Add local_metadata_per_cell option

Indicates that the nova-metadata API service has been deployed
per-cell, so that we can have better performance and data isolation in a
multi-cell deployment. Users should consider the use of this configuration
depending on how neutron is setup. If networks span cells, you might need
to run nova-metadata API service globally. If your networks are segmented
along cell boundaries, then you can run nova-metadata API service per cell.
When running nova-metadata API service per cell, you should also configure
each Neutron metadata-agent to point to the corresponding nova-metadata API
service.

Related-Bug: #1823760

Change-Id: Ia4dc22b2d013e00629f5945b230ab57a3e3a6465

manifests/metadata.pp

@@ -21,6 +21,18 @@
 #   (optional) This option is the time (in seconds) to cache metadata.
 #   Defaults to $::os_service_default
 #
+# [*local_metadata_per_cell*]
+#   (optional) Indicates that the nova-metadata API service has been deployed
+#   per-cell, so that we can have better performance and data isolation in a
+#   multi-cell deployment. Users should consider the use of this configuration
+#   depending on how neutron is setup. If networks span cells, you might need
+#   to run nova-metadata API service globally. If your networks are segmented
+#   along cell boundaries, then you can run nova-metadata API service per cell.
+#   When running nova-metadata API service per cell, you should also configure
+#   each Neutron metadata-agent to point to the corresponding nova-metadata API
+#   service.
+#   Defaults to $::os_service_default
+#
 # DEPRECATED
 #
 # [*vendordata_jsonfile_path*]
@@ -94,6 +106,7 @@ class nova::metadata(
   $neutron_metadata_proxy_shared_secret        = undef,
   $enable_proxy_headers_parsing                = $::os_service_default,
   $metadata_cache_expiration                   = $::os_service_default,
+  $local_metadata_per_cell                     = $::os_service_default,
   # DEPRECATED PARAMETERS
   $vendordata_jsonfile_path                    = undef,
   $vendordata_providers                        = undef,
@@ -138,6 +151,7 @@ class nova::metadata(
   nova_config {
     'DEFAULT/enabled_apis':                        value => $enabled_apis;
     'api/metadata_cache_expiration':               value => $metadata_cache_expiration;
+    'api/local_metadata_per_cell':                 value => $local_metadata_per_cell;
   }
 
   oslo::middleware {'nova_config':

releasenotes/notes/local_metadata_per_cell-5b8f56d8d97510a3.yaml

@@ -0,0 +1,12 @@
+---
+features:
+  - |
+    Indicates that the nova-metadata API service has been deployed
+    per-cell, so that we can have better performance and data isolation in a
+    multi-cell deployment. Users should consider the use of this configuration
+    depending on how neutron is setup. If networks span cells, you might need
+    to run nova-metadata API service globally. If your networks are segmented
+    along cell boundaries, then you can run nova-metadata API service per cell.
+    When running nova-metadata API service per cell, you should also configure
+    each Neutron metadata-agent to point to the corresponding nova-metadata API
+    service.

spec/classes/nova_metadata_spec.rb

@@ -26,6 +26,7 @@ describe 'nova::metadata' do
           :enable_proxy_headers_parsing => '<SERVICE DEFAULT>',
         )
         is_expected.to contain_nova_config('api/metadata_cache_expiration').with('value' => '<SERVICE DEFAULT>')
+        is_expected.to contain_nova_config('api/local_metadata_per_cell').with('value' => '<SERVICE DEFAULT>')
       end
 
       it 'unconfigures neutron_metadata proxy' do
@@ -39,6 +40,7 @@ describe 'nova::metadata' do
         params.merge!({
           :neutron_metadata_proxy_shared_secret        => 'secrete',
           :enable_proxy_headers_parsing                => true,
+          :local_metadata_per_cell                     => true,
           :metadata_cache_expiration                   => 15,
           :vendordata_jsonfile_path                    => '/tmp',
           :vendordata_providers                        => ['StaticJSON', 'DynamicJSON'],
@@ -58,6 +60,7 @@ describe 'nova::metadata' do
       end
 
       it 'configures various stuff' do
+        is_expected.to contain_nova_config('api/local_metadata_per_cell').with('value' => true)
         is_expected.to contain_nova_config('api/metadata_cache_expiration').with('value' => '15')
         is_expected.to contain_nova_config('api/vendordata_jsonfile_path').with('value' => '/tmp')
         is_expected.to contain_nova_config('api/vendordata_providers').with('value' => 'StaticJSON,DynamicJSON')