ServiceOrchestrator

ServiceOrchestrator is a lightweight dependency injection framework, greatly inspired by the awesome Morphine gem.

Compared to Morphine, it automatically wires dependencies between services thanks to some simple conventions.

If you wonder if you need this library, please check out my article about Services in Rails.

Install the gem and add it to the application's Gemfile by executing:

$ bundle add service_orchestrator

The framework is composed of 2 main Ruby classes:

• ServiceOrchestrator::Container which registers all the services and wires the dependencies.
• ServiceOrchestrator::Service that any service with dependencies inherits from.

Conventions

• a service has a single public method named call.
• the call method of a service takes N named arguments.
• don't use instance variables inside the Service Ruby class.

First, declare a container in order to register all your services.

class ApplicationContainer < ServiceOrchestrator::Container
  
  register :onboarding, 'OnBoardingService'

  register :analytics_tracker, 'AmplitudeAnalyticsTrackerService'

  private

  register :amplitude_sdk do
    AmplitudeSDK.new(api_key: Rails.application.credentials.amplitude.api_key)
  end
end

Then, declare your services.

class AmplitudeAnalyticsTrackerService < ServiceOrchestrator::Service
  dependency :amplitude_sdk

  def call(event_name:, properties: {})
    amplitude_sdk.send_event(event_name, properties)
  end

class OnboardingService < ServiceOrchestrator::Service
  dependency :analytics_tracker
  
  def call(attributes:)
    User.create(attributes).tap do |user|
      analytics_tracker.call(:new_user, { email: user.email })
    end
  end
end

Create an instance of a container to get access to your services.

container = ApplicationContainer.new

container.onboarding.call({ email: 'john@doe.net', name: 'John' })

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/nocoffeehq/service_orchestrator.

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