Ouput a placeholder instead of the auth_token

As the name of the get_logging_values suggests, that function will
get entries from the context for logging purposes. For this, we
shouldn't need the auth_token since it might potentially leak
in the logs.

This filters out the auth_token by setting it as '***' by
default.

Change-Id: I2b245c1665c3587be3c476b803122788d186e5d5

oslo_context/context.py

@@ -353,6 +353,13 @@ class RequestContext(object):
                   'user_domain_name': self.user_domain_name,
                   'project_domain_name': self.project_domain_name}
         values.update(self.to_dict())
+        if self.auth_token:
+            # NOTE(jaosorior): Gotta obfuscate the token since this dict is
+            # meant for logging and we shouldn't leak it.
+            values['auth_token'] = '***'
+        else:
+            values['auth_token'] = None
+
         return values
 
     @property

oslo_context/tests/test_context.py

@@ -486,6 +486,7 @@ class ContextTest(test_base.BaseTestCase):
 
         d = ctx.get_logging_values()
         self.assertIn('auth_token', d)
+        self.assertEqual(d['auth_token'], '***')
         self.assertIn('user', d)
         self.assertIn('tenant', d)
         self.assertIn('domain', d)

releasenotes/notes/dont-leak-auth-token-fb7075316cf87b7c.yaml

@@ -0,0 +1,7 @@
+---
+security:
+  - |
+    The ``get_logging_values`` function no longer outputs the auth_token, but
+    instead leaves it as ``***`` instead. As the name suggests, this function is
+    meant for logging, and letting the auth_token there might leak sensitive
+    data.