Merge "Improve help message for scheduler_available_filters"
diff --git a/tempest/config.py b/tempest/config.py
index 47eb427..a3d4d78 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -422,10 +422,16 @@
                 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 are enabled. Empty "
-                     "list indicates all filters are disabled. The full "
-                     "available list of filters is in nova.conf: "
-                     "DEFAULT.scheduler_available_filters"),
+                     "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: DEFAULT.scheduler_available_filters. 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 "
+                     "contain the same filters that Nova uses in the test "
+                     "environment."),
     cfg.BoolOpt('swap_volume',
                 default=False,
                 help='Does the test environment support in-place swapping of '
diff --git a/tempest/test.py b/tempest/test.py
index 51f0a6a..af97932 100644
--- a/tempest/test.py
+++ b/tempest/test.py
@@ -164,7 +164,15 @@
 
 
 def is_scheduler_filter_enabled(filter_name):
-    """Check the list of enabled compute scheduler filters from config. """
+    """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").
+    """
 
     filters = CONF.compute_feature_enabled.scheduler_available_filters
     if len(filters) == 0: