Class: ProcessWanker::ProcessService

Inherits:
Service
  • Object
show all
Includes:
Log
Defined in:
lib/service_classes/process_service.rb

Direct Known Subclasses

PIDService

Constant Summary

Constants included from Log

Log::DEBUG, Log::ERROR, Log::INFO, Log::WARN

Instance Attribute Summary

Attributes inherited from Service

#attempt_count, #config_node, #current_state, #dependencies, #ignore, #last_action_time, #last_fail_time, #last_transition_time, #params, #prev_state, #show_state, #stable, #suppress, #want_state, #want_state_mode

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Log

debug, error, info, log, set_level, warn

Methods inherited from Service

#check_action_delay, #extract_params, #group_name, #matches_single, #matches_spec, #name, #resolve_dependencies, #safe_do, #safe_do_ping, #safe_do_start, #safe_do_stop, #set_want_state, #tick, #validate_params

Constructor Details

#initialize(iparams) ⇒ ProcessService

iparams is a hash containing:

:start_cmd
:start_dir (optional)
:stop_cmd (optional)
:run_user (optional)
:soft_kill_limit (optional)

plus anything to be passed to Service



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# File 'lib/service_classes/process_service.rb', line 44

def initialize(iparams)

# extract parameters
extract_params(
	iparams,
	[
		:start_cmd,
		:start_dir,
		:stop_cmd,
		:run_user,
		:soft_kill_limit,
	])
	
# set defaults
	@params=
	{
		:soft_kill_limit		=>		3,
		:start_dir 					=> 		"/"
	}.merge(@params)

raise "service has no start_cmd" if(!@params[:start_cmd])

# determine run_user properties
if(@params[:run_user])
	if(@params[:run_user].class == String)
		@params[:run_user]=Etc.getpwnam(@params[:run_user])
	elsif(@params[:run_user].class == Fixnum)
		@params[:run_user]=Etc.getpwuid(@params[:run_user].to_i)
	else
		raise "bad run_user parameter for process_service"
	end

	# verify we can switch to this uid if necessary
	current_uid=Process.euid()
	if(current_uid != 0 && current_uid != @params[:run_user].uid)
		raise "can't have a :run_user parameter unless we are running as root, or the uids match"
	end
	
end

  super(iparams)    
end

Class Method Details

.nice_name ⇒ Object 



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# File 'lib/service_classes/process_service.rb', line 26

def self.nice_name
	"process_service"
end

Instance Method Details

#do_ping ⇒ Object

ping

return run state of process



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# File 'lib/service_classes/process_service.rb', line 182

def do_ping
ProcessUtil::processes[env_hash] ? :up : :down	  
end

#do_start(attempt_count) ⇒ Object

start

fork() and exec() the start_cmd



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# File 'lib/service_classes/process_service.rb', line 95

def do_start(attempt_count)
  info("do_start[#{attempt_count}] for #{self.name}")
  
  Process.fork do

	# close network descriptors
	NetUtil::post_fork()

	# start new session
	Process.setsid()

	# set environment cookie so we can be identified		
	hash=env_hash()
	ENV[ ProcessUtil::ENVIRONMENT_KEY ] = hash if(hash)
	
	# change user/group?
	if(@params[:run_user])

		current_uid=Process.euid()
		current_user=Etc.getpwuid(current_uid)
		
		if(current_uid != @params[:run_user].uid)
			Process.uid=@params[:run_user].uid
			Process.gid=@params[:run_user].gid
			Process.euid=@params[:run_user].uid
			Process.egid=@params[:run_user].gid
			ENV["HOME"]=@params[:run_user].dir
		end					
		
	end
	
	# change directory?
	Dir.chdir(@params[:start_dir])
  
	# redirect inputs/outputs
	STDIN.reopen("/dev/null")		# - closing STDIN causes problems with apache
	file=@params[:log_file] ? @params[:log_file] : "/dev/null"
	STDOUT.reopen(file,"a")
	STDERR.reopen(file,"a")
  
  	# run!
  	Process.exec(@params[:start_cmd])
   
  end
  
end

#do_stop(attempt_count) ⇒ Object

stop

stop the process (either with -TERM or -KILL)



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# File 'lib/service_classes/process_service.rb', line 150

def do_stop(attempt_count)

	kl=@params[:soft_kill_limit]
	mode = (kl && attempt_count >= kl) ? :hard : :soft

  info("do_stop[#{attempt_count}]->#{mode} for #{self.name}")
  
if(mode == :soft)
	if(params[:stop_cmd])
		system(params[:stop_cmd])
		return
	end
end	    
  
  # find all processes with matching hash
  procs=ProcessUtil::processes[ env_hash ]
  if(procs)
	procs.each do |pid|
		Process.kill({ :hard => "KILL", :soft => "TERM" }[mode],pid)
	end
  end
	   
end

#env_hash ⇒ Object

env_hash

returns magic environment cookie that identifies processes belonging to this service.



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# File 'lib/service_classes/process_service.rb', line 195

def env_hash()
	Digest::MD5.hexdigest( name )
end