Deprecate CONF.monkey_patch

This option, along with monkey_patch_modules, is
arguably worse than hooks since it doesn't even
rely on having in-tree code. It's super legacy,
not tested, not supported and is a barrier to
interoperability, so we should deprecate it for
removal.

This also allows us to deprecate the default_publisher_id
option which is used for the legacy notify_decorator
which is only used if specified with the monkey_patch_modules
option, which is also deprecated here.

Also removed the nova.api.ec2.cloud mention from the
config option help text for monkey_patch_modules
since that isn't valid in nova anymore.

Change-Id: Id793ac2c5cdc5dc473f95eac53b77617a1e389da

nova/conf/base.py

@@ -63,6 +63,12 @@ entry.
     cfg.BoolOpt(
         'monkey_patch',
         default=False,
+        deprecated_for_removal=True,
+        deprecated_since='17.0.0',
+        deprecated_reason="""
+Monkey patching nova is not tested, not supported, and is a barrier
+for interoperability.
+""",
         help="""
 Determine if monkey patching should be applied.
 
@@ -74,6 +80,12 @@ Related options:
     cfg.ListOpt(
         'monkey_patch_modules',
         default=['nova.compute.api:nova.notifications.notify_decorator'],
+        deprecated_for_removal=True,
+        deprecated_since='17.0.0',
+        deprecated_reason="""
+Monkey patching nova is not tested, not supported, and is a barrier
+for interoperability.
+""",
         help="""
 List of modules/decorators to monkey patch.
 
@@ -83,7 +95,6 @@ modules.
 Possible values:
 
 * nova.compute.api:nova.notifications.notify_decorator
-* nova.api.ec2.cloud:nova.notifications.notify_decorator
 * [...]
 
 Related options:

nova/conf/notifications.py

@@ -67,6 +67,14 @@ API service.
         'default_publisher_id',
         default='$my_ip',
         deprecated_group='DEFAULT',
+        deprecated_for_removal=True,
+        deprecated_since='17.0.0',
+        deprecated_reason="""
+This option is only used when ``monkey_patch=True`` and
+``monkey_patch_modules`` is configured to specify the legacy notify_decorator.
+Since the monkey_patch and monkey_patch_modules options are deprecated, this
+option is also deprecated.
+""",
         help="""
 Default publisher_id for outgoing notifications. If you consider routing
 notifications using different publisher, change this value accordingly.

nova/notifications/base.py

@@ -46,6 +46,8 @@ LOG = log.getLogger(__name__)
 CONF = nova.conf.CONF
 
 
+# TODO(mriedem): Remove this when CONF.monkey_patch, CONF.monkey_patch_modules
+# and CONF.default_publisher_id are removed in Rocky.
 def notify_decorator(name, fn):
     """Decorator for notify which is used from utils.monkey_patch().
 

nova/utils.py

@@ -498,8 +498,9 @@ def format_remote_path(host, path):
     return "%s:%s" % (safe_ip_format(host), path)
 
 
+# TODO(mriedem): Remove this in Rocky.
 def monkey_patch():
-    """If the CONF.monkey_patch set as True,
+    """DEPRECATED: If the CONF.monkey_patch set as True,
     this function patches a decorator
     for all functions in specified modules.
     You can set decorators for each modules
@@ -517,6 +518,7 @@ def monkey_patch():
     # If CONF.monkey_patch is not True, this function do nothing.
     if not CONF.monkey_patch:
         return
+    LOG.warning('Monkey patching nova is deprecated for removal.')
     if six.PY2:
         is_method = inspect.ismethod
     else:

releasenotes/notes/deprecate-monkey-patch-5cd654924694b9ae.yaml

@@ -0,0 +1,17 @@
+---
+deprecations:
+  - |
+    The following configuration options are deprecated for removal:
+
+    - ``[DEFAULT]/monkey_patch``
+    - ``[DEFAULT]/monkey_patch_modules``
+
+    Monkey patching nova is not tested, not supported, and is a barrier to
+    interoperability. If you have code which relies on monkey patching
+    decorators, for example, for notifications, please propose those changes
+    upstream.
+
+    As a result, the following option is also deprecated for removal since it
+    is only used when specified with ``[DEFAULT]/monkey_patch_modules``:
+
+    - ``[notifications]/default_publisher_id``