Bump base image (#538)

[discourse_docker.git] / image / monitor / src / monitor.rb

require 'statsd-ruby'
require 'docker'

$statsd = Statsd.new '10.0.0.1', 8125

module Docker
  class CloseConnectionError < StandardError; end
  class Container
    def name
      info["Names"].first[1..-1]
    end

    def stats
      path = path_for(:stats)

      result = nil

      streamer = lambda do |chunk, remaining, total|
        result ||= chunk
        raise CloseConnectionError if result
      end
      options = { response_block: streamer }.merge(connection.options)

      Excon.get(connection.url + path[1..-1], options) rescue CloseConnectionError

      Docker::Util.parse_json(result)
    end
  end
end

def median(array)
  sorted = array.sort
  len = sorted.length
  return ((sorted[(len - 1) / 2] + sorted[len / 2]) / 2.0).to_i
end


def analyze_container(container)

  data = container.exec(["ps", "-eo", "rss,args"])[0].join("\n").split("\n")
  unicorns = data.grep(/unicorn/).map(&:to_i)
  sidekiqs = data.grep(/sidekiq/).map(&:to_i)

  result = {}

  if unicorns.length > 0
    result["unicorn.max_rss"] = unicorns.max
    result["unicorn.median_rss"] = median(unicorns)
  end

  if sidekiqs.length > 0
     result["sidekiq.max_rss"] = sidekiqs.max
     result["sidekiq.median_rss"] = median(sidekiqs)
  end
  result["total_mem_usage"] = container.stats["memory_stats"]["usage"]

  @prev_stats ||= {}
  prev_stats = @prev_stats[container.name]
  @prev_stats[container.name] = stats = container.stats

  if prev_stats
    cpu_delta = stats["cpu_stats"]["system_cpu_usage"] - prev_stats["cpu_stats"]["system_cpu_usage"]
    app_cpu_delta = stats["cpu_stats"]["cpu_usage"]["total_usage"] - prev_stats["cpu_stats"]["cpu_usage"]["total_usage"]

    result["cpu_usage"] = (app_cpu_delta.to_f / cpu_delta.to_f) * stats["cpu_stats"]["cpu_usage"]["percpu_usage"].length * 100.0
  end

  result

end

def containers
  Docker::Container.all
end

hostname = Docker.info["Name"]

STDERR.puts "#{Time.now} Starting Monitor"

while true

  begin
    containers.each do |c|

      analyze_container(c).each do |k, v|
        if v && v > 0
          $statsd.gauge "#{hostname}.#{c.name}.#{k}", v
        end
      end
    end
  rescue => e
    STDERR.puts e
    STDERR.puts e.backtrace
  end

  sleep 60
end