Class: Pipemaster::Launcher

Inherits:
Object
  • Object
show all
Defined in:
lib/pipemaster/launcher.rb

Class Method Summary collapse

Class Method Details

.daemonize!(options = nil) ⇒ Object

We don’t do a lot of standard daemonization stuff:

* umask is whatever was set by the parent process at startup
  and can be set in config.ru and config_file, so making it
  0000 and potentially exposing sensitive log data can be bad
  policy.
* don't bother to chdir("/") here since unicorn is designed to
  run inside APP_ROOT.  Pipemaster will also re-chdir() to
  the directory it was started in when being re-executed
  to pickup code changes if the original deployment directory
  is a symlink or otherwise got replaced.



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# File 'lib/pipemaster/launcher.rb', line 23

def self.daemonize!(options = nil)
  $stdin.reopen("/dev/null")

  # We only start a new process group if we're not being reexecuted
  # and inheriting file descriptors from our parent
  unless ENV['PIPEMASTER_FD']
    if options
      # grandparent - reads pipe, exits when master is ready
      #  \_ parent  - exits immediately ASAP
      #      \_ unicorn master - writes to pipe when ready

      rd, wr = IO.pipe
      grandparent = $$
      if fork
        wr.close # grandparent does not write
      else
        rd.close # unicorn master does not read
        Process.setsid
        exit if fork # parent dies now
      end

      if grandparent == $$
        # this will block until HttpServer#join runs (or it dies)
        master_pid = (rd.readpartial(16) rescue nil).to_i
        unless master_pid > 1
          warn "master failed to start, check stderr log for details"
          exit!(1)
        end
        exit 0
      else # unicorn master process
        options[:ready_pipe] = wr
      end
    else # backwards compat
      exit if fork
      Process.setsid
      exit if fork
    end
    # $stderr/$stderr can/will be redirected separately in the Pipemaster config
    Pipemaster::Configurator::DEFAULTS[:stderr_path] = "/dev/null"
    Pipemaster::Configurator::DEFAULTS[:stdout_path] = "/dev/null"
  end
end