class Puppet::Indirector::Queue

Implements the :queue abstract indirector terminus type, for storing model instances to a message queue, presumably for the purpose of out-of-process handling of changes related to the model.

Relies upon Puppet::Util::Queue for registry and client object management, and specifies a default queue type of :stomp, appropriate for use with a variety of message brokers.

It’s up to the queue client type to instantiate itself correctly based on Puppet configuration information.

A single queue client is maintained for the abstract terminus, meaning that you can only use one type of queue client, one message broker solution, etc., with the indirection mechanism.

Per-indirection queues are assumed, based on the indirection name. If the :catalog indirection makes use of this :queue terminus, queue operations work against the “catalog” queue. It is up to the queue client library to handle queue creation as necessary (for a number of popular queuing solutions, queue creation is automatic and not a concern).

Public Class Methods

intern(message) click to toggle source

converts the message from deserialized format to an actual model instance.

# File lib/puppet/indirector/queue.rb, line 59
def self.intern(message)
  result = nil
  benchmark :info, "Loaded queued #{indirection.name}" do
    result = model.convert_from(:pson, message)
  end
  result
end
new(*args) click to toggle source
Calls superclass method Puppet::Indirector::Terminus.new 
# File lib/puppet/indirector/queue.rb, line 25
def initialize(*args)
  super
end
queue() click to toggle source 
# File lib/puppet/indirector/queue.rb, line 45
def self.queue
  indirection_name
end
subscribe() { |intern| ... } click to toggle source

Provides queue subscription functionality; for a given indirection, use this method on the terminus to subscribe to the indirection-specific queue. Your block will be executed per new indirection model received from the queue, with obj being the model instance.

# File lib/puppet/indirector/queue.rb, line 70
def self.subscribe
  client.subscribe(queue) do |msg|
    begin
      yield(self.intern(msg))
    rescue => detail
      Puppet.log_exception(detail, "Error occured with subscription to queue #{queue} for indirection #{indirection_name}: #{detail}")
    end
  end
end

Public Instance Methods

client() click to toggle source

Returns the singleton queue client object.

# File lib/puppet/indirector/queue.rb, line 54
def client
  self.class.client
end
find(request) click to toggle source

Queue has no idiomatic "find"

# File lib/puppet/indirector/queue.rb, line 30
def find(request)
  nil
end
queue() click to toggle source 
# File lib/puppet/indirector/queue.rb, line 49
def queue
  self.class.queue
end
save(request) click to toggle source

Place the request on the queue

# File lib/puppet/indirector/queue.rb, line 35
def save(request)
    result = nil
    benchmark :info, "Queued #{indirection.name} for #{request.key}" do
      result = client.publish_message(queue, request.instance.render(:pson))
    end
    result
rescue => detail
    raise Puppet::Error, "Could not write #{request.key} to queue: #{detail}\nInstance::#{request.instance}\n client : #{client}"
end