Class: SkyEye::Exec

Inherits:
Object
  • Object
show all
Defined in:
lib/skyeye/exec.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#config ⇒ Object

Returns the value of attribute config.



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# File 'lib/skyeye/exec.rb', line 9

def config
  @config
end

Instance Method Details

#deregister_alarms_matching!(pattern) ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 56

def deregister_alarms_matching!(pattern)
  cw = AWS::CloudWatch.new
  alarms = cw.client.describe_alarms

  to_delete = []

  alarms.data[:metric_alarms].each do |alarm|
    if alarm[:alarm_name] =~ pattern
      to_delete << alarm[:alarm_name]
    end
  end

  if to_delete.size > 0
    @logger.info "De-Register Alarms #{to_delete.inspect}"
    cw.alarms.delete(*to_delete)
  end
end

#deregister_aws_alarms! ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 48

def deregister_aws_alarms!
  @config[:watches].keys.each do |resource_type|
    unless resource_type == :instance
      deregister_alarms_matching!(/^skyeye::#{resource_type}::/)
    end
  end
end

#deregister_instance_alarms! ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 44

def deregister_instance_alarms!
  deregister_alarms_matching!(/^skyeye::instance::#{instance_id}::/)
end

#dimension_values_for_resource_type(resource_type) ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 81

def dimension_values_for_resource_type(resource_type)
  values = []

  case resource_type
  when :elb
    AWS::ELB.new.load_balancers.each do |load_balancer|
      values << [{ name: "LoadBalancerName", value: load_balancer.name }]
    end
  when :rds
    AWS::RDS.new.db_instances.each do |db_instance|
      values << [{ name: "DBInstanceIdentifier", value: db_instance.db_instance_identifier }]
    end
  when :elasticache
    AWS::ElastiCache.new.client.describe_cache_clusters(show_cache_node_info: true).data[:cache_clusters].each do |cluster|
      cluster[:cache_nodes].each do |node|
        values << [{ name: "CacheClusterId", value: cluster[:cache_cluster_id] },
                   { name: "CacheNodeId", value: node[:cache_node_id] }]
      end
    end
  when :sqs
    AWS::SQS.new.queues.each do |queue|
      values << [{ name: "QueueName", value: queue.arn.split(/:/)[-1] }]
    end
  end

  values
end

#go(*args) ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 15

def go(*args)
  config_file = ENV["SKYEYE_CONFIG_FILE"] || "/etc/skyeye.yml"

  unless File.exists?(config_file)
    puts "Missing #{config_file}. You can set the path to this file by exporting SKYEYE_CONFIG_FILE."
    return
  end

  @config = YAML.load(File.read(config_file))
  @logger = Logger.new(STDOUT)
  @mutex = Mutex.new

  if args.size == 0
    start!
  elsif args[0] == "register:instance"
    load_or_register_topics!
    register_instance_alarms!
  elsif args[0] == "deregister:instance"
    deregister_instance_alarms!
  elsif args[0] == "deregister:aws"
    deregister_aws_alarms!
  elsif args[0] == "register:aws"
    load_or_register_topics!
    register_aws_alarms!
  else
    puts "valid commands: [de]register:(aws|instance)"
  end
end

#instance_id ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 11

def instance_id
  @instance_id ||= open("http://169.254.169.254/latest/meta-data/instance-id").read
end

#kill!(e) ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 190

def kill!(e)
  @mutex.synchronize do
    @killed_by = e
  end
end

#load_or_register_topics! ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 280

def load_or_register_topics!
  sns = AWS::SNS.new

  current_topics = sns.client.list_topics

  arns = []

  (@config[:topics] || ["skyeye-alerts"]).each do |topic_name|
    current_topic = current_topics[:topics].find do |topic|
      topic[:topic_arn].split(/:/)[-1] == topic_name
    end

    if current_topic
      arns << current_topic[:topic_arn]
    else
      arn = sns.topics.create(topic_name).arn
      arns << arn

      @logger.info "Created Topic #{arn}"
    end
  end

  @config[:arns] = arns
end

#namespace_for_resource_type(resource_type) ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 109

def namespace_for_resource_type(resource_type)
  case resource_type
  when :instance
    return "AWS/EC2"
  when :elb
    return "AWS/ELB"
  when :rds
    return "AWS/RDS"
  when :elasticache
    return "AWS/ElastiCache"
  when :sqs
    return "AWS/SQS"
  end
end

#register_alarms_for_watches!(resource_type, dimension_values) ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 133

def register_alarms_for_watches!(resource_type, dimension_values)
  cw = AWS::CloudWatch.new

  dimension_values.each do |dimension_value|
    @config[:watches][resource_type].each do |watch|
      [:warning, :critical].each do |threshold|
        target = dimension_value.map { |v| v[:value] }.join("_")
        alarm_name = "skyeye::#{resource_type}::#{target}::#{watch[:name]}-#{threshold}"

        alarm = cw.alarms[alarm_name]

        unless alarm.exists?
          is_command = !!watch[:command]
          raise "Cannot specify command for non-instance watch" if is_command && resource_type != :instance

          if is_command || watch[threshold]
            @logger.info "Register Alarm #{alarm_name}"

            cw.alarms.create(alarm_name, {
              namespace: is_command ? @config[:namespace] : namespace_for_resource_type(resource_type),
              metric_name: watch[:name],
              dimensions: dimension_value,
              comparison_operator: watch[:comparison_operator] || "GreaterThanThreshold",
              evaluation_periods: 1,
              period: (watch[:period] || @config[:alarm_periods][threshold] || 5) * 60,
              statistic: watch[:statistic] || "Maximum",
              threshold: is_command ? (threshold == :warning ? 0 : 1) : watch[threshold],
              insufficient_data_actions: (threshold == :critical && is_command ? @config[:arns] : []),
              actions_enabled: true,
              alarm_actions: @config[:arns],
              alarm_description: "skyeye: #{watch.to_json}",
            })
          end
        end
      end
    end
  end
end

#register_aws_alarms! ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 74

def register_aws_alarms!
  @config[:watches].each do |resource_type, watches|
    dimension_values = dimension_values_for_resource_type(resource_type)
    register_alarms_for_watches!(resource_type, dimension_values) if dimension_values
  end
end

#register_instance_alarms! ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 124

def register_instance_alarms!
  cw = AWS::CloudWatch.new

  watches = @config[:watches][:instance]
  dimension_values = [[{ name: "InstanceId", value: instance_id }]]

  register_alarms_for_watches!(:instance, dimension_values)
end

#shutdown! ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 274

def shutdown!
  @mutex.synchronize do
    @running = false
  end
end

#start! ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 172

def start!
  @running = true
  @logger.info "SkyEye starting."

  namespace = @config[:namespace] || "skyeye"

  @threads = @config[:watches][:instance].map do |w|
    thread_for_watch(namespace, w)
  end.compact

  @threads.each(&:join)

  if @killed_by
    @logger.error(@killed_by.to_s + " " + @killed_by.backtrace.join("\n"))
    raise @killed_by
  end
end

#thread_for_watch(namespace, watch) ⇒ Object 



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# File 'lib/skyeye/exec.rb', line 196

def thread_for_watch(namespace, watch)
  return nil if watch[:type] == "aws"
  raise "missing name" unless watch[:name]

  Thread.new do 
    last_check = nil

    interval = (watch[:interval] || 5) * 60

    do_check = lambda do |&block|
      if !last_check || (Time.now - last_check > interval)
        last_check = Time.now
        block.call
      end
    end

    begin
      loop do
        running = true

        @mutex.synchronize do
          running = @running && !@killed_by
        end

        break unless running

        do_check.call do
          @logger.info "[CHECK] [#{instance_id}] #{watch[:name]}::#{watch[:type]} #{watch[:command] || ""}"

          if watch[:command]
            command = watch[:command]
            message = nil
            status = nil

            @mutex.synchronize do
              status = Open4::popen4(command) do |pid, stdin, stdout, stderr|
                message = "#{watch[:name]} :: #{stdout.readlines.join(" ").gsub(/\n/, " ").chomp} :: #{stderr.readlines.join(" ").gsub(/\n/, " ").chomp}"
              end

              case status
              when 0
                @logger.info message
              when 1
                @logger.warn message
              when 2
                @logger.error message
              else
                @logger.warn message
              end

              cw = AWS::CloudWatch.new.client

              cw.put_metric_data({
                namespace: namespace,
                metric_data: [{
                  metric_name: watch[:name],
                  dimensions: [{
                    :name => "InstanceId",
                    :value => instance_id
                  }],
                  value: status.exitstatus,
                  unit: "None"
                }]
              })
            end
          else
            raise "Missing command or aws id for watch #{watch[:name]}"
          end
        end

        sleep 1
      end
    rescue Exception => e
      kill!(e)
    end
  end
end