Add kombu_failover_strategy option

Adds the kombu_failover_strategy option for configuring
oslo.messaging.rabbit. This will determines how the next RabbitMQ node
is chosen in case the one we are currently connected to becomes
unavailable.

Change-Id: I904e0bb50c12f94a21ad006c3435d94f0104ecf8
Closes-Bug: #1748353

manifests/init.pp

@@ -117,6 +117,12 @@
 #  considered up (integer value).
 #  Defaults to $::os_service_default
 #
+# [*kombu_failover_strategy*]
+#   (Optional) Determines how the next RabbitMQ node is chosen in case the one
+#   we are currently connected to becomes unavailable. Takes effect only if
+#   more than one RabbitMQ node is provided in config. (string value)
+#   Defaults to $::os_service_default
+#
 # [*kombu_ssl_ca_certs*]
 #   (optional) SSL certification authority file (valid only if SSL enabled).
 #   Defaults to $::os_service_default
@@ -239,6 +245,7 @@ class mistral(
   $rabbit_use_ssl                     = $::os_service_default,
   $service_down_time                  = $::os_service_default,
   $report_interval                    = $::os_service_default,
+  $kombu_failover_strategy            = $::os_service_default,
   $kombu_ssl_ca_certs                 = $::os_service_default,
   $kombu_ssl_certfile                 = $::os_service_default,
   $kombu_ssl_keyfile                  = $::os_service_default,
@@ -329,6 +336,7 @@ instead.")
     rabbit_virtual_host         => $rabbit_virtual_host,
     rabbit_ha_queues            => $rabbit_ha_queues,
     rabbit_use_ssl              => $rabbit_use_ssl,
+    kombu_failover_strategy     => $kombu_failover_strategy,
     kombu_ssl_version           => $kombu_ssl_version,
     kombu_ssl_ca_certs          => $kombu_ssl_ca_certs,
     kombu_ssl_certfile          => $kombu_ssl_certfile,

releasenotes/notes/add_rabbit_kombu_options-8185738b6f0d8522.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Adds the kombu_failover_strategy option for configuring oslo.messaging.rabbit.
+    This will determines how the next RabbitMQ node is chosen in case the one we
+    are currently connected to becomes unavailable.

spec/classes/mistral_init_spec.rb

@@ -50,6 +50,7 @@ describe 'mistral' do
       is_expected.to contain_mistral_config('oslo_messaging_rabbit/heartbeat_rate').with_value('<SERVICE DEFAULT>')
       is_expected.to contain_mistral_config('oslo_messaging_rabbit/rabbit_userid').with(:value => '<SERVICE DEFAULT>')
       is_expected.to contain_mistral_config('oslo_messaging_rabbit/kombu_reconnect_delay').with(:value => '<SERVICE DEFAULT>')
+      is_expected.to contain_mistral_config('oslo_messaging_rabbit/kombu_failover_strategy').with(:value => '<SERVICE DEFAULT>')
       is_expected.to contain_mistral_config('coordination/backend_url').with(:value => '<SERVICE DEFAULT>')
       is_expected.to contain_mistral_config('coordination/heartbeat_interval').with(:value => '<SERVICE DEFAULT>')
       is_expected.to contain_mistral_config('keystone_authtoken/auth_uri').with(