use task queue for update stack operation

Update stack should use the task queue for direct operation on the
provider (used by scaling/scaledown UI in ems infra)

This commit includes the necessary model changes.

app/models/manageiq/providers/openstack/infra_manager/orchestration_stack.rb

@@ -60,15 +60,19 @@ def raw_status
     raise MiqException::MiqOrchestrationStatusError, err.to_s, err.backtrace
   end
 
-  def queue_post_scaledown_task(services)
+  def queue_post_scaledown_task(services, task_id = nil)
     MiqQueue.put(:class_name  => self.class.name,
                  :expires_on  => Time.now.utc + 2.hours,
-                 :args        => [services],
+                 :args        => [services, task_id],
                  :instance_id => id,
                  :method_name => "post_scaledown_task")
   end
 
-  def post_scaledown_task(services)
+  def post_scaledown_task(services, task_id = nil)
+    task = MiqTask.find(task_id) unless task_id.nil?
+    if task && task.state == MiqTask::STATE_FINISHED && !task.status_ok?
+      raise MiqException::MiqQueueError, "Scaledown update failed, not running post scaledown task"
+    end
     raise MiqException::MiqQueueRetryLater.new(:deliver_on => Time.now.utc + 1.minute) unless raw_status.first == 'UPDATE_COMPLETE'
     services.each(&:delete_service)
   end

app/models/orchestration_stack.rb

@@ -85,6 +85,22 @@ def raw_update_stack(_template, _options = {})
     raise NotImplementedError, _("raw_update_stack must be implemented in a subclass")
   end
 
+  def update_stack_queue(userid, template, options = {})
+    task_opts = {
+      :action => "updating Orchestration Stack for user #{userid}",
+      :userid => userid
+    }
+    queue_opts = {
+      :class_name  => self.class.name,
+      :method_name => 'update_stack',
+      :instance_id => id,
+      :role        => 'ems_operations',
+      :zone        => ext_management_system.my_zone,
+      :args        => [template, options]
+    }
+    MiqTask.generic_action_with_callback(task_opts, queue_opts)
+  end
+
   def update_stack(template, options = {})
     raw_update_stack(template, options)
   end