Module: Riser::Daemon

Includes:
ServerSignal
Defined in:
lib/riser/daemon.rb

Constant Summary collapse

DEFAULT = 
{
  daemonize: true,
  daemon_name: 'ruby'.freeze,
  daemon_debug: $DEBUG,
  daemon_nochdir: true,
  daemon_umask: 0037,
  status_file: nil,
  listen_address: nil,
  server_polling_interval_seconds: 3,
  server_restart_overlap_seconds: 0,
  server_privileged_user: nil,
  server_privileged_group: nil,

  signal_stop_graceful:      SIGNAL_STOP_GRACEFUL,
  signal_stop_forced:        SIGNAL_STOP_FORCED,
  signal_stat_get_and_reset: SIGNAL_STAT_GET_AND_RESET,
  signal_stat_get_no_reset:  SIGNAL_STAT_GET_NO_RESET,
  signal_stat_stop:          SIGNAL_STAT_STOP,
  signal_restart_graceful:   SIGNAL_RESTART_GRACEFUL,
  signal_restart_forced:     SIGNAL_RESTART_FORCED
}.freeze

Constants included from ServerSignal

ServerSignal::SIGNAL_RESTART_FORCED, ServerSignal::SIGNAL_RESTART_GRACEFUL, ServerSignal::SIGNAL_STAT_GET_AND_RESET, ServerSignal::SIGNAL_STAT_GET_NO_RESET, ServerSignal::SIGNAL_STAT_STOP, ServerSignal::SIGNAL_STOP_FORCED, ServerSignal::SIGNAL_STOP_GRACEFUL

Class Method Summary collapse

Class Method Details

.get_gid(group) ⇒ Object 



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# File 'lib/riser/daemon.rb', line 622

def get_gid(group)
  get_id(group, Process::GID)
end

.get_id(name, id_mod) ⇒ Object 



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# File 'lib/riser/daemon.rb', line 604

def get_id(name, id_mod)
  if (name) then
    case (name)
    when Integer
      name
    when /\A \d+ \z/x
      name.to_i
    else
      id_mod.from_name(name)
    end
  end
end

.get_uid(user) ⇒ Object 



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# File 'lib/riser/daemon.rb', line 618

def get_uid(user)
  get_id(user, Process::UID)
end

.running?(status_file_path) ⇒ Boolean

set the ‘status_file’ parameter of the ‘start_daemon’ method to call this method.

Returns:

  • (Boolean) 


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# File 'lib/riser/daemon.rb', line 653

def self.running?(status_file_path)
  StatusFile.locked? status_file_path
end

.start_daemon(config, &block) ⇒ Object

should be executed on the main thread sharing the stack with signal(2) handlers



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# File 'lib/riser/daemon.rb', line 659

def start_daemon(config, &block) # :yields: socket_server
  c = DEFAULT.dup
  c.update(config)

  File.umask(c[:daemon_umask])

  if (c[:status_file]) then
    status_file = StatusFile.new(c[:status_file])
    status_file.open
    status_file.lock or abort("#{c[:daemon_name]} daemon is already running.")
  end

  if (c[:daemonize]) then
    logger = Syslog::Logger.new(c[:daemon_name])
    def logger.close
      Syslog::Logger.syslog = nil
      Syslog.close
      nil
    end
  else
    logger = Logger.new(STDOUT)
    logger.progname = c[:daemon_name]
    def logger.close        # not close STDOUT
    end
  end

  if (c[:daemon_debug]) then
    logger.level = Logger::DEBUG
  else
    logger.level = Logger::INFO
  end

  if (c[:listen_address].respond_to? :call) then
    sockaddr_get = c[:listen_address]
  else
    sockaddr_get = proc{ c[:listen_address] }
  end

  euid = Daemon.get_uid(c[:server_privileged_user])
  egid = Daemon.get_gid(c[:server_privileged_group])

  root_process = RootProcess.new(logger, sockaddr_get, c[:server_polling_interval_seconds], c[:server_restart_overlap_seconds], euid, egid, &block)
  [ [ :signal_stop_graceful,      proc{ root_process.signal_stop_graceful }          ],
    [ :signal_stop_forced,        proc{ root_process.signal_stop_forced }            ],
    [ :signal_stat_get_and_reset, proc{ root_process.signal_stat_get(reset: true) }  ],
    [ :signal_stat_get_no_reset,  proc{ root_process.signal_stat_get(reset: false) } ],
    [ :signal_stat_stop,          proc{ root_process.signal_stat_stop }              ],
    [ :signal_restart_graceful,   proc{ root_process.signal_restart_graceful }       ],
    [ :signal_restart_forced,     proc{ root_process.signal_restart_forced }         ]
  ].each{|sig_key, sig_hook|
    if (signal = c[sig_key]) then
      Signal.trap(signal, &sig_hook)
    end
  }
  Signal.trap(:CHLD) { root_process.signal_server_down }

  if (c[:daemonize]) then
    Process.daemon(c[:daemon_nochdir])
  end

  # update after process ID changes in daemonization.
  if (c[:status_file]) then
    status_file.write({ 'pid' => $$ }.to_yaml)
  end

  status = root_process.start
  exit(status)
end