Merge pull request #127 from cookpad/errm/outbox_message_bus

Add a message bus for transactional outbox deliveries

lib/streamy/event_handler.rb

@@ -1,4 +1,5 @@
 require "active_support/core_ext/hash/indifferent_access"
+require "ostruct"
 
 module Streamy
  class EventHandler

lib/streamy/message_buses/outbox_message_bus.rb

@@ -0,0 +1,22 @@
+require "streamy/kafka_configuration"
+require "waterdrop"
+require "active_support/core_ext/hash/indifferent_access"
+require "active_support/json"
+
+module Streamy
+ module MessageBuses
+ class OutboxMessageBus < MessageBus
+ def initialize(config)
+ @model = config[:model]
+ end
+
+ def deliver(key:, topic:, payload:, priority:)
+ @model.create(key: key, topic: topic, payload: payload)
+ end
+
+ def deliver_many(messages)
+ @model.create(messages.map { |message| message.except(:priority) })
+ end
+ end
+ end
+end

streamy.gemspec

@@ -45,4 +45,5 @@ Gem::Specification.new do |spec| # rubocop:disable Metrics/BlockLength
  spec.add_dependency "avro_turf", "~> 1.3.0"
  spec.add_dependency "waterdrop", ">= 2.4.10", "< 3.0.0"
  spec.add_dependency "webmock", "~> 3.3"
+ spec.add_dependency "ostruct"
 end

test/avro_deserializer_test.rb

@@ -1,6 +1,7 @@
 require "test_helper"
 require "avro_turf/test/fake_confluent_schema_registry_server"
 require "webmock/minitest"
+require "ostruct"
 
 module Streamy
  class AvroDeserializerTest < Minitest::Test

test/message_buses/outbox_message_bus_test.rb

@@ -0,0 +1,101 @@
+require "test_helper"
+require "waterdrop"
+require "streamy/message_buses/outbox_message_bus"
+
+module Streamy
+ class OutboxMessageBusTest < Minitest::Test
+ attr_reader :bus
+
+ def setup
+ @model = mock("outbox_model")
+ @bus = MessageBuses::OutboxMessageBus.new(model: @model)
+ end
+
+ def example_delivery(priority)
+ bus.deliver(
+ payload: payload.to_s,
+ key: "prk-sg-001",
+ topic: "charcuterie",
+ priority: priority
+ )
+ end
+
+ def payload
+ {
+ type: "sausage",
+ body: { meat: "pork", herbs: "sage" },
+ event_time: "2018"
+ }
+ end
+
+ def expected_event(key: "prk-sg-001")
+ {
+ payload: {
+ type: "sausage",
+ body: {
+ meat: "pork",
+ herbs: "sage"
+ },
+ event_time: "2018"
+ }.to_s,
+ key: key,
+ topic: "charcuterie"
+ }
+ end
+
+ def test_standard_priority_deliver
+ @model.expects(:create).with(expected_event)
+ example_delivery(:standard)
+ end
+
+ def test_low_priority_deliver
+ @model.expects(:create).with(expected_event)
+ example_delivery(:low)
+ end
+
+ def test_essential_priority_deliver
+ @model.expects(:create).with(expected_event)
+ example_delivery(:essential)
+ end
+
+ def test_all_priority_delivery
+ @model.expects(:create).with(expected_event)
+ example_delivery(:essential)
+
+ @model.expects(:create).with(expected_event)
+ example_delivery(:low)
+
+ @model.expects(:create).with(expected_event)
+ example_delivery(:standard)
+ end
+
+ def test_batch_delivery
+ @model.expects(:create).with([
+ expected_event(key: "prk-sg-001"),
+ expected_event(key: "prk-sg-002"),
+ expected_event(key: "prk-sg-003")
+ ])
+
+ bus.deliver_many([
+ {
+ payload: payload.to_s,
+ key: "prk-sg-001",
+ topic: "charcuterie",
+ priority: :standard
+ },
+ {
+ payload: payload.to_s,
+ key: "prk-sg-002",
+ topic: "charcuterie",
+ priority: :standard
+ },
+ {
+ payload: payload.to_s,
+ key: "prk-sg-003",
+ topic: "charcuterie",
+ priority: :standard
+ }
+ ])
+ end
+ end
+end