Deprecate available filters in favor of enabled

Previously, Tempest's default for scheduler_available_filters was
'all'. This was different from Nova's default enabled_filters, which
does *not* include all possible filters available in Nova. Thus, in a
deployment where both options were kept at their default value,
Tempest's is_scheduler_filter_enabled() would return True for all
filters, even if those filters weren't enabled in Nova. In addition,
the 'available' wording could be made clearer. This patch deprecates
scheduler_available_filters, replacing it with
scheduler_enabled_filters. The latter has its default value set to
Nova's enabled_filters default.

Related-bug: 1628443
Change-Id: I5c87865dc650d383ee006d36b6d52cdd90577ab9

releasenotes/notes/deprecate-scheduler-available-filters-cbca2017ba3cf2aa.yaml

@@ -0,0 +1,13 @@
+---
+deprecations:
+  - |
+    The ``scheduler_available_filters`` option is being deprecated in favor of
+    ``scheduler_enabled_filters``. The new name is more indicative of what the
+    option means. ``scheduler_enabled_filters``'s default value is set to the
+    default value of Nova's ``enabled_filters``.
+    ``scheduler_available_filters``'s default was `all`. There was confusion
+    around this value. Sometimes it was understood to mean the default Nova
+    filters are enabled, other times it was understood to mean all filters are
+    enabled. While `all` is still allowed for ``scheduler_enabled_filters`` for
+    backwards compatibility, it is strongly recommended to provide an explicit
+    list of filters that matches what's configured in nova.conf.

tempest/common/compute.py

@@ -44,15 +44,14 @@ LOG = logging.getLogger(__name__)
 def is_scheduler_filter_enabled(filter_name):
     """Check the list of enabled compute scheduler filters from config.
 
-    This function checks whether the given compute scheduler filter is
-    available and configured in the config file. If the
-    scheduler_available_filters option is set to 'all' (Default value. which
-    means default filters are configured in nova) in tempest.conf then, this
-    function returns True with assumption that requested filter 'filter_name'
-    is one of available filter in nova ("nova.scheduler.filters.all_filters").
+    This function checks whether the given compute scheduler filter is enabled
+    in the nova config file. If the scheduler_enabled_filters option is set to
+    'all' in tempest.conf then, this function returns True with assumption that
+    requested filter 'filter_name' is one of the enabled filters in nova
+    ("nova.scheduler.filters.all_filters").
     """
 
-    filters = CONF.compute_feature_enabled.scheduler_available_filters
+    filters = CONF.compute_feature_enabled.scheduler_enabled_filters
     if not filters:
         return False
     if 'all' in filters:

tempest/config.py

@@ -472,20 +472,30 @@ ComputeFeaturesGroup = [
     cfg.BoolOpt('config_drive',
                 default=True,
                 help='Enable special configuration drive with metadata.'),
-    cfg.ListOpt('scheduler_available_filters',
-                default=['all'],
-                help="A list of enabled filters that nova will accept as hints"
-                     " to the scheduler when creating a server. A special "
-                     "entry 'all' indicates all filters that are included "
-                     "with nova are enabled. Empty list indicates all filters "
-                     "are disabled. The full list of available filters is in "
-                     "nova.conf: filter_scheduler.enabled_filters. If the "
+    cfg.ListOpt('scheduler_enabled_filters',
+                default=["RetryFilter", "AvailabilityZoneFilter",
+                         "ComputeFilter", "ComputeCapabilitiesFilter",
+                         "ImagePropertiesFilter",
+                         "ServerGroupAntiAffinityFilter",
+                         "ServerGroupAffinityFilter"],
+                help="A list of enabled filters that Nova will accept as "
+                     "hints to the scheduler when creating a server. If the "
                      "default value is overridden in nova.conf by the test "
                      "environment (which means that a different set of "
                      "filters is enabled than what is included in Nova by "
-                     "default) then, this option must be configured to "
+                     "default), then this option must be configured to "
                      "contain the same filters that Nova uses in the test "
-                     "environment."),
+                     "environment. A special entry 'all' indicates all "
+                     "filters that are included with Nova are enabled. If "
+                     "using 'all', be sure to enable all filters in "
+                     "nova.conf, as tests can fail in unpredictable ways if "
+                     "Nova's and Tempest's enabled filters don't match. "
+                     "Empty list indicates all filters are disabled. The "
+                     "full list of enabled filters is in nova.conf: "
+                     "filter_scheduler.enabled_filters.",
+                deprecated_opts=[cfg.DeprecatedOpt(
+                    'scheduler_available_filters',
+                    group='compute-feature-enabled')]),
     cfg.BoolOpt('swap_volume',
                 default=False,
                 help='Does the test environment support in-place swapping of '