Class: Insidious

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Insidious

Intiailise Insidious, note the correct spelling of initialise.



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# File 'lib/insidious.rb', line 7

def initialize(options = {})
  @daemonize = options[:daemonize].nil? ? true : options[:daemonize]
  @pid_file = options[:pid_file].nil? ? nil : File.absolute_path(options[:pid_file])
end

Instance Attribute Details

#pid_file ⇒ Object (readonly)

Returns the value of attribute pid_file.



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# File 'lib/insidious.rb', line 4

def pid_file
  @pid_file
end

Instance Method Details

#daemon? ⇒ Boolean

Returns true if insidious is running as a daemon which is the default

Returns:

  • (Boolean) 


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# File 'lib/insidious.rb', line 75

def daemon?
  @daemonize
end

#pid ⇒ Object

Get the pid from the pid_file TODO: should this be ‘cached’?



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# File 'lib/insidious.rb', line 81

def pid
  File.read(@pid_file).strip.to_i
end

#pid=(pid) ⇒ Object

Save the PID to the PID file specified in @pid_file



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# File 'lib/insidious.rb', line 86

def pid=(pid)
  File.open(@pid_file, 'w') do |file|
    file.write(pid)
  end if @pid_file
end

#restart!(&block) ⇒ Object

Restarts the daemon, just a convenience method really



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# File 'lib/insidious.rb', line 52

def restart!(&block)
  stop! if running?
  start!(&block)
end

#running? ⇒ Boolean

Returns true if the daemon is running

Returns:

  • (Boolean) 


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# File 'lib/insidious.rb', line 58

def running?
  # First check if we have a pid file and if it exists
  return false if @pid_file.nil? || !File.exists?(@pid_file)

  # Then make sure we have a pid
  return false if pid.nil?

  # If we can get the process id then we assume it is running
  begin
    Process.getpgid(pid)
    true
  rescue Errno::ESRCH
    false
  end
end

#start!(&block) ⇒ Object

Starts the daemon

If a PID file was provided it will try to store the current PID. If this files exists it will try to check if the stored PID is already running, in which case insidious will exit with an error code.



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# File 'lib/insidious.rb', line 18

def start!(&block)
  if running?
    fail InsidiousError.new("Process is already running with PID #{pid}")
    exit 2
  else
    if @pid_file.nil? && daemon?
      fail InsidiousError.new('No PID file is set but daemonize is set to true')
      exit 1
    end

    run_daemon!(&block)
  end
end

#stop! ⇒ Object

Stops the daemon execution

This method only works when a PID file is given, otherwise it will exit with an error.



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# File 'lib/insidious.rb', line 36

def stop!
  if @pid_file && File.exists?(@pid_file)
    begin
      Process.kill(:INT, pid)
      File.delete(@pid_file)
    rescue Errno::ESRCH
      fail InsidiousError.new("No process is running with PID #{pid}")
      exit 3
    end
  else
    fail InsidiousError.new("Couldn't find the PID file: '#{@pid_file}'")
    exit 1
  end
end