent,
+                                           ensure_ascii=False, sort_keys=False)
+        return jsonified_results
 
     def _handle_warnings(self, res):
         ''' display warnings, if enabled and any exist in the result '''

test/units/plugins/callback/test_callback.py

@@ -19,6 +19,7 @@
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
+import json
 import re
 import textwrap
 import types
@@ -26,6 +27,7 @@ import types
 from units.compat import unittest
 from units.compat.mock import patch, mock_open, MagicMock
 
+import pytest
 
 from ansible.plugins.callback import CallbackBase
 
@@ -133,7 +135,7 @@ class TestCallbackResults(unittest.TestCase):
         self.assertEqual(result, expected_result)
 
 
-class TestCallbackDumpResults(unittest.TestCase):
+class TestCallbackDumpResults(object):
     def test_internal_keys(self):
         cb = CallbackBase()
         result = {'item': 'some_item',
@@ -144,26 +146,26 @@ class TestCallbackDumpResults(unittest.TestCase):
                   'bad_dict_key': {'_ansible_internal_blah': 'SENTINEL'},
                   'changed': True}
         json_out = cb._dump_results(result)
-        self.assertFalse('"_ansible_' in json_out)
-        self.assertFalse('SENTINEL' in json_out)
-        self.assertTrue('LEFTIN' in json_out)
+        assert '"_ansible_' not in json_out
+        assert 'SENTINEL' not in json_out
+        assert 'LEFTIN' in json_out
 
     def test_exception(self):
         cb = CallbackBase()
         result = {'item': 'some_item LEFTIN',
                   'exception': ['frame1', 'SENTINEL']}
         json_out = cb._dump_results(result)
-        self.assertFalse('SENTINEL' in json_out)
-        self.assertFalse('exception' in json_out)
-        self.assertTrue('LEFTIN' in json_out)
+        assert 'SENTINEL' not in json_out
+        assert 'exception' not in json_out
+        assert 'LEFTIN' in json_out
 
     def test_verbose(self):
         cb = CallbackBase()
         result = {'item': 'some_item LEFTIN',
                   '_ansible_verbose_always': 'chicane'}
         json_out = cb._dump_results(result)
-        self.assertFalse('SENTINEL' in json_out)
-        self.assertTrue('LEFTIN' in json_out)
+        assert 'SENTINEL' not in json_out
+        assert 'LEFTIN' in json_out
 
     def test_diff(self):
         cb = CallbackBase()
@@ -171,8 +173,20 @@ class TestCallbackDumpResults(unittest.TestCase):
                   'diff': ['remove stuff', 'added LEFTIN'],
                   '_ansible_verbose_always': 'chicane'}
         json_out = cb._dump_results(result)
-        self.assertFalse('SENTINEL' in json_out)
-        self.assertTrue('LEFTIN' in json_out)
+        assert 'SENTINEL' not in json_out
+        assert 'LEFTIN' in json_out
+
+    def test_mixed_keys(self):
+        cb = CallbackBase()
+        result = {3: 'pi',
+                  'tau': 6}
+        json_out = cb._dump_results(result)
+        round_trip_result = json.loads(json_out)
+        assert len(round_trip_result) == 2
+        assert '3' in round_trip_result
+        assert 'tau' in round_trip_result
+        assert round_trip_result['3'] == 'pi'
+        assert round_trip_result['tau'] == 6
 
 
 class TestCallbackDiff(unittest.TestCase):