Class: God::Conditions::ProcessExits

Inherits:
EventCondition show all
Defined in:
lib/god/conditions/process_exits.rb

Overview

Condition Symbol :process_exits Type: Event

Trigger when a process exits.

Paramaters

Required
  +pid_file+ is the pid file of the process in question. Automatically
             populated for Watches.

Examples

Trigger if process exits (from a Watch):

on.condition(:process_exits)

Trigger if process exits:

on.condition(:process_exits) do |c|
  c.pid_file = "/var/run/mongrel.3000.pid"
end

Instance Attribute Summary collapse

Attributes inherited from God::Condition

#info, #notify, #phase, #transition

Attributes inherited from Behavior

#watch

Instance Method Summary collapse

Methods inherited from God::Condition

#friendly_name, generate, valid?

Methods inherited from Behavior

#after_restart, #after_start, #after_stop, #before_restart, #before_start, #before_stop, #friendly_name, generate

Methods included from God::Configurable

#base_name, complain, #complain, #friendly_name, #prepare, #reset

Constructor Details

#initialize ⇒ ProcessExits

Returns a new instance of ProcessExits.



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# File 'lib/god/conditions/process_exits.rb', line 28

def initialize
  self.info = "process exited"
end

Instance Attribute Details

#pid_file ⇒ Object

Returns the value of attribute pid_file.



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# File 'lib/god/conditions/process_exits.rb', line 26

def pid_file
  @pid_file
end

Instance Method Details

#deregister ⇒ Object 



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# File 'lib/god/conditions/process_exits.rb', line 57

def deregister
  pid = self.pid
  if pid
    EventHandler.deregister(pid, :proc_exit)
    
    msg = "#{self.watch.name} deregistered 'proc_exit' event for pid #{pid}"
    applog(self.watch, :info, msg)
  else
    pid_file_location = self.pid_file || self.watch.pid_file
    applog(self.watch, :error, "#{self.watch.name} could not deregister: no cached PID or PID file #{pid_file_location} (#{self.base_name})")
  end
end

#pid ⇒ Object 



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# File 'lib/god/conditions/process_exits.rb', line 36

def pid
  self.pid_file ? File.read(self.pid_file).strip.to_i : self.watch.pid
end

#register ⇒ Object 



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# File 'lib/god/conditions/process_exits.rb', line 40

def register
  pid = self.pid
  
  begin
    EventHandler.register(pid, :proc_exit) do |extra|
      formatted_extra = extra.size > 0 ? " #{extra.inspect}" : ""
      self.info = "process #{pid} exited#{formatted_extra}"
      self.watch.trigger(self)
    end
    
    msg = "#{self.watch.name} registered 'proc_exit' event for pid #{pid}"
    applog(self.watch, :info, msg)
  rescue StandardError
    raise EventRegistrationFailedError.new
  end
end

#valid? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/god/conditions/process_exits.rb', line 32

def valid?
  true
end