iacobson / umbrella_stage

Subscribes GenStage consumers to producers across Elixir Umbrella apps.

UmbrellaStage

Subscribes GenStage consumers to producers across Elixir Umbrella apps.

Installation

Add umbrella_stage to your list of dependencies in mix.exs:

Elixir >= 1.4 required

def deps do
  [
    {:umbrella_stage, "~> 0.1.1"}
  ]
end

Usage

1. Configuration
   use the UmbrellaStage in the GenStages servers. It required 2 arguments:

• :type - is the GenStage type: :producer, :producer_consumer or :consumer
• :producers - required only for consumers and producer_consumers. It's the list of producers, the consumer (or producer_consumer) will subscribe to, in the following format: {ProducerName, [subscription_options]}

2. Call umbrella_sync_subscribe() in the GenStage init

This version of umbrella_stage implements just the GenStage.sync_subscribe/3 subscription.

Please check this blog post for more details.

Examples

A demo app is available on GitHub.

Consumer

defmodule App1.MyConsumer do
  use UmbrellaStage,
   type: :consumer,
    producers: [
      {MyProducerConsumer, [max_demand: 10]}
    ]

  def init() do
    umbrella_sync_subscribe()
    .....
  end
end

ProducerConsumer

defmodule App2.MyProducerConsumer do
  use UmbrellaStage,
   type: :producer_consumer,
    producers: [
      {MyProducer, [max_demand: 10]}
    ]

  def init() do
    umbrella_sync_subscribe()
    .....
  end
end

Producer

defmodule App3.MyProducer do
  use UmbrellaStage,
    type: :producer

  def init() do
    umbrella_sync_subscribe()
    .....
  end
end