Class: Pebbles::River::DaemonHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/pebbles/river/daemon_helper.rb

Overview

Simple helper class for easily writing daemons that run multiple queue workers. Handles command line parsing and daemonization.

Adapter should support:

  • ‘name`: Name of the process. Optional, defaults to `$0`.

  • ‘configure_start_command(command)`. Implement to add more options to the start command, eg. configuration options. Optional.

  • ‘on_start(options, helper)`. Implement to inject code before the program starts. Options are the start options, a hash. Optional.

  • ‘configure_supervisor(supervisor)`. This must call `add_listener` on the supervisor to add workers. Required.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(adapter, options = {}) ⇒ DaemonHelper

Returns a new instance of DaemonHelper.



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# File 'lib/pebbles/river/daemon_helper.rb', line 41

def initialize(adapter, options = {})
  @adapter = adapter

  @name = @adapter.name if @adapter.respond_to?(:name)
  @name ||= File.basename($0).gsub(/\.rb$/, '')

  @logger = options.fetch(:logger, Logger.new($stderr))
end

Instance Attribute Details

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/pebbles/river/daemon_helper.rb', line 35

def logger
  @logger
end

Class Method Details

.run(adapter, options = {}) ⇒ Object 



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# File 'lib/pebbles/river/daemon_helper.rb', line 37

def self.run(adapter, options = {})
  new(adapter, options).run
end

Instance Method Details

#run ⇒ Object 



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# File 'lib/pebbles/river/daemon_helper.rb', line 50

def run
  Mercenary.program(@name) do |p|
    p.syntax "#{@name} <subcommand> [OPTION ...]"
    p.command(:start) do |c|
      c.syntax 'start'
      c.description 'Starts daemon'
      c.option :daemonize, '-d', '--daemon', 'To daemonize; otherwise will run synchronously.'
      c.option :pidfile, '-p', '--pidfile PIDFILE', 'Path to pid file.'
      c.option :workers, Integer, '-w', '--workers N', 'Set number of workers per queue (defaults to 1).'
      c.action do |_, options|
        handle_exceptions do
          start(options)
        end
      end
      if @adapter.respond_to?(:configure_start_command)
        @adapter.configure_start_command(c)
      end
    end
    p.command(:stop) do |c|
      c.syntax 'stop'
      c.description 'Stops daemon'
      c.option :pidfile, '-p', '--pidfile PIDFILE', 'Path to pid file.'
      c.action do |_, options|
        handle_exceptions do
          stop(options)
        end
      end
    end
    p.command(:status) do |c|
      c.syntax 'status'
      c.description 'Prints daemon status'
      c.option :pidfile, '-p', '--pidfile PIDFILE', 'Path to pid file.'
      c.action do |_, options|
        handle_exceptions do
          status(options)
        end
      end
    end
  end

  if ARGV.any?
    abort "Unknown command '#{ARGV.first}'."
  else
    abort "Run with -h for help."
  end
end