Adds volume-usage-audit-period config directive >= kilo.

This change adds the config directive called
volume-usage-audit-period for versions >= kilo.

Also, According to the doc change I90dff1b5c2a7dd2943cfa7ff25bb63c08eb7986d,
messagingv2 should be the default for anything > Icehouse.

So, this change also sets the following configuration section for
versions >= mitaka.

[oslo_messaging_notifications]
driver = messagingv2

This change adds a specific configuration context that installs
a crontab entry for running the cinder-volume-usage-audit recurrently.

Change-Id: I0056edaac55210a1a1f509ec908ae61c0ea887df
Closes-Bug: #1623144
Signed-off-by: Jorge Niedbalski <jorge.niedbalski@canonical.com>

config.yaml

@@ -6,7 +6,7 @@ options:
   verbose:
     default: False
     type: boolean
-    description: Enable verbose logging.      
+    description: Enable verbose logging.
   use-syslog:
     type: boolean
     default: False
@@ -368,4 +368,9 @@ options:
     description: |
       Apply system hardening. Supports a space-delimited list of modules
       to run. Supported modules currently include os, ssh, apache and mysql.
-
+  volume-usage-audit-period:
+    default: "month"
+    type: string
+    description: |
+      Time period for which to generate volume usages. The options are hour,
+      day, month, or year.

hooks/cinder_contexts.py

@@ -183,3 +183,22 @@ class RegionContext(OSContextGenerator):
             return {'region': region}
         else:
             return {}
+
+
+class VolumeUsageAuditContext(OSContextGenerator):
+    """This context provides the configuration directive
+    volume_usage_audit_period and also creates a crontab entry
+    for running the cinder-volume-usage-audit script recurrently.
+    """
+    DEFAULT_CRONTAB_PATH = '/etc/cron.d/cinder-volume-usage-audit'
+
+    def __call__(self):
+        log("Installing crontab: %s" % self.DEFAULT_CRONTAB_PATH)
+        with open(self.DEFAULT_CRONTAB_PATH, "w+") as crontab:
+            # The cinder-volume-usage-audit executable will only gather
+            # data that fits on the configured volume-usage-audit-period.
+            crontab.write('0 * * * * root '
+                          '/usr/bin/cinder-volume-usage-audit\n')
+        return {
+            'volume_usage_audit_period': config("volume-usage-audit-period")
+        }

hooks/cinder_utils.py

@@ -226,7 +226,8 @@ BASE_RESOURCE_MAP = OrderedDict([
                      context.BindHostContext(),
                      context.WorkerConfigContext(),
                      cinder_contexts.RegionContext(),
-                     context.InternalEndpointContext()],
+                     context.InternalEndpointContext(),
+                     cinder_contexts.VolumeUsageAuditContext()],
         'services': ['cinder-api', 'cinder-volume', 'cinder-scheduler',
                      'haproxy']
     }),

templates/kilo/cinder.conf

@@ -62,6 +62,8 @@ os_region_name = {{ region }}
 {% endfor -%}
 {% endif -%}
 
+volume_usage_audit_period = {{ volume_usage_audit_period }}
+
 {% include "parts/backends" %}
 
 {% include "section-keystone-authtoken-legacy" %}

templates/liberty/cinder.conf

@@ -62,6 +62,8 @@ os_region_name = {{ region }}
 {% endfor -%}
 {% endif -%}
 
+volume_usage_audit_period = {{ volume_usage_audit_period }}
+
 {% include "parts/backends" %}
 
 {% include "section-keystone-authtoken" %}

templates/mitaka/cinder.conf

@@ -62,6 +62,8 @@ os_region_name = {{ region }}
 {% endfor -%}
 {% endif -%}
 
+volume_usage_audit_period = {{ volume_usage_audit_period }}
+
 {% include "parts/backends" %}
 
 {% include "section-keystone-authtoken-mitaka" %}
@@ -77,3 +79,8 @@ lock_path = /var/lock/cinder
 # XXX: hack to work around http://pad.lv/1516085
 #      will be superceeded by SRU to cinder package
 encryption_auth_url = {{ service_protocol }}://{{ service_host }}:{{ service_port }}/v3
+
+[oslo_messaging_notifications]
+# .openstack.common.* is pre-icehouse option. 
+# Check change-id: I90dff1b5c2a7dd2943cfa7ff25bb63c08eb7986d
+driver = messagingv2

unit_tests/test_cinder_contexts.py

@@ -358,3 +358,12 @@ class TestCinderContext(CharmTestCase):
         self.config.return_value = 'two'
         ctxt = contexts.RegionContext()()
         self.assertEqual('two', ctxt['region'])
+
+    @patch('__builtin__.open')
+    def test_volume_usage_audit_context(self, _open):
+        self.config.return_value = 'month'
+        ctxt = contexts.VolumeUsageAuditContext()()
+        _open.assert_called_with(
+            contexts.VolumeUsageAuditContext.DEFAULT_CRONTAB_PATH, "w+")
+        self.assertEqual(self.config.return_value,
+                         ctxt["volume_usage_audit_period"])