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Connect Wukong processors to Vayacondios
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This Wukong plugin integrates Wukong with Vayacondios.

It provides

  • a default Vayacondios client for the entire deploy pack with options that make it configurable by all wu-* tools
  • methods for the Processor class to announce/search events and set/get/delete/search stashes.
  • new processors which announce events and set stashes on each input record for use in flows


To include the Wukong-Vayacondios plugin in your deploy pack, first add it to your Gemfile:

# in Gemfile.rb
gem 'wukong-vayacondios', git: '', branch: 'leslie'

You may also have to add the following line to config/initializers/plugins.rb if you want to make Wukong-Vayacondios globally accessible (depends on how you've configured the environment of your deploy pack).

# in config/initializers/plugins.rb
require 'wukong-vayacondios'

Default Vayacondios Client

Wukong-Vayacondios provides a default Vayacondios::Client at Wukong::Deploy.vayacondios_client. This client object is automatically initialized and configured during the startup of any wu-*-tool.


The default Vayacondios client is configured by the following settings which should appear on all wu-*-tools if Wukong-Vayacondios is loaded in your deploy pack:

  • vcd -- turn on interaction with Vayacondios (dry_run mode otherwise)
  • vcd_host -- host for Vayacondios server
  • vcd_port -- port for Vayacondios server

If the --vcd option is not passed on the command-line:

$ wu-local my_flow --vcd

or set in a configuration file

# in config/settings.yml
vcd: true

then all interactions with Vayacondios using the default client will be in "dry run" mode -- logging but not performing any requests.


Once the Wukong environment has booted and code in your processor or model is running you can directly interact with the Vayacondios client at any time:

# in app/models/my_model.rb
def perform_some_risky_action!
  Wukong::Deploy.vayacondios_client.announce(:risky_actions, { id:, ... })

It's more common to write to Vayacondios from processors or dataflows which is why convenience methods and classes have already been created for those contexts, as detailed in the next sections.

New Processor Methods

The following methods are now added to the Wukong::Processor class

  • announce -- for announcing an event
  • events -- for searching events
  • get -- for retrieving a stash
  • stashes -- for searching stashes
  • set -- for merging data into a stash
  • set_many -- for merging data into many stashes via a query
  • set! -- for replacing data in a stash
  • set_many! -- for replacing data in many stashes via a query
  • delete -- for deleting a stash
  • delete_many -- for deleting many stashes via a query

Each method delegates to the corresponding method of Vayacondios::Client.

New Processors

The following new processors are defined:

  • lookup -- for using an input record to form a query whose response is yielded
  • announce -- for using an input record to announce an event
  • stash -- for using an input record to merge in a stash
  • stash! -- for using an input record to replace in a stash

Vayacondios requires a topic for each of these operations to be well-defined so each processor can be either instantiated with a topic when used in a dataflow, as in the following example:

# in messy_source.rb
Wukong.dataflow(:messy_source) do
  from_json | recordize(model: SourceModel) | 
      select(&:valid?) | do_more_stuff | ... | to_json,
      select(&:invalid?) | announce(topic: 'malformed')

or the input records themselves must have a topic property.

The lookup, stash, and stash! processors work similarly.

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