Add MiqQueue#tracking_label

many times we add a task_id for logging only.
As we are getting away from task_id,
we don't want to loose the logging.

This allows us to transition away from task_id
The tracking_label will be set in the target system,
so a single request can be traced through the various systems

app/models/miq_queue.rb

@@ -109,6 +109,7 @@ def self.put(options)
     options[:queue_name]  ||= create_with_options[:queue_name] || "generic"
     options[:msg_timeout] ||= create_with_options[:msg_timeout] || TIMEOUT
     options[:task_id]      = $_miq_worker_current_msg.try(:task_id) unless options.key?(:task_id)
+    options[:tracking_label] = Thread.current[:tracking_label] || options[:task_id] unless options.key?(:tracking_label)
     options[:role]         = options[:role].to_s unless options[:role].nil?
 
     options[:args] = [options[:args]] if options[:args] && !options[:args].kind_of?(Array)

app/models/miq_queue_worker_base/runner.rb

@@ -104,6 +104,7 @@ def deliver_queue_message(msg)
 
     begin
       $_miq_worker_current_msg = msg
+      Thread.current[:tracking_label] = msg.tracking_label || msg.task_id
       status, message, result = msg.deliver
 
       if status == MiqQueue::STATUS_TIMEOUT
@@ -122,6 +123,7 @@ def deliver_queue_message(msg)
       msg.unget
     ensure
       $_miq_worker_current_msg = nil # to avoid log messages inadvertantly prefixed by previous task_id
+      Thread.current[:tracking_label] = nil
       #
       # This tells the broker to release any memory being held on behalf of this process
       # and reset the global broker handle ($vim_broker_client).