Class: LogStash::Agent

Inherits:
Clamp::Command
  • Object
show all
Defined in:
lib/logstash/agent.rb

Direct Known Subclasses

SpecialAgent

Constant Summary collapse

DEFAULT_INPUT = 
"input { stdin { type => stdin } }"
DEFAULT_OUTPUT = 
"output { stdout { codec => rubydebug } }"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*params) ⇒ Agent

Returns a new instance of Agent.



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# File 'lib/logstash/agent.rb', line 94

def initialize(*params)
  super(*params)
  @logger = Cabin::Channel.get(LogStash)
  @pipelines = {}
  @pipeline_settings ||= { :pipeline_id => "main" }
  @upgrade_mutex = Mutex.new
  @config_loader = LogStash::Config::Loader.new(@logger)
end

Instance Attribute Details

#config_loader ⇒ Object (readonly)

Returns the value of attribute config_loader.



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# File 'lib/logstash/agent.rb', line 14

def config_loader
  @config_loader
end

#pipelines ⇒ Object (readonly)

Returns the value of attribute pipelines.



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# File 'lib/logstash/agent.rb', line 14

def pipelines
  @pipelines
end

Instance Method Details

#clean_state? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/agent.rb', line 432

def clean_state?
  @pipelines.empty?
end

#configure ⇒ Object

Do any start-time configuration.

Log file stuff, plugin path checking, etc.



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# File 'lib/logstash/agent.rb', line 254

def configure
  configure_logging(log_file)
  configure_plugin_paths(plugin_paths)
end

#configure_logging(path) ⇒ Object

Point logging at a specific path.



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# File 'lib/logstash/agent.rb', line 260

def configure_logging(path)
  # Set with the -v (or -vv...) flag
  if quiet?
    @logger.level = :error
  elsif verbose?
    @logger.level = :info
  elsif debug?
    @logger.level = :debug
  else
    # Old support for the -v and -vv stuff.
    if verbosity? && verbosity?.any?
      # this is an array with length of how many times the flag is given
      if verbosity?.length == 1
        @logger.warn("The -v flag is deprecated and will be removed in a future release. You should use --verbose instead.")
        @logger.level = :info
      else
        @logger.warn("The -vv flag is deprecated and will be removed in a future release. You should use --debug instead.")
        @logger.level = :debug
      end
    else
      @logger.level = :warn
    end
  end

  if log_file
    # TODO(sissel): Implement file output/rotation in Cabin.
    # TODO(sissel): Catch exceptions, report sane errors.
    begin
      @log_fd.close if @log_fd
      @log_fd = File.new(path, "a")
    rescue => e
      fail(I18n.t("logstash.agent.configuration.log_file_failed",
                  :path => path, :error => e))
    end

    puts "Sending logstash logs to #{path}."
    @logger.unsubscribe(@logger_subscription) if @logger_subscription
    @logger_subscription = @logger.subscribe(@log_fd)
  else
    @logger.subscribe(STDOUT)
  end

  # TODO(sissel): redirect stdout/stderr to the log as well
  # http://jira.codehaus.org/browse/JRUBY-7003
end

#configure_plugin_paths(paths) ⇒ Object

add the given paths for ungemified/bare plugins lookups

Parameters:

  • paths (String, Array<String>) —

    plugins path string or list of path strings to add



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# File 'lib/logstash/agent.rb', line 308

def configure_plugin_paths(paths)
  Array(paths).each do |path|
    fail(I18n.t("logstash.agent.configuration.plugin_path_missing", :path => path)) unless File.directory?(path)
    LogStash::Environment.add_plugin_path(path)
  end
end

#create_pipeline(settings) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 379

def create_pipeline(settings)
  begin
    config = fetch_config(settings)
  rescue => e
    @logger.error("failed to fetch pipeline configuration", :message => e.message)
    return
  end

  begin
    LogStash::Pipeline.new(config, settings)
  rescue => e
    @logger.error("fetched an invalid config", :config => config, :reason => e.message)
    return
  end
end

#debug_config=(debug_config) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 115

def debug_config=(debug_config)
  @config_loader.debug_config = debug_config
  @debug_config = true
end

#execute ⇒ Object

Run the agent. This method is invoked after clamp parses the flags given to this program.



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# File 'lib/logstash/agent.rb', line 141

def execute
  require "logstash/pipeline"
  require "cabin" # gem 'cabin'
  require "logstash/plugin"

  LogStash::ShutdownWatcher.unsafe_shutdown = unsafe_shutdown?
  LogStash::ShutdownWatcher.logger = @logger

  if version?
    show_version
    return 0
  end

  # temporarily send logs to stdout as well if a --log is specified
  # and stdout appears to be a tty
  show_startup_errors = log_file && STDOUT.tty?

  if show_startup_errors
    stdout_logs = @logger.subscribe(STDOUT)
  end
  configure


  if filter_workers
    @logger.warn("--filter-workers is deprecated! Please use --pipeline-workers or -w. This setting will be removed in the next major version!")
    self.pipeline_workers = filter_workers
  end

  # You must specify a config_string or config_path
  if config_string.nil? && config_path.nil?
    fail(I18n.t("logstash.agent.missing-configuration"))
  end

  if auto_reload? && config_path.nil?
    # there's nothing to reload
    fail(I18n.t("logstash.agent.reload-without-config-path"))
  end

  if config_test?
    config_loader = LogStash::Config::Loader.new(@logger)
    config_str = config_loader.format_config(config_path, config_string)
    begin
      # currently the best strategy to validate the configuration
      # is creating a pipeline instance and checking for exceptions
      LogStash::Pipeline.new(config_str)
      @logger.terminal "Configuration OK"
      return 0
    rescue => e
      @logger.fatal I18n.t("logstash.agent.invalid-configuration", :error => e.message)
      return 1
    end
  end

  register_pipeline("main", @pipeline_settings.merge({
                        :config_string => config_string,
                        :config_path => config_path,
                        :debug_config => debug_config?,
                        :allow_env => allow_env?
                        }))

  sigint_id = trap_sigint()
  sigterm_id = trap_sigterm()
  sighup_id = trap_sighup()

  @logger.unsubscribe(stdout_logs) if show_startup_errors

  @logger.info("starting agent")

  start_pipelines

  return 1 if clean_state?

  @thread = Thread.current # this var is implicilty used by Stud.stop?

  Stud.stoppable_sleep(reload_interval) # sleep before looping

  if auto_reload?
    Stud.interval(reload_interval) { reload_state! }
  else
    while !Stud.stop?
      if clean_state? || running_pipelines?
        sleep 0.5
      else
        break
      end
    end
  end

  shutdown

  return 0
rescue LogStash::ConfigurationError => e
  @logger.unsubscribe(stdout_logs) if show_startup_errors
  @logger.error I18n.t("logstash.agent.error", :error => e)
  if !config_test?
    @logger.info I18n.t("logstash.agent.configtest-flag-information")
  end
  return 1
rescue => e
  @logger.unsubscribe(stdout_logs) if show_startup_errors
  @logger.warn(I18n.t("oops"), :error => e, :class => e.class.name, :backtrace => e.backtrace)
  return 1
ensure
  @log_fd.close if @log_fd
  Stud::untrap("INT", sigint_id) unless sigint_id.nil?
  Stud::untrap("TERM", sigterm_id) unless sigterm_id.nil?
  Stud::untrap("HUP", sighup_id) unless sighup_id.nil?
end

#fail(message) ⇒ Object

def warn

Raises:



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# File 'lib/logstash/agent.rb', line 135

def fail(message)
  raise LogStash::ConfigurationError, message
end

#fetch_config(settings) ⇒ Object

Pipeline Aux methods ##



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# File 'lib/logstash/agent.rb', line 474

def fetch_config(settings)
  @config_loader.format_config(settings[:config_path], settings[:config_string])
end

#pipeline_batch_delay=(pipeline_batch_delay_value) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 111

def pipeline_batch_delay=(pipeline_batch_delay_value)
  @pipeline_settings[:pipeline_batch_delay] = validate_positive_integer(pipeline_batch_delay_value)
end

#pipeline_batch_size=(pipeline_batch_size_value) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 107

def pipeline_batch_size=(pipeline_batch_size_value)
  @pipeline_settings[:pipeline_batch_size] = validate_positive_integer(pipeline_batch_size_value)
end

#pipeline_workers=(pipeline_workers_value) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 103

def pipeline_workers=(pipeline_workers_value)
  @pipeline_settings[:pipeline_workers] = validate_positive_integer(pipeline_workers_value)
end

#register_pipeline(pipeline_id, settings) ⇒ Object

register_pipeline - adds a pipeline to the agent’s state

Parameters:

  • pipeline_id (String) —

    pipeline string identifier

  • settings (Hash) —

    settings that will be passed when creating the pipeline. keys should be symbols such as :pipeline_workers and :pipeline_batch_delay



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# File 'lib/logstash/agent.rb', line 355

def register_pipeline(pipeline_id, settings)
  pipeline = create_pipeline(settings.merge(:pipeline_id => pipeline_id))
  return unless pipeline.is_a?(LogStash::Pipeline)
  if @auto_reload && pipeline.non_reloadable_plugins.any?
    @logger.error(I18n.t("logstash.agent.non_reloadable_config_register"),
                  :pipeline_id => pipeline_id,
                  :plugins => pipeline.non_reloadable_plugins.map(&:class))
    return
  end
  @pipelines[pipeline_id] = pipeline
end

#reload_pipeline!(id) ⇒ Object

since this method modifies the @pipelines hash it is wrapped in @upgrade_mutex in the parent call ‘reload_state!`



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# File 'lib/logstash/agent.rb', line 438

def reload_pipeline!(id)
  old_pipeline = @pipelines[id]
  new_pipeline = create_pipeline(old_pipeline.original_settings)
  return if new_pipeline.nil?

  if old_pipeline.config_str == new_pipeline.config_str
    @logger.debug("no configuration change for pipeline",
                  :pipeline => id, :config => old_pipeline.config_str)
  elsif new_pipeline.non_reloadable_plugins.any?
    @logger.error(I18n.t("logstash.agent.non_reloadable_config_reload"),
                  :pipeline_id => id,
                  :plugins => new_pipeline.non_reloadable_plugins.map(&:class))
  else
    @logger.log("fetched new config for pipeline. upgrading..",
                 :pipeline => id, :config => new_pipeline.config_str)
    upgrade_pipeline(id, new_pipeline)
  end
end

#reload_state! ⇒ Object 



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# File 'lib/logstash/agent.rb', line 367

def reload_state!
  @upgrade_mutex.synchronize do
    @pipelines.each do |pipeline_id, _|
      begin
        reload_pipeline!(pipeline_id)
      rescue => e
        @logger.error(I18n.t("oops"), :error => e, :backtrace => e.backtrace)
      end
    end
  end
end

#running_pipeline?(pipeline_id) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/agent.rb', line 421

def running_pipeline?(pipeline_id)
  thread = @pipelines[pipeline_id].thread
  thread.is_a?(Thread) && thread.alive?
end

#running_pipelines? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/agent.rb', line 415

def running_pipelines?
  @upgrade_mutex.synchronize do
    @pipelines.select {|pipeline_id, _| running_pipeline?(pipeline_id) }.any?
  end
end

#shutdown ⇒ Object

Pipeline CRUD ##



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# File 'lib/logstash/agent.rb', line 345

def shutdown(pipeline)
  pipeline.shutdown do
    ::LogStash::ShutdownWatcher.start(pipeline)
  end
end

#shutdown_pipelines ⇒ Object 



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# File 'lib/logstash/agent.rb', line 403

def shutdown_pipelines
  @pipelines.each { |id, _| stop_pipeline(id) }
end

#start_pipeline(id) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 457

def start_pipeline(id)
  pipeline = @pipelines[id]
  return unless pipeline.is_a?(LogStash::Pipeline)
  return if pipeline.ready?
  @logger.info("starting pipeline", :id => id)
  Thread.new do
    LogStash::Util.set_thread_name("pipeline.#{id}")
    begin
      pipeline.run
    rescue => e
      @logger.error("Pipeline aborted due to error", :exception => e, :backtrace => e.backtrace)
    end
  end
  sleep 0.01 until pipeline.ready?
end

#start_pipelines ⇒ Object 



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# File 'lib/logstash/agent.rb', line 395

def start_pipelines
  @pipelines.each { |id, _| start_pipeline(id) }
end

#stop_pipeline(id) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 407

def stop_pipeline(id)
  pipeline = @pipelines[id]
  return unless pipeline
  @logger.log("stopping pipeline", :id => id)
  pipeline.shutdown { LogStash::ShutdownWatcher.start(pipeline) }
  @pipelines[id].thread.join
end

#trap_sighup ⇒ Object 



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# File 'lib/logstash/agent.rb', line 337

def trap_sighup
  Stud::trap("HUP") do
    @logger.warn(I18n.t("logstash.agent.sighup"))
    reload_state!
  end
end

#trap_sigint ⇒ Object

Signal Trapping ##



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# File 'lib/logstash/agent.rb', line 316

def trap_sigint
  Stud::trap("INT") do
    if @interrupted_once
      @logger.fatal(I18n.t("logstash.agent.forced_sigint"))
      exit
    else
      @logger.warn(I18n.t("logstash.agent.sigint"))
      Thread.new(@logger) {|logger| sleep 5; logger.warn(I18n.t("logstash.agent.slow_shutdown")) }
      @interrupted_once = true
      Stud.stop!(@thread)
    end
  end
end

#trap_sigterm ⇒ Object 



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# File 'lib/logstash/agent.rb', line 330

def trap_sigterm
  Stud::trap("TERM") do
    @logger.warn(I18n.t("logstash.agent.sigterm"))
    Stud.stop!(@thread)
  end
end

#upgrade_pipeline(pipeline_id, new_pipeline) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 426

def upgrade_pipeline(pipeline_id, new_pipeline)
  stop_pipeline(pipeline_id)
  @pipelines[pipeline_id] = new_pipeline
  start_pipeline(pipeline_id)
end

#validate_positive_integer(str_arg) ⇒ Object 



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# File 'lib/logstash/agent.rb', line 120

def validate_positive_integer(str_arg)
  int_arg = str_arg.to_i
  if str_arg !~ /^\d+$/ || int_arg < 1
    raise ArgumentError, "Expected a positive integer, got '#{str_arg}'"
  end

  int_arg
end

#warn(message) ⇒ Object

Emit a warning message.

Raises:



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# File 'lib/logstash/agent.rb', line 130

def warn(message)
  # For now, all warnings are fatal.
  raise LogStash::ConfigurationError, message
end