Class: Sensu::Client

Inherits:
Object
  • Object
show all
Includes:
Daemon
Defined in:
lib/sensu/client.rb

Instance Attribute Summary collapse

Attributes included from Daemon

#state

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Daemon

#load_extensions, #load_settings, #log_concerns, #setup_logger, #setup_process, #setup_redis, #setup_signal_traps, #setup_transport

Methods included from Utilities

#deep_merge, #random_uuid, #redact_sensitive, #retry_until_true, #testing?

Constructor Details

#initialize(options = {}) ⇒ Client

Returns a new instance of Client.



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# File 'lib/sensu/client.rb', line 18

def initialize(options={})
  super
  @safe_mode = @settings[:client][:safe_mode] || false
  @checks_in_progress = Array.new
end

Instance Attribute Details

#safe_mode ⇒ Object

Returns the value of attribute safe_mode.



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# File 'lib/sensu/client.rb', line 8

def safe_mode
  @safe_mode
end

Class Method Details

.run(options = {}) ⇒ Object 



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# File 'lib/sensu/client.rb', line 10

def self.run(options={})
  client = self.new(options)
  EM::run do
    client.start
    client.setup_signal_traps
  end
end

Instance Method Details

#bootstrap ⇒ Object 



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# File 'lib/sensu/client.rb', line 246

def bootstrap
  setup_keepalives
  setup_subscriptions
  setup_standalone
  @state = :running
end

#complete_checks_in_progress(&block) ⇒ Object 



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# File 'lib/sensu/client.rb', line 234

def complete_checks_in_progress(&block)
  @logger.info('completing checks in progress', {
    :checks_in_progress => @checks_in_progress
  })
  retry_until_true do
    if @checks_in_progress.empty?
      block.call
      true
    end
  end
end

#execute_check_command(check) ⇒ Object 



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# File 'lib/sensu/client.rb', line 91

def execute_check_command(check)
  @logger.debug('attempting to execute check command', {
    :check => check
  })
  unless @checks_in_progress.include?(check[:name])
    @checks_in_progress << check[:name]
    command, unmatched_tokens = substitute_command_tokens(check)
    if unmatched_tokens.empty?
      check[:executed] = Time.now.to_i
      started = Time.now.to_f
      Spawn.process(command, :timeout => check[:timeout]) do |output, status|
        check[:duration] = ('%.3f' % (Time.now.to_f - started)).to_f
        check[:output] = output
        check[:status] = status
        publish_result(check)
        @checks_in_progress.delete(check[:name])
      end
    else
      check[:output] = 'Unmatched command tokens: ' + unmatched_tokens.join(', ')
      check[:status] = 3
      check[:handle] = false
      publish_result(check)
      @checks_in_progress.delete(check[:name])
    end
  else
    @logger.warn('previous check command execution in progress', {
      :check => check
    })
  end
end

#find_client_attribute(tree, path, default) ⇒ Object 



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# File 'lib/sensu/client.rb', line 69

def find_client_attribute(tree, path, default)
  attribute = tree[path.shift]
  if attribute.is_a?(Hash)
    find_client_attribute(attribute, path, default)
  else
    attribute.nil? ? default : attribute
  end
end

#pause ⇒ Object 



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# File 'lib/sensu/client.rb', line 259

def pause
  unless @state == :pausing || @state == :paused
    @state = :pausing
    @timers[:run].each do |timer|
      timer.cancel
    end
    @timers[:run].clear
    @transport.unsubscribe
    @state = :paused
  end
end

#process_check(check) ⇒ Object 



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# File 'lib/sensu/client.rb', line 135

def process_check(check)
  @logger.debug('processing check', {
    :check => check
  })
  if check.has_key?(:command)
    if @settings.check_exists?(check[:name])
      check.merge!(@settings[:checks][check[:name]])
      execute_check_command(check)
    elsif @safe_mode
      check[:output] = 'Check is not locally defined (safe mode)'
      check[:status] = 3
      check[:handle] = false
      check[:executed] = Time.now.to_i
      publish_result(check)
    else
      execute_check_command(check)
    end
  else
    if @extensions.check_exists?(check[:name])
      run_check_extension(check)
    else
      @logger.warn('unknown check extension', {
        :check => check
      })
    end
  end
end

#publish_keepalive ⇒ Object 



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# File 'lib/sensu/client.rb', line 24

def publish_keepalive
  keepalive = @settings[:client].merge({
    :version => VERSION,
    :timestamp => Time.now.to_i
  })
  payload = redact_sensitive(keepalive, @settings[:client][:redact])
  @logger.debug('publishing keepalive', {
    :payload => payload
  })
  @transport.publish(:direct, 'keepalives', MultiJson.dump(payload)) do |info|
    if info[:error]
      @logger.error('failed to publish keepalive', {
        :payload => payload,
        :error => info[:error].to_s
      })
    end
  end
end

#publish_result(check) ⇒ Object 



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# File 'lib/sensu/client.rb', line 51

def publish_result(check)
  payload = {
    :client => @settings[:client][:name],
    :check => check
  }
  @logger.info('publishing check result', {
    :payload => payload
  })
  @transport.publish(:direct, 'results', MultiJson.dump(payload)) do |info|
    if info[:error]
      @logger.error('failed to publish check result', {
        :payload => payload,
        :error => info[:error].to_s
      })
    end
  end
end

#resume ⇒ Object 



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# File 'lib/sensu/client.rb', line 271

def resume
  retry_until_true(1) do
    if @state == :paused
      if @transport.connected?
        bootstrap
        true
      end
    end
  end
end

#run_check_extension(check) ⇒ Object 



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# File 'lib/sensu/client.rb', line 122

def run_check_extension(check)
  @logger.debug('attempting to run check extension', {
    :check => check
  })
  check[:executed] = Time.now.to_i
  extension = @extensions[:checks][check[:name]]
  extension.safe_run do |output, status|
    check[:output] = output
    check[:status] = status
    publish_result(check)
  end
end

#schedule_checks(checks) ⇒ Object 



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# File 'lib/sensu/client.rb', line 187

def schedule_checks(checks)
  check_count = 0
  stagger = testing? ? 0 : 2
  checks.each do |check|
    check_count += 1
    scheduling_delay = stagger * check_count % 30
    @timers[:run] << EM::Timer.new(scheduling_delay) do
      interval = testing? ? 0.5 : check[:interval]
      @timers[:run] << EM::PeriodicTimer.new(interval) do
        check[:issued] = Time.now.to_i
        process_check(check.dup)
      end
    end
  end
end

#setup_keepalives ⇒ Object 



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# File 'lib/sensu/client.rb', line 43

def setup_keepalives
  @logger.debug('scheduling keepalives')
  publish_keepalive
  @timers[:run] << EM::PeriodicTimer.new(20) do
    publish_keepalive
  end
end

#setup_sockets ⇒ Object 



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# File 'lib/sensu/client.rb', line 214

def setup_sockets
  options = @settings[:client][:socket] || Hash.new
  options[:bind] ||= '127.0.0.1'
  options[:port] ||= 3030
  @logger.debug('binding client tcp and udp sockets', {
    :options => options
  })
  EM::start_server(options[:bind], options[:port], Socket) do |socket|
    socket.logger = @logger
    socket.settings = @settings
    socket.transport = @transport
  end
  EM::open_datagram_socket(options[:bind], options[:port], Socket) do |socket|
    socket.logger = @logger
    socket.settings = @settings
    socket.transport = @transport
    socket.protocol = :udp
  end
end

#setup_standalone ⇒ Object 



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# File 'lib/sensu/client.rb', line 203

def setup_standalone
  @logger.debug('scheduling standalone checks')
  standard_checks = @settings.checks.select do |check|
    check[:standalone]
  end
  extension_checks = @extensions.checks.select do |check|
    check[:standalone] && check[:interval].is_a?(Integer)
  end
  schedule_checks(standard_checks + extension_checks)
end

#setup_subscriptions ⇒ Object 



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# File 'lib/sensu/client.rb', line 163

def setup_subscriptions
  @logger.debug('subscribing to client subscriptions')
  @settings[:client][:subscriptions].each do |subscription|
    @logger.debug('subscribing to a subscription', {
      :subscription => subscription
    })
    funnel = [@settings[:client][:name], VERSION, Time.now.to_i].join('-')
    @transport.subscribe(:fanout, subscription, funnel) do |message_info, message|
      begin
        check = MultiJson.load(message)
        @logger.info('received check request', {
          :check => check
        })
        process_check(check)
      rescue MultiJson::ParseError => error
        @logger.error('failed to parse the check request payload', {
          :message => message,
          :error => error.to_s
        })
      end
    end
  end
end

#start ⇒ Object 



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# File 'lib/sensu/client.rb', line 253

def start
  setup_transport
  setup_sockets
  bootstrap
end

#stop ⇒ Object 



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# File 'lib/sensu/client.rb', line 282

def stop
  @logger.warn('stopping')
  pause
  @state = :stopping
  complete_checks_in_progress do
    @transport.close
    super
  end
end

#substitute_command_tokens(check) ⇒ Object 



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# File 'lib/sensu/client.rb', line 78

def substitute_command_tokens(check)
  unmatched_tokens = Array.new
  substituted = check[:command].gsub(/:::([^:].*?):::/) do
    token, default = $1.to_s.split('|', -1)
    matched = find_client_attribute(@settings[:client], token.split('.'), default)
    if matched.nil?
      unmatched_tokens << token
    end
    matched
  end
  [substituted, unmatched_tokens]
end