summaryrefslogtreecommitdiff
path: root/cloudinit/config/cc_power_state_change.py
blob: 7f6e780db60b34d3ffe6624eca9cc52800706117 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
# vi: ts=4 expandtab
#
#    Copyright (C) 2011 Canonical Ltd.
#
#    Author: Scott Moser <scott.moser@canonical.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 3, as
#    published by the Free Software Foundation.
#
#    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

from cloudinit.settings import PER_INSTANCE
from cloudinit import util

import errno
import os
import re
import subprocess
import sys
import time

frequency = PER_INSTANCE


def handle(_name, cfg, _cloud, log, _args):

    try:
        (args, timeout) = load_power_state(cfg)
        if args is None:
            log.debug("no power_state provided. doing nothing")
            return
    except Exception as e:
        log.warn("%s Not performing power state change!" % str(e))
        return

    mypid = os.getpid()
    cmdline = util.load_file("/proc/%s/cmdline" % mypid)

    if not cmdline:
        log.warn("power_state: failed to get cmdline of current process")
        return

    devnull_fp = open("/dev/null", "w")

    log.debug("After pid %s ends, will execute: %s" % (mypid, ' '.join(args)))

    util.fork_cb(run_after_pid_gone, mypid, cmdline, timeout, log, 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)

    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." %
                        ','.join(opt_map.keys()))

    delay = pstate.get("delay", "now")
    if delay != "now" and not re.match("\+[0-9]+", delay):
        raise TypeError("power_state[delay] must be 'now' or '+m' (minutes).")

    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'])

    return (args, timeout)


def execmd(exe_args, output=None, data_in=None):
    try:
        proc = subprocess.Popen(exe_args, stdin=subprocess.PIPE,
                                stdout=output, stderr=subprocess.STDOUT)
        proc.communicate(data_in)
    except Exception:
        sys.exit(254)
    sys.exit(proc.returncode())


def run_after_pid_gone(pid, pidcmdline, timeout, log, 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

    cmdline_f = "/proc/%s/cmdline" % pid

    def fatal(msg):
        if log:
            log.warn(msg)
        sys.exit(254)

    while True:
        if time.time() > end_time:
            msg = "timeout reached before %s ended" % pid
            break

        try:
            cmdline = ""
            with open(cmdline_f) as fp:
                cmdline = fp.read()
            if cmdline != pidcmdline:
                msg = "cmdline changed for %s [now: %s]" % (pid, cmdline)
                break

        except IOError as ioerr:
            if ioerr.errno == errno.ENOENT:
                msg = "pidfile '%s' gone" % cmdline_f
            else:
                fatal("IOError during wait: %s" % ioerr)
            break

        except Exception as e:
            fatal("Unexpected Exception: %s" % e)

    if not msg:
        fatal("Unexpected error in run_after_pid_gone")

    if log:
        log.debug(msg)
    func(*args)