Align worker configuration option

Align ceilometer charm with worker-multiplier usage as found
across the majority of OpenStack Charms.  Worker configuration
values are set for API, Notification and Collector services
as needed for each release. Note that for Ocata or later, API
services are executed as WSGI apps under Apache which was
already plugged into the standard worker calculation logic
in charm helpers.

This includes dropping of the existing api-worker configuration
option in preference to a calculated approach.

Change-Id: Idba7c3012d9d24b7ae6ef8eade4a5261ef1cbddc
Closes-Bug: #1745189

config.yaml

@@ -71,11 +71,15 @@ options:
     type: string
     default: openstack
     description: RabbitMQ virtual host to request access on rabbitmq-server.
-  api-workers:
-    type: int
-    default: 1
+  worker-multiplier:
+    type: float
+    default:
     description: |
-      Number of workers for Ceilometer API server. (>= Kilo).
+      The CPU core multiplier to use when configuring worker processes for
+      this service. By default, the number of workers for each daemon is set
+      to twice the number of CPU cores a service unit has. When deployed in a
+      LXD container, this default value will be capped to 4 workers unless this
+      configuration option is set.
   # Monitoring config
   nagios_context:
     type: string

lib/ceilometer_contexts.py

@@ -103,7 +103,6 @@ class CeilometerContext(OSContextGenerator):
         ctxt = {
             'port': CEILOMETER_PORT,
             'metering_secret': get_shared_secret(),
-            'api_workers': config('api-workers'),
             'metering_time_to_live': int(config('metering-time-to-live')),
             'event_time_to_live': int(config('event-time-to-live')),
         }

templates/icehouse/ceilometer.conf

@@ -11,6 +11,9 @@ use_syslog = {{ use_syslog }}
 
 {% include "parts/rabbitmq" -%}
 
+collector_workers = {{ workers }}
+notification_workers = {{ workers }}
+
 [api]
 port = {{ port }}
 

templates/kilo/ceilometer.conf

@@ -8,7 +8,9 @@
 debug = {{ debug }}
 verbose = {{ verbose }}
 use_syslog = {{ use_syslog }}
-api_workers = {{ api_workers }}
+api_workers = {{ workers }}
+collector_workers = {{ workers }}
+notification_workers = {{ workers }}
 
 {% include "parts/rabbitmq" -%}
 

templates/mitaka/ceilometer.conf

@@ -8,6 +8,10 @@
 debug = {{ debug }}
 verbose = {{ verbose }}
 use_syslog = {{ use_syslog }}
+api_workers = {{ workers }}
+collector_workers = {{ workers }}
+notification_workers = {{ workers }}
+
 event_pipeline_cfg_file = /etc/ceilometer/event_pipeline_alarm.yaml
 
 {% if gnocchi_url -%}
@@ -20,7 +24,6 @@ event_dispatchers = database
 
 [api]
 port = {{ port }}
-workers = {{ api_workers }}
 
 {% if service_host -%}
 [service_credentials]

templates/ocata/ceilometer.conf

@@ -21,13 +21,12 @@ meter_dispatchers = database
 transport_url = {{ transport_url }}
 {%- endif %}
 
-[api]
-port = {{ port }}
-workers = {{ api_workers }}
-
 [notification]
 workers = {{ workers }}
 
+[collector]
+workers = {{ workers }}
+
 {% if service_host -%}
 [service_credentials]
 auth_url = {{ service_protocol }}://{{ service_host }}:{{ service_port }}

tests/basic_deployment.py

@@ -503,6 +503,9 @@ class CeilometerBasicDeployment(OpenStackAmuletDeployment):
                                               'password':
                                                   ks_rel['service_password']}
 
+        if self._get_openstack_release() >= self.xenial_ocata:
+            del expected['api']
+
         for section, pairs in expected.iteritems():
             ret = u.validate_config_data(unit, conf, section, pairs)
             if ret:

unit_tests/test_ceilometer_contexts.py

@@ -129,7 +129,6 @@ class CeilometerContextsTest(CharmTestCase):
         self.assertEqual(contexts.CeilometerContext()(), {
             'port': 8777,
             'metering_secret': 'mysecret',
-            'api_workers': 1,
             'metering_time_to_live': -1,
             'event_time_to_live': -1,
         })
@@ -143,7 +142,6 @@ class CeilometerContextsTest(CharmTestCase):
         self.assertEqual(context, {
             'port': 8777,
             'metering_secret': 'mysecret',
-            'api_workers': 1,
             'metering_time_to_live': 7776000,
             'event_time_to_live': 7776000,
         })