Logstash ruby plugin file to collect spinnaker metrics in logstash

parse_event.rb

require "json"
require 'socket'

@hostname = Socket.gethostname

def register(params)
end

# Turns one Netflix spectator application feed into many generic metrics
# suitable for ingestion in influxdb.
def filter(event)

  applicationName = event.get("applicationName")

  return [] if event.get("metrics").nil?

  # event format: https://www.spinnaker.io/reference/monitoring/#metrics-overview
  return event.get("metrics").map { |metricName,metricBody|
    metricBody["values"].map { |instance|
      result = {
        "value" => instance["values"][0]["v"],
        "@timestamp" => Time.at(instance["values"][0]["t"]/1000).utc.strftime("%Y-%m-%dT%H:%M:%SZ"),
        "host" => @hostname,
        "name" => "#{applicationName}.#{metricName}"
      }
      unless instance["tags"].nil?
        result = instance["tags"].map{ |t| [t["key"], t["value"]] }.to_h.merge(result)
      end
      ::LogStash::Event.new(result)
    }
  }.flatten
end

# Tests that run whenever logstash starts.
# To run tests without starting the rest of logstash:
# bin/logstash -e "filter { ruby { path => './parse_event.rb'} }" -t
test "It should emit multiple events from one spectator summary page." do
  parameters do
    {}
  end

  in_event {
    test_file = "./spinnaker.log"
    if File.file? test_file
      file = File.read test_file
      body = JSON.parse(file)
      body.values.flatten
    else
      JSON.parse(`curl localhost:7002/spectator/metrics`)
    end
  }

  expect("splits up the events") do |events|
    puts "(FYI) example event:", events[0].to_hash
    events.size > 0
  end
end