Add setting for compatible with older rpc API

Set [upgrade_levels] in nova.conf to compatible
with order rpc API, such as add compute=juno to
enable kilo rpc API compatible with juno compute,
for kilo controller can manage the juno compute node.
According to
https://review.openstack.org/#/c/53944/
http://docs.openstack.org/openstack-ops/content/ops_upgrades_upgrade_levels.html
https://github.com/openstack/nova/search?p=1&q=upgrade_levels&utf8=%E2%9C%93

Change-Id: I42c88ba06d2f1ea4f09dc4925e61cca74625337f

CHANGELOG.md

@@ -24,6 +24,7 @@ This file is used to list changes made in each version of cookbook-openstack-com
 * Move deprecated neutron_*/glance_*/cinder_* configurations to [neutron]/[glance]/[cinder] sections in nova.conf
 * Allow dbsync_timeout to be configurable
 * Make libvirtd service started prior to nova compute service
+* Add [upgrade_levels] in nova.conf to enable rpc API compatible with order version
 
 ## 9.3.1
 * Move auth configuration from api-paste.ini to nova.conf

README.md

@@ -355,6 +355,9 @@ VMware Configuration Attributes
 * `openstack['compute']['vmware']['maximum_objects']` - The maximum number of ObjectContent data objects that should be returned in a single result. (integer value, default 100)
 * `openstack['compute']['vmware']['integration_bridge']` - Name of Integration Bridge (string value, default br-int)
 
+Upgrade levels Attribute
+------------------------
+* `openstack['openstack']['compute']['upgrade_levels']` - The RPC version numbers or release name alias
 
 The following attributes are defined in attributes/default.rb of the common cookbook, but are documented here due to their relevance:
 

attributes/default.rb

@@ -548,3 +548,23 @@ default['openstack']['compute']['vmware']['wsdl_location'] = nil
 default['openstack']['compute']['vmware']['maximum_objects'] = 100
 # Name of Integration Bridge (string value, default br-int)
 default['openstack']['compute']['vmware']['integration_bridge'] = 'br-int'
+
+# Lock the version of RPC messages and allow live upgrading of the services
+# without interruption caused by version mismatch.
+# The configuration options allow the specification of RPC version numbers if desired,
+# but release name alias are also supported.
+# options e.g.:
+# default['openstack']['compute']['upgrade_levels'] = {
+#                                                       'baseapi' => 'juno',
+#                                                       'console' => 'juno',
+#                                                       'consoleauth' => 'juno',
+#                                                       'cert' => 'juno',
+#                                                       'scheduler' => 'juno',
+#                                                       'compute' => 'juno',
+#                                                       'intercell' => 'juno',
+#                                                       'conductor' => '2.0',
+#                                                       'network' => '3.0',
+#                                                       'cells' => 'juno'
+#                                                      }
+# choose the needed ones to set
+default['openstack']['compute']['upgrade_levels'] = nil

spec/nova-common_spec.rb

@@ -786,6 +786,17 @@ describe 'openstack-compute::nova-common' do
           end
         end
       end
+
+      it 'sets the upgrade levels' do
+        node.set['openstack']['compute']['upgrade_levels'] = {
+                                                              'compute' => 'juno',
+                                                              'cert' => '3.0',
+                                                              'network' => 'havana'
+                                                              }
+        node['openstack']['compute']['upgrade_levels'].each do |key, val|
+          expect(chef_run).to render_config_file(file.name).with_section_content('upgrade_levels', /^#{key} = #{val}$/)
+        end
+      end
     end
 
     describe 'rootwrap.conf' do

templates/default/nova.conf.erb

@@ -673,3 +673,13 @@ catalog_info=<%= node['openstack']['compute']['block-storage']['cinder_catalog_i
 
 # Region name of this node (string value)
 os_region_name=<%= node['openstack']['region'] %>
+
+<% if node['openstack']['compute']['upgrade_levels'] -%>
+# Lock the version of RPC messages and allow live upgrading of the services
+# without interruption caused by version mismatch.
+# Add upgrade_levels for order rpc API, ex. compute = juno
+[upgrade_levels]
+<% node['openstack']['compute']['upgrade_levels'].each do |key, val| %>
+<%= key %> = <%= val %>
+<% end -%>
+<% end -%>