Module: Qless::Pool::CLI

Extended by:
CLI
Included in:
CLI
Defined in:
lib/qless/pool/cli.rb

Instance Method Summary collapse

Instance Method Details

#daemonize ⇒ Object 



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# File 'lib/qless/pool/cli.rb', line 53

def daemonize
  raise 'First fork failed' if (pid = fork) == -1
  exit unless pid.nil?
  Process.setsid
  raise 'Second fork failed' if (pid = fork) == -1
  exit unless pid.nil?
end

#manage_pidfile(pidfile) ⇒ Object 



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# File 'lib/qless/pool/cli.rb', line 61

def manage_pidfile(pidfile)
  return unless pidfile
  pid = Process.pid
  if File.exist? pidfile
    if process_still_running? pidfile
      raise "Pidfile already exists at #{pidfile} and process is still running."
    else
      File.delete pidfile
    end
  else
    FileUtils.mkdir_p File.dirname(pidfile)
  end
  File.open pidfile, "w" do |f|
    f.write pid
  end
  at_exit do
    if Process.pid == pid
      File.delete pidfile
    end
  end
end

#parse_options ⇒ Object 



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# File 'lib/qless/pool/cli.rb', line 20

def parse_options
  opts = Trollop::options do
    version "qless-pool #{VERSION} (c) nicholas a. evans"
    banner <<-EOS
qless-pool is the best way to manage a group (pool) of qless workers

When daemonized, stdout and stderr default to qless-pool.stdxxx.log files in
the log directory and pidfile defaults to qless-pool.pid in the current dir.

Usage:
   qless-pool [options]
where [options] are:
    EOS
    opt :config, "Alternate path to config file", :type => String, :short => "-c"
    opt :appname, "Alternate appname",         :type => String,    :short => "-a"
    opt :daemon, "Run as a background daemon", :default => false,  :short => "-d"
    opt :stdout, "Redirect stdout to logfile", :type => String,    :short => '-o'
    opt :stderr, "Redirect stderr to logfile", :type => String,    :short => '-e'
    opt :nosync, "Don't sync logfiles on every write"
    opt :pidfile, "PID file location",         :type => String,    :short => "-p"
    opt :environment, "Set RAILS_ENV/RACK_ENV/QLESS_ENV", :type => String, :short => "-E"
    opt :term_graceful_wait, "On TERM signal, wait for workers to shut down gracefully"
    opt :term_graceful,      "On TERM signal, shut down workers gracefully"
    opt :term_immediate,     "On TERM signal, shut down workers immediately (default)"
  end
  if opts[:daemon]
    opts[:stdout]  ||= "log/qless-pool.stdout.log"
    opts[:stderr]  ||= "log/qless-pool.stderr.log"
    opts[:pidfile] ||= "tmp/pids/qless-pool.pid"
  end
  opts
end

#process_still_running?(pidfile) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/qless/pool/cli.rb', line 83

def process_still_running?(pidfile)
  old_pid = open(pidfile).read.strip.to_i
  Process.kill 0, old_pid
  true
rescue Errno::ESRCH
  false
rescue Errno::EPERM
  true
rescue ::Exception => e
  $stderr.puts "While checking if PID #{old_pid} is running, unexpected #{e.class}: #{e}"
  true
end

#redirect(opts) ⇒ Object 



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# File 'lib/qless/pool/cli.rb', line 96

def redirect(opts)
  $stdin.reopen  '/dev/null'        if opts[:daemon]
  # need to reopen as File, or else Qless::Pool::Logging.reopen_logs! won't work
  out = File.new(opts[:stdout], "a") if opts[:stdout] && !opts[:stdout].empty?
  err = File.new(opts[:stderr], "a") if opts[:stderr] && !opts[:stderr].empty?
  $stdout.reopen out if out
  $stderr.reopen err if err
  $stdout.sync = $stderr.sync = true unless opts[:nosync]
end

#run ⇒ Object 



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# File 'lib/qless/pool/cli.rb', line 10

def run
  opts = parse_options
  daemonize if opts[:daemon]
  manage_pidfile opts[:pidfile]
  redirect opts
  setup_environment opts
  set_pool_options opts
  start_pool
end

#set_pool_options(opts) ⇒ Object

TODO: global variables are not the best way



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# File 'lib/qless/pool/cli.rb', line 107

def set_pool_options(opts)
  if opts[:daemon]
    Qless::Pool.handle_winch = true
  end
  if opts[:term_graceful_wait]
    Qless::Pool.term_behavior = "graceful_worker_shutdown_and_wait"
  elsif opts[:term_graceful]
    Qless::Pool.term_behavior = "graceful_worker_shutdown"
  end
end

#setup_environment(opts) ⇒ Object 



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# File 'lib/qless/pool/cli.rb', line 118

def setup_environment(opts)
  Qless::Pool.app_name = opts[:appname]    if opts[:appname]
  ENV["RAILS_ENV"] ||= 'development'
  ENV["RACK_ENV"] = ENV["RAILS_ENV"] = ENV["QLESS_ENV"] = opts[:environment] if opts[:environment]
  Qless::Pool.log "Qless Pool running in #{ENV["RAILS_ENV"]} environment"
  ENV["QLESS_POOL_CONFIG"] = opts[:config] if opts[:config]
end

#start_pool ⇒ Object 



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# File 'lib/qless/pool/cli.rb', line 126

def start_pool
  require 'rake'
  require 'qless/pool/tasks'
  Rake.application.init
  Rake.application.load_rakefile
  Rake.application["qless:pool"].invoke
end