Merge "Add scheduler-max-attempts flag"

config.yaml

@@ -617,6 +617,17 @@ options:
       .
       Possible Values are positive integers. Any value less than 1 will be
       treated as 1.
+  scheduler-max-attempts:
+    type: int
+    default:
+    description: |
+      The value to be configured for max_attempts property under scheduler.
+      .
+      This is useful for rescheduling instances to hosts when affinity policies
+      are in place as described in the following URL
+      https://docs.openstack.org/nova/latest/admin/troubleshooting/affinity-policy-violated.html
+      .
+      The default 3
   spice-agent-enabled:  # LP: #1856602
     type: boolean
     default: True  # OpenStack's default value.

hooks/nova_cc_context.py

@@ -440,6 +440,8 @@ class NovaConfigContext(ch_context.WorkerConfigContext):
         ctxt['console_access_port'] = hookenv.config('console-access-port')
         ctxt['scheduler_host_subset_size'] = hookenv.config(
             'scheduler-host-subset-size')
+        ctxt['scheduler_max_attempts'] = hookenv.config(
+            'scheduler-max-attempts')
         ctxt['unique_server_names'] = hookenv.config('unique-server-names')
         ctxt['skip_hosts_with_build_failures'] = hookenv.config(
             'skip-hosts-with-build-failures')

templates/ocata/nova.conf

@@ -205,6 +205,10 @@ enabled_filters = {{ scheduler_default_filters }}
 host_subset_size = {{ scheduler_host_subset_size }}
 {%- endif %}
 
+{%- if scheduler_max_attempts %}
+max_attempts = {{ scheduler_max_attempts }}
+{%- endif %}
+
 [api]
 auth_strategy=keystone
 {% if vendor_data or vendor_data_url -%}

templates/pike/nova.conf

@@ -219,6 +219,10 @@ build_failure_weight_multiplier = 0.0
 host_subset_size = {{ scheduler_host_subset_size }}
 {%- endif %}
 
+{%- if scheduler_max_attempts %}
+max_attempts = {{ scheduler_max_attempts }}
+{%- endif %}
+
 [api]
 auth_strategy=keystone
 {% if vendor_data or vendor_data_url -%}

templates/rocky/nova.conf

@@ -221,6 +221,10 @@ build_failure_weight_multiplier = 0.0
 host_subset_size = {{ scheduler_host_subset_size }}
 {%- endif %}
 
+{%- if scheduler_max_attempts %}
+max_attempts = {{ scheduler_max_attempts }}
+{%- endif %}
+
 [api]
 auth_strategy=keystone
 {% if vendor_data or vendor_data_url -%}

templates/train/nova.conf

@@ -235,6 +235,10 @@ build_failure_weight_multiplier = 0.0
 host_subset_size = {{ scheduler_host_subset_size }}
 {%- endif %}
 
+{%- if scheduler_max_attempts %}
+max_attempts = {{ scheduler_max_attempts }}
+{%- endif %}
+
 [api]
 auth_strategy=keystone
 {% if vendor_data or vendor_data_url -%}

unit_tests/test_nova_cc_contexts.py

@@ -341,10 +341,13 @@ class NovaComputeContextTests(CharmTestCase):
         mock_config_ip.side_effect = self.test_config.get
         mock_unit_get.return_value = '127.0.0.1'
         self.test_config.set('scheduler-default-filters', 'TestFilter')
+        self.test_config.set('scheduler-max-attempts', 10)
         self.test_config.set('unique-server-names', 'project')
         ctxt = context.NovaConfigContext()()
         self.assertEqual(ctxt['scheduler_default_filters'],
                          self.config('scheduler-default-filters'))
+        self.assertEqual(ctxt['scheduler_max_attempts'],
+                         self.config('scheduler-max-attempts'))
         self.assertEqual(ctxt['cpu_allocation_ratio'],
                          self.config('cpu-allocation-ratio'))
         self.assertEqual(ctxt['ram_allocation_ratio'],