<NME> kafka_spec.rb
<BEF> require "test_utils"
require "logstash/inputs/kafka"
require 'jruby-kafka'

class LogStash::Inputs::TestKafka < LogStash::Inputs::Kafka
  private
  def queue_event(msg, output_queue)
    super(msg, output_queue)
    # need to raise exception here to stop the infinite loop
    raise LogStash::ShutdownSignal
  end
end

class TestMessageAndMetadata
  attr_reader :topic, :partition, :key, :message
  def initialize(topic, partition, key, message)
    @topic = topic
    @partition = partition
    @key = key
    @message = message
  end
end


class TestKafkaGroup < Kafka::Group
  def run(a_num_threads, a_queue)
    blah = TestMessageAndMetadata.new(@topic, 0, nil, 'Kafka message')
    a_queue << blah
  end
end

describe 'inputs/kafka' do
  let (:kafka_config) {{'topic_id' => 'test'}}
  let (:empty_config) {{}}
  let (:bad_kafka_config) {{'topic_id' => 'test', 'white_list' => 'other_topic'}}
  let (:white_list_kafka_config) {{'white_list' => 'other_topic'}}
  let (:decorated_kafka_config) {{'topic_id' => 'test', 'decorate_events' => true}}

  it "should register" do
    input = LogStash::Plugin.lookup("input", "kafka").new(kafka_config)
    expect {input.register}.to_not raise_error
  end

  it "should register with whitelist" do
    input = LogStash::Plugin.lookup("input", "kafka").new(white_list_kafka_config)
    expect {input.register}.to_not raise_error
  end

  it "should fail with multiple topic configs" do
    input = LogStash::Plugin.lookup("input", "kafka").new(empty_config)
    expect {input.register}.to raise_error
  end

  it "should fail without topic configs" do
    input = LogStash::Plugin.lookup("input", "kafka").new(bad_kafka_config)
    expect {input.register}.to raise_error
  end

  it 'should populate kafka config with default values' do
    kafka = LogStash::Inputs::TestKafka.new(kafka_config)
    insist {kafka.zk_connect} == 'localhost:2181'
    insist {kafka.topic_id} == 'test'
    insist {kafka.group_id} == 'logstash'
    !insist { kafka.reset_beginning }
  end

  it 'should retrieve event from kafka' do
    kafka = LogStash::Inputs::TestKafka.new(kafka_config)
    expect(kafka).to receive(:create_consumer_group) do |options|
      TestKafkaGroup.new(options)
    end
    kafka.register

    logstash_queue = Queue.new
    kafka.run logstash_queue
    e = logstash_queue.pop
    insist { e['message'] } == 'Kafka message'
    insist { e['kafka']['consumer_group'] } == 'logstash'
    insist { e['kafka']['msg_size'] } == 13
    insist { e['kafka']['partition'] } == 0
  end

end
      TestKafkaGroup.new(options)
    end
    kafka.register

    logstash_queue = Queue.new
    kafka.run logstash_queue
    e = logstash_queue.pop
    insist { e['message'] } == 'Kafka message'
    # no metadata by default
    insist { e['kafka']['topic'] } == 'test'
    insist { e['kafka']['consumer_group'] } == 'logstash'
    insist { e['kafka']['msg_size'] } == 13
    insist { e['kafka']['partition'] } == 0
    insist { e['kafka']['key'] } == nil
  end

end
<MSG> add kafka key to metadata

<DFF> @@ -78,6 +78,7 @@ describe 'inputs/kafka' do
     insist { e['kafka']['consumer_group'] } == 'logstash'
     insist { e['kafka']['msg_size'] } == 13
     insist { e['kafka']['partition'] } == 0
+    insist { e['kafka']['key'] } == nil
   end
 
 end
\ No newline at end of file

add kafka key to metadata