[novajoin] Use yaml instead of json for policy file

This replaces the remaining usage of policy.json in novajoin with
policy.yaml, because json format will be deprecated[1].

[1] https://governance.openstack.org/tc/goals/selected/wallaby/migrate-policy-format-from-json-to-yaml.html

Depends-on: https://review.opendev.org/769647
Change-Id: I6272d37c4c5a927236660c96522590face337715

manifests/metadata/novajoin/policy.pp

@@ -16,12 +16,12 @@
 #   Defaults to empty hash.
 #
 # [*policy_path*]
-#   (Optional) Path to the novajoin policy.json file
-#   Defaults to /etc/novajoin/policy.json
+#   (Optional) Path to the novajoin policy.yaml file
+#   Defaults to /etc/novajoin/policy.yaml
 #
 class nova::metadata::novajoin::policy (
   $policies    = {},
-  $policy_path = '/etc/novajoin/policy.json',
+  $policy_path = '/etc/novajoin/policy.yaml',
 ) {
 
   validate_legacy(Hash, 'validate_hash', $policies)
@@ -29,6 +29,7 @@ class nova::metadata::novajoin::policy (
   $policy_defaults = {
     file_path   => $policy_path,
     file_user   => 'root',
+    file_format => 'yaml',
   }
 
   create_resources('openstacklib::policy::base', $policies, $policy_defaults)

spec/classes/nova_metadata_novajoin_policy_spec.rb

@@ -5,7 +5,7 @@ describe 'nova::metadata::novajoin::policy' do
   shared_examples_for 'novajoin policies' do
     let :params do
       {
-        :policy_path => '/etc/novajoin/policy.json',
+        :policy_path => '/etc/novajoin/policy.yaml',
         :policies    => {
           'context_is_admin' => {
             'key'   => 'context_is_admin',
@@ -20,9 +20,10 @@ describe 'nova::metadata::novajoin::policy' do
         :key         => 'context_is_admin',
         :value       => 'foo:bar',
         :file_user   => 'root',
+        :file_format => 'yaml',
       })
       is_expected.to contain_oslo__policy('novajoin_config').with(
-        :policy_file => '/etc/novajoin/policy.json',
+        :policy_file => '/etc/novajoin/policy.yaml',
       )
     end
   end