Class: Fluent::DockerMetricsInput

Inherits:
Input
  • Object
show all
Defined in:
lib/fluent/plugin/in_docker_metrics.rb

Defined Under Namespace

Classes: BlkioSectorsParser, BlkioStatsParser, CGroupStatsParser, KeyValueStatsParser, TimerWatcher

Instance Method Summary collapse

Constructor Details

#initialize ⇒ DockerMetricsInput

Returns a new instance of DockerMetricsInput.



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 17

def initialize
  super
  require 'socket'
  require 'docker'
  @hostname = Socket.gethostname
  @with_systemd = File.exists?("#{@cgroup_path}/systemd")
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 25

def configure(conf)
  super

end

#emit_container_metric(id, name, metric_type, metric_filename, opts = {}) ⇒ Object 



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 62

def emit_container_metric(id, name, metric_type, metric_filename, opts = {})

  if @with_systemd
    path = "#{@cgroup_path}/#{metric_type}/system.slice/docker-#{id}.scope/#{metric_filename}"
  else
    path = "#{@cgroup_path}/#{metric_type}/docker/#{id}/#{metric_filename}"
  end

  if File.exists?(path)
    # the order of these two if's matters
    if metric_filename == 'blkio.sectors'
      parser = BlkioSectorsParser.new(path, metric_filename.gsub('.', '_'))
    elsif metric_type == 'blkio'
      parser = BlkioStatsParser.new(path, metric_filename.gsub('.', '_'))
    else
      parser = KeyValueStatsParser.new(path, metric_filename.gsub('.', '_'))
    end
    time = Engine.now
    tag = "#{@tag_prefix}.#{metric_filename}"
    mes = MultiEventStream.new
    parser.parse_each_line do |data|
      next if not data
      # TODO: address this more elegantly
      if data['key'] =~ /^(?:cpuacct|blkio|memory_stat_pg)/
        data['type'] = 'counter'
      else
        data['type'] = 'gauge'
      end
      data["hostname"] = @hostname
      data["id"] = id
      data["name"] = name.sub(/^\//, '')
      mes.add(time, data)
    end
    router.emit_stream(tag, mes)
  else
    nil
  end
end

#get_metrics ⇒ Object

Metrics collection methods



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 44

def get_metrics
  ids = @container_ids || list_container_ids
  ids.each do |id, name|
    emit_container_metric(id, name, 'memory', 'memory.stat') 
    emit_container_metric(id, name, 'cpuacct', 'cpuacct.stat') 
    emit_container_metric(id, name, 'blkio', 'blkio.io_serviced') 
    emit_container_metric(id, name, 'blkio', 'blkio.io_service_bytes') 
    emit_container_metric(id, name, 'blkio', 'blkio.io_queued') 
    emit_container_metric(id, name, 'blkio', 'blkio.sectors') 
  end
end

#list_container_ids ⇒ Object 



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 56

def list_container_ids
  Docker::Container.all.map do |container|
    [container.id, container.info["Names"].first]
  end
end

#run ⇒ Object 



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 36

def run
  @loop.run
rescue
  log.error "unexpected error", :error=>$!.to_s
  log.error_backtrace
end

#shutdown ⇒ Object 



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 101

def shutdown
  @loop.stop
  @thread.join
end

#start ⇒ Object 



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# File 'lib/fluent/plugin/in_docker_metrics.rb', line 30

def start
  @loop = Coolio::Loop.new
  tw = TimerWatcher.new(@stats_interval, true, @log, &method(:get_metrics))
  tw.attach(@loop)
  @thread = Thread.new(&method(:run))
end