compute/api: crontab to move deleted instance rows to another database table

Create a crontab which moves deleted instances rows to another database
table that you don't have to backup.
This is done to optimize database management at scale.
Depending on the amount of deleted instances that you get on a daily
basis you want to modify the $max_rows parameter.

This feature is implemented as in nova CLI and addressed by this
blueprint: https://blueprints.launchpad.net/nova/+spec/db-archiving

Change-Id: Id9c50e82347562255e5b31cd1442ec0de46c48eb

manifests/compute/api.pp

@@ -97,6 +97,8 @@ class cloud::compute::api(
     }
   }
 
+  include 'nova::cron::archive_deleted_rows'
+
   @@haproxy::balancermember{"${::fqdn}-compute_api_ec2":
     listening_service => 'ec2_api_cluster',
     server_names      => $::hostname,

spec/classes/cloud_compute_api_spec.rb

@@ -125,6 +125,10 @@ describe 'cloud::compute::api' do
         )
     end
 
+    it 'configure a crontab that move deleted instance rows to another database table' do
+      is_expected.to contain_class('nova::cron::archive_deleted_rows')
+    end
+
     context 'with default firewall enabled' do
       let :pre_condition do
         "class { 'cloud': manage_firewall => true }"