CircleCI::Parallel

CircleCI::Parallel provides simple Ruby APIs for syncing CircleCI parallel nodes and transferring files between the nodes.

Installation

Add this line to your application's Gemfile:

gem 'circleci-parallel'

And then execute:

$ bundle install

Usage

Before using CircleCI::Parallel:

• Add parallel: true to the command that you'll use CircleCI::Parallel in your circle.yml.
• Set up parallelism for your project from the CircleCI web console.

CircleCI::Parallel uses SSH for syncing nodes and transferring data between nodes.

# circle.yml
test:
  override:
    - ruby test.rb:
        parallel: true

# test.rb
require 'circleci/parallel'

CircleCI::Parallel.configure do |config|
  # This hook will be invoked on every node.
  # The current working directory in this hook is set to the local data directory
  # where node specific data should be saved in.
  config.on_every_node.before_sync do
    data = do_something
    json = JSON.generate(data)
    File.write('data.json', json)
  end

  # This hook will be invoked only on the master node after downloading all data from slave nodes.
  # The current working directory in this hook is set to the download data directory
  # where all node data are gathered into.
  # The directory structure on the master node will be the following:
  #
  #     .
  #     ├── node0
  #     │   └── node_specific_data_you_saved_on_node0.txt
  #     ├── node1
  #     │   └── node_specific_data_you_saved_on_node1.txt
  #     └── node2
  #         └── node_specific_data_you_saved_on_node2.txt
  config.on_master_node.after_download do
    merged_data = {}

    Dir.glob('*/data.json') do |path|
      json = File.read(path)
      data = JSON.parse(json)
      node_name = File.dirname(path)
      merged_data[node_name] = data
    end

    p merged_data
  end
end

# Sync all nodes in the same build and gather all node data into the master node.
# Invoking this method blocks until the sync and the data transfer is complete.
CircleCI::Parallel.sync

See API docs for more details.

License

The gem is available as open source under the terms of the MIT License.