| Current File : //lib/python2.7/site-packages/cloudinit/config/cc_power_state_change.py |
# Copyright (C) 2011 Canonical Ltd.
#
# Author: Scott Moser <scott.moser@canonical.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
"""
Power State Change
------------------
**Summary:** change power state
This module handles shutdown/reboot after all config modules have been run. By
default it will take no action, and the system will keep running unless a
package installation/upgrade requires a system reboot (e.g. installing a new
kernel) and ``package_reboot_if_required`` is true. The ``power_state`` config
key accepts a dict of options. If ``mode`` is any value other than
``poweroff``, ``halt``, or ``reboot``, then no action will be taken.
The system
can be shutdown before cloud-init has finished using the ``timeout`` option.
The ``delay`` key specifies a duration to be added onto any shutdown command
used. Therefore, if a 5 minute delay and a 120 second shutdown are specified,
the maximum amount of time between cloud-init starting and the system shutting
down is 7 minutes, and the minimum amount of time is 5 minutes. The ``delay``
key must have an argument in a form that the ``shutdown`` utility recognizes.
The most common format is the form ``+5`` for 5 minutes. See ``man shutdown``
for more options.
Optionally, a command can be run to determine whether or not
the system should shut down. The command to be run should be specified in the
``condition`` key. For command formatting, see the documentation for
``cc_runcmd``. The specified shutdown behavior will only take place if the
``condition`` key is omitted or the command specified by the ``condition``
key returns 0.
**Internal name:** ``cc_power_state_change``
**Module frequency:** per instance
**Supported distros:** all
**Config keys**::
power_state:
delay: <now/'+minutes'>
mode: <poweroff/halt/reboot>
message: <shutdown message>
timeout: <seconds>
condition: <true/false/command>
"""
from cloudinit.settings import PER_INSTANCE
from cloudinit import util
import errno
import os
import re
import six
import subprocess
import time
frequency = PER_INSTANCE
EXIT_FAIL = 254
def givecmdline(pid):
# Returns the cmdline for the given process id. In Linux we can use procfs
# for this but on BSD there is /usr/bin/procstat.
try:
# Example output from procstat -c 1
# PID COMM ARGS
# 1 init /bin/init --
if util.is_FreeBSD():
(output, _err) = util.subp(['procstat', '-c', str(pid)])
line = output.splitlines()[1]
m = re.search(r'\d+ (\w|\.|-)+\s+(/\w.+)', line)
return m.group(2)
else:
return util.load_file("/proc/%s/cmdline" % pid)
except IOError:
return None
def check_condition(cond, log=None):
if isinstance(cond, bool):
if log:
log.debug("Static Condition: %s" % cond)
return cond
pre = "check_condition command (%s): " % cond
try:
proc = subprocess.Popen(cond, shell=not isinstance(cond, list))
proc.communicate()
ret = proc.returncode
if ret == 0:
if log:
log.debug(pre + "exited 0. condition met.")
return True
elif ret == 1:
if log:
log.debug(pre + "exited 1. condition not met.")
return False
else:
if log:
log.warning(pre + "unexpected exit %s. " % ret +
"do not apply change.")
return False
except Exception as e:
if log:
log.warning(pre + "Unexpected error: %s" % e)
return False
def handle(_name, cfg, _cloud, log, _args):
try:
(args, timeout, condition) = load_power_state(cfg)
if args is None:
log.debug("no power_state provided. doing nothing")
return
except Exception as e:
log.warning("%s Not performing power state change!" % str(e))
return
if condition is False:
log.debug("Condition was false. Will not perform state change.")
return
mypid = os.getpid()
cmdline = givecmdline(mypid)
if not cmdline:
log.warning("power_state: failed to get cmdline of current process")
return
devnull_fp = open(os.devnull, "w")
log.debug("After pid %s ends, will execute: %s" % (mypid, ' '.join(args)))
util.fork_cb(run_after_pid_gone, mypid, cmdline, timeout, log,
condition, execmd, [args, devnull_fp])
def load_power_state(cfg):
# returns a tuple of shutdown_command, timeout
# shutdown_command is None if no config found
pstate = cfg.get('power_state')
if pstate is None:
return (None, None, None)
if not isinstance(pstate, dict):
raise TypeError("power_state is not a dict.")
opt_map = {'halt': '-H', 'poweroff': '-P', 'reboot': '-r'}
mode = pstate.get("mode")
if mode not in opt_map:
raise TypeError(
"power_state[mode] required, must be one of: %s. found: '%s'." %
(','.join(opt_map.keys()), mode))
delay = pstate.get("delay", "now")
# convert integer 30 or string '30' to '+30'
try:
delay = "+%s" % int(delay)
except ValueError:
pass
if delay != "now" and not re.match(r"\+[0-9]+", delay):
raise TypeError(
"power_state[delay] must be 'now' or '+m' (minutes)."
" found '%s'." % delay)
args = ["shutdown", opt_map[mode], delay]
if pstate.get("message"):
args.append(pstate.get("message"))
try:
timeout = float(pstate.get('timeout', 30.0))
except ValueError:
raise ValueError("failed to convert timeout '%s' to float." %
pstate['timeout'])
condition = pstate.get("condition", True)
if not isinstance(condition, six.string_types + (list, bool)):
raise TypeError("condition type %s invalid. must be list, bool, str")
return (args, timeout, condition)
def doexit(sysexit):
os._exit(sysexit)
def execmd(exe_args, output=None, data_in=None):
ret = 1
try:
proc = subprocess.Popen(exe_args, stdin=subprocess.PIPE,
stdout=output, stderr=subprocess.STDOUT)
proc.communicate(data_in)
ret = proc.returncode
except Exception:
doexit(EXIT_FAIL)
doexit(ret)
def run_after_pid_gone(pid, pidcmdline, timeout, log, condition, func, args):
# wait until pid, with /proc/pid/cmdline contents of pidcmdline
# is no longer alive. After it is gone, or timeout has passed
# execute func(args)
msg = None
end_time = time.time() + timeout
def fatal(msg):
if log:
log.warning(msg)
doexit(EXIT_FAIL)
known_errnos = (errno.ENOENT, errno.ESRCH)
while True:
if time.time() > end_time:
msg = "timeout reached before %s ended" % pid
break
try:
cmdline = givecmdline(pid)
if cmdline != pidcmdline:
msg = "cmdline changed for %s [now: %s]" % (pid, cmdline)
break
except IOError as ioerr:
if ioerr.errno in known_errnos:
msg = "pidfile gone [%d]" % ioerr.errno
else:
fatal("IOError during wait: %s" % ioerr)
break
except Exception as e:
fatal("Unexpected Exception: %s" % e)
time.sleep(.25)
if not msg:
fatal("Unexpected error in run_after_pid_gone")
if log:
log.debug(msg)
try:
if not check_condition(condition, log):
return
except Exception as e:
fatal("Unexpected Exception when checking condition: %s" % e)
func(*args)
# vi: ts=4 expandtab