ansible/library/internal/async_wrapper
willthames 723af8c370 Ensure async terminates when time limit is not divisible by 5
Because async_wrapper subtracts 5 from time_limit and checks for
equality to zero, values not divisible by 5 will go negative and
continue forever.
2013-11-05 09:42:28 +10:00

200 lines
6 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
# (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>, and others
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible. If not, see <http://www.gnu.org/licenses/>.
#
try:
import json
except ImportError:
import simplejson as json
import shlex
import os
import subprocess
import sys
import datetime
import traceback
import signal
import time
import syslog
def daemonize_self():
# daemonizing code: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66012
# logger.info("cobblerd started")
try:
pid = os.fork()
if pid > 0:
# exit first parent
sys.exit(0)
except OSError, e:
print >>sys.stderr, "fork #1 failed: %d (%s)" % (e.errno, e.strerror)
sys.exit(1)
# decouple from parent environment
os.chdir("/")
os.setsid()
os.umask(022)
# do second fork
try:
pid = os.fork()
if pid > 0:
# print "Daemon PID %d" % pid
sys.exit(0)
except OSError, e:
print >>sys.stderr, "fork #2 failed: %d (%s)" % (e.errno, e.strerror)
sys.exit(1)
dev_null = file('/dev/null','rw')
os.dup2(dev_null.fileno(), sys.stdin.fileno())
os.dup2(dev_null.fileno(), sys.stdout.fileno())
os.dup2(dev_null.fileno(), sys.stderr.fileno())
if len(sys.argv) < 3:
print json.dumps({
"failed" : True,
"msg" : "usage: async_wrapper <jid> <time_limit> <modulescript> <argsfile>. Humans, do not call directly!"
})
sys.exit(1)
jid = sys.argv[1]
time_limit = sys.argv[2]
wrapped_module = sys.argv[3]
argsfile = sys.argv[4]
cmd = "%s %s" % (wrapped_module, argsfile)
syslog.openlog('ansible-%s' % os.path.basename(__file__))
syslog.syslog(syslog.LOG_NOTICE, 'Invoked with %s' % " ".join(sys.argv[1:]))
# setup logging directory
logdir = os.path.expanduser("~/.ansible_async")
log_path = os.path.join(logdir, jid)
if not os.path.exists(logdir):
try:
os.makedirs(logdir)
except:
print json.dumps({
"failed" : 1,
"msg" : "could not create: %s" % logdir
})
def _run_command(wrapped_cmd, jid, log_path):
logfile = open(log_path, "w")
logfile.write(json.dumps({ "started" : 1, "ansible_job_id" : jid }))
logfile.close()
logfile = open(log_path, "w")
result = {}
outdata = ''
try:
cmd = shlex.split(wrapped_cmd)
script = subprocess.Popen(cmd, shell=False,
stdin=None, stdout=logfile, stderr=logfile)
script.communicate()
outdata = file(log_path).read()
result = json.loads(outdata)
except (OSError, IOError), e:
result = {
"failed": 1,
"cmd" : wrapped_cmd,
"msg": str(e),
}
result['ansible_job_id'] = jid
logfile.write(json.dumps(result))
except:
result = {
"failed" : 1,
"cmd" : wrapped_cmd,
"data" : outdata, # temporary debug only
"msg" : traceback.format_exc()
}
result['ansible_job_id'] = jid
logfile.write(json.dumps(result))
logfile.close()
# immediately exit this process, leaving an orphaned process
# running which immediately forks a supervisory timing process
#import logging
#import logging.handlers
#logger = logging.getLogger("ansible_async")
#logger.setLevel(logging.WARNING)
#logger.addHandler( logging.handlers.SysLogHandler("/dev/log") )
def debug(msg):
#logger.warning(msg)
pass
try:
pid = os.fork()
if pid:
# Notify the overlord that the async process started
# we need to not return immmediately such that the launched command has an attempt
# to initialize PRIOR to ansible trying to clean up the launch directory (and argsfile)
# this probably could be done with some IPC later. Modules should always read
# the argsfile at the very first start of their execution anyway
time.sleep(1)
debug("Return async_wrapper task started.")
print json.dumps({ "started" : 1, "ansible_job_id" : jid, "results_file" : log_path })
sys.stdout.flush()
sys.exit(0)
else:
# The actual wrapper process
# Daemonize, so we keep on running
daemonize_self()
# we are now daemonized, create a supervisory process
debug("Starting module and watcher")
sub_pid = os.fork()
if sub_pid:
# the parent stops the process after the time limit
remaining = int(time_limit)
# set the child process group id to kill all children
os.setpgid(sub_pid, sub_pid)
debug("Start watching %s (%s)"%(sub_pid, remaining))
time.sleep(5)
while os.waitpid(sub_pid, os.WNOHANG) == (0, 0):
debug("%s still running (%s)"%(sub_pid, remaining))
time.sleep(5)
remaining = remaining - 5
if remaining <= 0:
debug("Now killing %s"%(sub_pid))
os.killpg(sub_pid, signal.SIGKILL)
debug("Sent kill to group %s"%sub_pid)
time.sleep(1)
sys.exit(0)
debug("Done in kid B.")
os._exit(0)
else:
# the child process runs the actual module
debug("Start module (%s)"%os.getpid())
_run_command(cmd, jid, log_path)
debug("Module complete (%s)"%os.getpid())
sys.exit(0)
except Exception, err:
debug("error: %s"%(err))
raise err