Add minimum value in maximum_instance_delete_attempts

Add minimum value 1 in the maximum_instance_delete_attempts option.

Change-Id: Ic2ce1973971a6827f1a7d00c8c054b6561ab7e72

nova/compute/manager.py

@@ -8138,14 +8138,6 @@ class ComputeManager(manager.Manager):
                 context, filters, expected_attrs=attrs, use_slave=True)
         LOG.debug('There are %d instances to clean', len(instances))
 
-        # TODO(raj_singh): Remove this if condition when min value is
-        # introduced to "maximum_instance_delete_attempts" cfg option.
-        if CONF.maximum_instance_delete_attempts < 1:
-            LOG.warning('Future versions of Nova will restrict the '
-                        '"maximum_instance_delete_attempts" config option '
-                        'to values >=1. Update your configuration file to '
-                        'mitigate future upgrade issues.')
-
         for instance in instances:
             attempts = int(instance.system_metadata.get('clean_attempts', '0'))
             LOG.debug('Instance has had %(attempts)s of %(max)s '

nova/conf/compute.py

@@ -1230,9 +1230,9 @@ Related options:
 ]
 
 instance_cleaning_opts = [
-    # TODO(macsz): add min=1 flag in P development cycle
     cfg.IntOpt('maximum_instance_delete_attempts',
         default=5,
+        min=1,
         help="""
 The number of times to attempt to reap an instance's files.
 
@@ -1242,8 +1242,6 @@ that can be made.
 Possible values:
 
 * Any positive integer defines how many attempts are made.
-* Any value <=0 means no delete attempts occur, but you should use
-  ``instance_delete_interval`` to disable the delete attempts.
 
 Related options:
 

releasenotes/notes/maximum_instance_delete_attempts-option-force-minimum-value-2ce74351650e7b21.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - The ``maximum_instance_delete_attempts`` configuration option has been
+    restricted by the minimum value and now raises a ValueError
+    if the value is less than 1.