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✏️ Editing: signal_handler.py

# Copyright (C) 2012 Canonical Ltd.
# Copyright (C) 2012 Yahoo! Inc.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Joshua Harlow <harlowja@yahoo-inc.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
import inspect
import logging
import signal
import sys
from io import StringIO

from cloudinit import util
from cloudinit import version as vr

LOG = logging.getLogger(__name__)

BACK_FRAME_TRACE_DEPTH = 3
EXIT_FOR = {
    signal.SIGINT: ("Cloud-init %(version)s received SIGINT, exiting...", 1),
    signal.SIGTERM: ("Cloud-init %(version)s received SIGTERM, exiting...", 1),
    # Can't be caught...
    # signal.SIGKILL: ('Cloud-init killed, exiting...', 1),
    signal.SIGABRT: ("Cloud-init %(version)s received SIGABRT, exiting...", 1),
}

def _pprint_frame(frame, depth, max_depth, contents):
    if depth > max_depth or not frame:
        return
    frame_info = inspect.getframeinfo(frame)
    prefix = " " * (depth * 2)
    contents.write("%sFilename: %s\n" % (prefix, frame_info.filename))
    contents.write("%sFunction: %s\n" % (prefix, frame_info.function))
    contents.write("%sLine number: %s\n" % (prefix, frame_info.lineno))
    _pprint_frame(frame.f_back, depth + 1, max_depth, contents)

def _handle_exit(signum, frame):
    (msg, rc) = EXIT_FOR[signum]
    msg = msg % ({"version": vr.version_string()})
    contents = StringIO()
    contents.write("%s\n" % (msg))
    _pprint_frame(frame, 1, BACK_FRAME_TRACE_DEPTH, contents)
    util.multi_log(contents.getvalue(), console=True, stderr=False, log=LOG)
    sys.exit(rc)

def attach_handlers():
    sigs_attached = 0
    for signum in EXIT_FOR.keys():
        signal.signal(signum, _handle_exit)
    sigs_attached += len(EXIT_FOR)
    return sigs_attached

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