Fix the suppress of policy deprecation warnings

oslo.policy log the deprected policy warning while loading the
policy rule. Flag to suppress the warning was set after load_rule()
was called.

Moving the setting of suppress_deprecation_warnings flag before
load_rule method is called.

Closes-Bug: #1858652

Change-Id: I3f30df8f0fdf76d763ee4770af074a2f4f400ee8

nova/policy.py

@@ -49,7 +49,8 @@ def reset():
         _ENFORCER = None
 
 
-def init(policy_file=None, rules=None, default_rule=None, use_conf=True):
+def init(policy_file=None, rules=None, default_rule=None, use_conf=True,
+         suppress_deprecation_warnings=False):
     """Init an Enforcer class.
 
        :param policy_file: Custom policy file to use, if none is specified,
@@ -59,6 +60,8 @@ def init(policy_file=None, rules=None, default_rule=None, use_conf=True):
        :param default_rule: Default rule to use, CONF.default_rule will
                             be used if none is specified.
        :param use_conf: Whether to load rules from config file.
+       :param suppress_deprecation_warnings: Whether to suppress the
+                                             deprecation warnings.
     """
 
     global _ENFORCER
@@ -70,6 +73,8 @@ def init(policy_file=None, rules=None, default_rule=None, use_conf=True):
                                     rules=rules,
                                     default_rule=default_rule,
                                     use_conf=use_conf)
+        if suppress_deprecation_warnings:
+            _ENFORCER.suppress_deprecation_warnings = True
         register_rules(_ENFORCER)
         _ENFORCER.load_rules()
 

nova/tests/unit/policy_fixture.py

@@ -50,11 +50,10 @@ class RealPolicyFixture(fixtures.Fixture):
         self._prepare_policy()
         CONF.set_override('policy_file', self.policy_file, group='oslo_policy')
         nova.policy.reset()
-        nova.policy.init()
         # NOTE(gmann): Logging all the deprecation warning for every unit
-        # test will overflow the log files and leads to error. Suppress
-        # the deprecation warning for tests only.
-        nova.policy._ENFORCER.suppress_deprecation_warnings = True
+        # test will overflow the log files. Suppress the deprecation warnings
+        # for tests.
+        nova.policy.init(suppress_deprecation_warnings=True)
         self.addCleanup(nova.policy.reset)
 
     def set_rules(self, rules, overwrite=True):