Deprecated set_latent

With the introduction of set_defaults, as well as new documentation
features for default values in oslo_config, the CORS middleware
has been placed in the odd position where its configuration behaves
inconsistently. A user may use set_defaults to set persisted default
values that may be overridden, or they may use set_latent to add values
that will be applied to every request. As both of these serve essentially
the same function, and the latter is only necessary if it is feasible to
configure multiple allowed_origins with different CORS properties.

With the depecation of multiple configuration blocks, it is no longer
necessary to maintain this feature. Therefore, this patch adds the necessary
deprecation flags, and removes it from the documentation.

Change-Id: Icd44684b3d05ff6a07665348c08adff8245f2523

doc/source/cors.rst

@@ -79,18 +79,6 @@ reasonable human-readable string::
     allowed_origin=*
     allow_methods=GET
 
-If your software requires specific headers or methods for proper operation, you
-may include these as latent properties. These will be evaluated in addition
-to any found in configuration::
-
-    from oslo_middleware import cors
-
-    app = cors.CORS(your_wsgi_application)
-    app.set_latent(allow_headers=['X-System-Header'],
-                   expose_headers=['X-System-Header'],
-                   allow_methods=['GET','PATCH'])
-
-
 Configuration for pastedeploy
 -----------------------------
 
@@ -116,12 +104,6 @@ configuration, this may be done as follows.::
     # Optional field, in case the program name is different from the project:
     oslo_config_program = oslo_project_name-api
 
-    # This method also permits setting latent properties, for any origins set
-    # in oslo config.
-    latent_allow_headers=X-Auth-Token
-    latent_expose_headers=X-Auth-Token
-    latent_methods=GET,PUT,POST
-
 Configuration Options
 ---------------------
 

oslo_middleware/cors.py

@@ -14,6 +14,7 @@
 
 # Default allowed headers
 import copy
+from debtcollector import moves
 import logging
 
 from oslo_config import cfg
@@ -243,6 +244,9 @@ class CORS(base.ConfigurableMiddleware):
                     'allow_headers': allow_headers
                 }
 
+    @moves.moved_method('set_defaults',
+                        message='CORS.set_latent has been deprecated in favor '
+                                'of oslo_middleware.cors.set_defaults')
     def set_latent(self, allow_headers=None, allow_methods=None,
                    expose_headers=None):
         '''Add a new latent property for this middleware.