Officially deprecate rollback for introspection rules

This was designed to clean up action effects, but proved too confusing.
We should recommend using explicit clean up action instead.

Change-Id: Ia414979956cc0cbd5ed040831c49dba18671f86d

CONTRIBUTING.rst

@@ -268,10 +268,6 @@ Writing a Plugin
 
   The following methods and attributes may also be overridden:
 
-  ``rollback(node_info,params,**)``
-      called to clean up when conditions were not met.
-      Default implementation does nothing.
-
   ``validate(params,**)``
       called to validate parameters provided during actions creating.
       Default implementation requires keys listed in ``REQUIRED_PARAMS`` (and

doc/source/usage.rst

@@ -49,8 +49,6 @@ them automatically after running all processing hooks.
 
 A rule consists of conditions to check, and actions to run. If conditions
 evaluate to true on the introspection data, then actions are run on a node.
-All actions have "rollback actions" associated with them, which are run when
-conditions evaluate to false. This way we can safely rerun introspection.
 
 Available conditions and actions are defined by plugins, and can be extended,
 see :ref:`contributing_link` for details. See :ref:`api` for specific calls

ironic_inspector/plugins/base.py

@@ -16,13 +16,15 @@
 import abc
 
 from oslo_config import cfg
+from oslo_log import log
 import six
 import stevedore
 
-from ironic_inspector.common.i18n import _
+from ironic_inspector.common.i18n import _, _LW
 
 
 CONF = cfg.CONF
+LOG = log.getLogger(__name__)
 
 
 @six.add_metaclass(abc.ABCMeta)
@@ -195,4 +197,10 @@ def rule_actions_manager():
         _ACTIONS_MGR = stevedore.ExtensionManager(
             'ironic_inspector.rules.actions',
             invoke_on_load=True)
+        for act in _ACTIONS_MGR:
+            # a trick to detect if function was overriden
+            if "rollback" in act.obj.__class__.__dict__:
+                LOG.warning(_LW('Defining "rollback" for introspection rules '
+                                'actions is deprecated (action "%s")'),
+                            act.name)
     return _ACTIONS_MGR

ironic_inspector/plugins/example.py

@@ -37,6 +37,3 @@ def example_not_found_hook(introspection_data, **kwargs):
 class ExampleRuleAction(base.RuleActionPlugin):  # pragma: no cover
     def apply(self, node_info, params, **kwargs):
         LOG.debug('apply action to %s: %s', node_info.uuid, params)
-
-    def rollback(self, node_info, params, **kwargs):
-        LOG.debug('rollback action to %s: %s', node_info.uuid, params)

releasenotes/notes/deprecate-rollback-dea95ac515d3189b.yaml

@@ -0,0 +1,4 @@
+---
+deprecations:
+  - The rollback actions for introspection rules are deprecated. No in-tree
+    actions are using them, 3rdpart should stop using them as soon as possible.