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ansible/utilities/logic/async_wrapper.py

212 lines
6.6 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 traceback
import signal
import time
import syslog
syslog.openlog('ansible-%s' % os.path.basename(__file__))
syslog.syslog(syslog.LOG_NOTICE, 'Invoked with %s' % " ".join(sys.argv[1:]))
def notice(msg):
syslog.syslog(syslog.LOG_NOTICE, msg)
def daemonize_self():
# daemonizing code: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66012
try:
pid = os.fork()
if pid > 0:
# exit first parent
sys.exit(0)
except OSError:
e = sys.exc_info()[1]
sys.exit("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
# decouple from parent environment
os.chdir("/")
os.setsid()
os.umask(int('022', 8))
# do second fork
try:
pid = os.fork()
if pid > 0:
# print "Daemon PID %d" % pid
sys.exit(0)
except OSError:
e = sys.exc_info()[1]
sys.exit("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
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())
def _run_module(wrapped_cmd, jid, job_path):
jobfile = open(job_path, "w")
jobfile.write(json.dumps({ "started" : 1, "ansible_job_id" : jid }))
jobfile.close()
jobfile = open(job_path, "w")
result = {}
outdata = ''
try:
cmd = shlex.split(wrapped_cmd)
script = subprocess.Popen(cmd, shell=False, stdin=None, stdout=jobfile, stderr=jobfile)
script.communicate()
outdata = file(job_path).read()
result = json.loads(outdata)
except (OSError, IOError):
e = sys.exc_info()[1]
result = {
"failed": 1,
"cmd" : wrapped_cmd,
"msg": str(e),
}
result['ansible_job_id'] = jid
jobfile.write(json.dumps(result))
except:
result = {
"failed" : 1,
"cmd" : wrapped_cmd,
"data" : outdata, # temporary notice only
"msg" : traceback.format_exc()
}
result['ansible_job_id'] = jid
jobfile.write(json.dumps(result))
jobfile.close()
####################
## main ##
####################
if __name__ == '__main__':
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 = "%s.%d" % (sys.argv[1], os.getpid())
time_limit = sys.argv[2]
wrapped_module = sys.argv[3]
if len(sys.argv) >= 5:
argsfile = sys.argv[4]
cmd = "%s %s" % (wrapped_module, argsfile)
else:
cmd = wrapped_module
step = 5
# setup job output directory
jobdir = os.path.expanduser("~/.ansible_async")
job_path = os.path.join(jobdir, jid)
if not os.path.exists(jobdir):
try:
os.makedirs(jobdir)
except:
print(json.dumps({
"failed" : 1,
"msg" : "could not create: %s" % jobdir
}))
# immediately exit this process, leaving an orphaned process
# running which immediately forks a supervisory timing process
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
notice("Return async_wrapper task started.")
print(json.dumps({ "started" : 1, "ansible_job_id" : jid, "results_file" : job_path }))
sys.stdout.flush()
time.sleep(1)
sys.exit(0)
else:
# The actual wrapper process
# Daemonize, so we keep on running
daemonize_self()
# we are now daemonized, create a supervisory process
notice("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)
notice("Start watching %s (%s)"%(sub_pid, remaining))
time.sleep(step)
while os.waitpid(sub_pid, os.WNOHANG) == (0, 0):
notice("%s still running (%s)"%(sub_pid, remaining))
time.sleep(step)
remaining = remaining - step
if remaining <= 0:
notice("Now killing %s"%(sub_pid))
os.killpg(sub_pid, signal.SIGKILL)
notice("Sent kill to group %s"%sub_pid)
time.sleep(1)
sys.exit(0)
notice("Done in kid B.")
sys.exit(0)
else:
# the child process runs the actual module
notice("Start module (%s)"%os.getpid())
_run_module(cmd, jid, job_path)
notice("Module complete (%s)"%os.getpid())
sys.exit(0)
except SystemExit:
# On python2.4, SystemExit is a subclass of Exception.
# This block makes python2.4 behave the same as python2.5+
raise
except Exception:
e = sys.exc_info()[1]
notice("error: %s"%(e))
print(json.dumps({
"failed" : True,
"msg" : "FATAL ERROR: %s" % str(e)
}))
sys.exit(1)