class Gitlab::QA::Component::Telegraf

def config
  <<~CONFIG
    [global_tags]
      run_type = "${QA_RUN_TYPE}"
      pipeline_id = "${CI_PIPELINE_ID}"
      job_name = "${CI_JOB_NAME}"
    [agent]
      interval = "1s"
      round_interval = true
      metric_batch_size = 1000
      metric_buffer_limit = 10000
      collection_jitter = "0s"
      flush_interval = "10s"
      flush_jitter = "0s"
      precision = ""
      debug = true
      logtarget = "file"
      logfile = "#{LOG_DIR}/telegraf.log"
      hostname = ""
      omit_hostname = false
    [[outputs.influxdb_v2]]
      urls = ["${QA_INFLUXDB_URL}"]
      token = "${QA_INFLUXDB_TOKEN}"
      organization = "gitlab-qa"
      bucket = "test-env-stats"
    [[inputs.docker]]
      endpoint = "unix:///var/run/docker.sock"
      gather_services = false
      container_names = []
      source_tag = false
      container_name_include = []
      container_name_exclude = ["#{name}"]
      timeout = "5s"
      perdevice = false
      perdevice_include = []
      total = true
      total_include = ["cpu", "blkio", "network"]
      docker_label_include = []
      docker_label_exclude = []
  CONFIG
end

def initialize
  super
  @name = DOCKER_IMAGE
  @host_log_dir = "#{Runtime::Env.host_artifacts_dir}/#{@name}"
  @environment = Runtime::Env.variables.slice(
    'QA_INFLUXDB_TOKEN',
    'QA_INFLUXDB_URL',
    'QA_RUN_TYPE',
    'CI_JOB_NAME',
    'CI_PIPELINE_ID'
  )
end

def instance_no_teardown
  if run_telegraf?
    super
  else
    Runtime::Logger.debug("Skipping starting telegraf container!")
    yield self if block_given?
  end
end

def missing_influx_config?
  environment.slice('QA_INFLUXDB_TOKEN', 'QA_INFLUXDB_URL').any? { |_k, v| v.blank? }
end

def prepare
  @telegraf_config = File.open("#{Dir.mktmpdir(nil, ENV.fetch('CI_BUILDS_DIR', nil))}/telegraf.conf",
    'w') do |file|
    file.write(config)
    file.path
  end
  FileUtils.mkdir_p(host_log_dir)
  prepare_docker_image
  prepare_docker_container
end

def run_telegraf?
  Runtime::Env.ci && Runtime::Env.qa_export_test_metrics? && Runtime::Env.qa_run_type && !missing_influx_config?
end

def set_command_args(command)
  command << '-d'
  command << "--name #{name}"
  command << "--user root"
  command << "--entrypoint telegraf"
end

def set_environment(command)
  environment.each { |k, v| command.env(k, v) }
end

def set_volumes(command)
  command.volume(host_log_dir, LOG_DIR)
  command.volume('/var/run/docker.sock', '/var/run/docker.sock')
  command.volume(telegraf_config, '/etc/telegraf/telegraf.conf', :ro)
end

def start
  docker.run(image: image, tag: tag) do |command|
    set_command_args(command)
    set_volumes(command)
    set_environment(command)
  end
end

def teardown
  return unless run_telegraf?
  super
end