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Python tests: Daemon ported to Windows

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Instead of using os.fork (not supported on Windows),
subprocess.Popen is used and os.pipe was replaced
with Windows pipes.

To be able to identify the child process, an extra
parameter was added to daemon process '--pipe-handle'.
This parameter contains the parent Windows pipe handle
which is used by the child to notify the parent about
the startup.

The PID file is created directly on Windows, without
using a temporary file because the symbolic link does
not inherit the file lok set on the temporary file.

Signed-off-by: Paul-Daniel Boca <pboca@cloudbasesolutions.com>
Signed-off-by: Alin Balutoiu <abalutoiu@cloudbasesolutions.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions>
Tested-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions>
Signed-off-by: Gurucharan Shetty <guru@ovn.org>
This commit is contained in:
Alin Balutoiu
2017-01-03 20:10:52 +00:00
committed by Gurucharan Shetty
parent 03947eb7ec
commit 9e03d7344c
4 changed files with 199 additions and 38 deletions
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194
python/ovs/daemon.py
View File

@@ -13,9 +13,7 @@
# limitations under the License.
import errno
import fcntl
import os
import resource
import signal
import sys
import time
@@ -28,11 +26,24 @@ import ovs.timeval
import ovs.util
import ovs.vlog
if sys.platform != 'win32':
import fcntl
import resource
else:
import ovs.winutils as winutils
import ovs.fcntl_win as fcntl
import pywintypes
import subprocess
import win32process
vlog = ovs.vlog.Vlog("daemon")
# --detach: Should we run in the background?
_detach = False
# Running as the child process - Windows only.
_detached = False
# --pidfile: Name of pidfile (null if none).
_pidfile = None
@@ -98,6 +109,16 @@ def set_detach():
_detach = True
def set_detached(wp):
"""Sets up a following call to daemonize() to fork a supervisory
process to monitor the daemon and restart it if it dies due to
an error signal. Used on Windows only."""
global _detached
global _daemonize_fd
_detached = True
_daemonize_fd = int(wp)
def get_detach():
"""Will daemonize() really detach?"""
return _detach
@@ -123,8 +144,12 @@ def _make_pidfile():
pid = os.getpid()
# Create a temporary pidfile.
tmpfile = "%s.tmp%d" % (_pidfile, pid)
ovs.fatal_signal.add_file_to_unlink(tmpfile)
if sys.platform != 'win32':
tmpfile = "%s.tmp%d" % (_pidfile, pid)
ovs.fatal_signal.add_file_to_unlink(tmpfile)
else:
tmpfile = "%s" % _pidfile
try:
# This is global to keep Python from garbage-collecting and
# therefore closing our file after this function exits. That would
@@ -147,40 +172,48 @@ def _make_pidfile():
_fatal("%s: write failed: %s" % (tmpfile, e.strerror))
try:
fcntl.lockf(file_handle, fcntl.LOCK_EX | fcntl.LOCK_NB)
if sys.platform != 'win32':
fcntl.lockf(file_handle, fcntl.LOCK_EX | fcntl.LOCK_NB)
else:
fcntl.lockf(file_handle, fcntl.LOCK_SH | fcntl.LOCK_NB)
except IOError as e:
_fatal("%s: fcntl failed: %s" % (tmpfile, e.strerror))
# Rename or link it to the correct name.
if _overwrite_pidfile:
try:
os.rename(tmpfile, _pidfile)
except OSError as e:
_fatal("failed to rename \"%s\" to \"%s\" (%s)"
% (tmpfile, _pidfile, e.strerror))
if sys.platform == 'win32':
# Ensure that the pidfile will gets closed and deleted on exit.
ovs.fatal_signal.add_file_to_close_and_unlink(_pidfile, file_handle)
else:
while True:
# Rename or link it to the correct name.
if _overwrite_pidfile:
try:
os.link(tmpfile, _pidfile)
error = 0
os.rename(tmpfile, _pidfile)
except OSError as e:
error = e.errno
if error == errno.EEXIST:
_check_already_running()
elif error != errno.EINTR:
break
if error:
_fatal("failed to link \"%s\" as \"%s\" (%s)"
% (tmpfile, _pidfile, os.strerror(error)))
_fatal("failed to rename \"%s\" to \"%s\" (%s)"
% (tmpfile, _pidfile, e.strerror))
else:
while True:
try:
os.link(tmpfile, _pidfile)
error = 0
except OSError as e:
error = e.errno
if error == errno.EEXIST:
_check_already_running()
elif error != errno.EINTR:
break
if error:
_fatal("failed to link \"%s\" as \"%s\" (%s)"
% (tmpfile, _pidfile, os.strerror(error)))
# Ensure that the pidfile will get deleted on exit.
ovs.fatal_signal.add_file_to_unlink(_pidfile)
# Ensure that the pidfile will get deleted on exit.
ovs.fatal_signal.add_file_to_unlink(_pidfile)
# Delete the temporary pidfile if it still exists.
if not _overwrite_pidfile:
error = ovs.fatal_signal.unlink_file_now(tmpfile)
if error:
_fatal("%s: unlink failed (%s)" % (tmpfile, os.strerror(error)))
# Delete the temporary pidfile if it still exists.
if not _overwrite_pidfile:
error = ovs.fatal_signal.unlink_file_now(tmpfile)
if error:
_fatal("%s: unlink failed (%s)" % (
tmpfile, os.strerror(error)))
global _pidfile_dev
global _pidfile_ino
@@ -206,6 +239,9 @@ def _waitpid(pid, options):
def _fork_and_wait_for_startup():
if sys.platform == 'win32':
return _fork_and_wait_for_startup_windows()
try:
rfd, wfd = os.pipe()
except OSError as e:
@@ -259,7 +295,65 @@ def _fork_and_wait_for_startup():
return pid
def _fork_and_wait_for_startup_windows():
global _detached
if _detached:
# Running in child process
ovs.timeval.postfork()
return 0
""" close the log file, on Windows cannot be moved while the parent has
a reference on it."""
vlog.close_log_file()
try:
(rfd, wfd) = winutils.windows_create_pipe()
except pywintypes.error as e:
sys.stderr.write("pipe failed to create: %s\n" % e.strerror)
sys.exit(1)
try:
creationFlags = win32process.DETACHED_PROCESS
args = ("%s %s --pipe-handle=%ld" % (
sys.executable, " ".join(sys.argv), int(wfd)))
proc = subprocess.Popen(
args=args,
close_fds=False,
shell=False,
creationflags=creationFlags,
stdout=sys.stdout,
stderr=sys.stderr)
pid = proc.pid
except OSError as e:
sys.stderr.write("CreateProcess failed (%s)\n" % os.strerror(e.errno))
sys.exit(1)
# Running in parent process.
winutils.win32file.CloseHandle(wfd)
ovs.fatal_signal.fork()
error, s = winutils.windows_read_pipe(rfd, 1)
if error:
s = ""
if len(s) != 1:
retval = proc.wait()
if retval == 0:
sys.stderr.write("fork child failed to signal startup\n")
else:
# Child exited with an error. Convey the same error to
# our parent process as a courtesy.
sys.exit(retval)
winutils.win32file.CloseHandle(rfd)
return pid
def _fork_notify_startup(fd):
if sys.platform == 'win32':
_fork_notify_startup_windows(fd)
return
if fd is not None:
error, bytes_written = ovs.socket_util.write_fully(fd, "0")
if error:
@@ -268,9 +362,31 @@ def _fork_notify_startup(fd):
os.close(fd)
def _fork_notify_startup_windows(fd):
if fd is not None:
try:
# Python 2 requires a string as second parameter, while
# Python 3 requires a bytes-like object. b"0" fits for both
# python versions.
winutils.win32file.WriteFile(fd, b"0", None)
except winutils.pywintypes.error as e:
sys.stderr.write("could not write to pipe: %s\n" %
os.strerror(e.winerror))
sys.exit(1)
def _should_restart(status):
global RESTART_EXIT_CODE
if sys.platform == 'win32':
# The exit status is encoded in the high byte of the
# 16-bit number 'status'.
exit_status = status >> 8
if exit_status == RESTART_EXIT_CODE:
return True
return False
if os.WIFEXITED(status) and os.WEXITSTATUS(status) == RESTART_EXIT_CODE:
return True
@@ -296,7 +412,7 @@ def _monitor_daemon(daemon_pid):
% (daemon_pid, ovs.process.status_msg(status)))
if _should_restart(status):
if os.WCOREDUMP(status):
if sys.platform != 'win32' and os.WCOREDUMP(status):
# Disable further core dumps to save disk space.
try:
resource.setrlimit(resource.RLIMIT_CORE, (0, 0))
@@ -351,8 +467,9 @@ def daemonize_start():
# Running in parent process.
sys.exit(0)
# Running in daemon or monitor process.
os.setsid()
if sys.platform != 'win32':
# Running in daemon or monitor process.
os.setsid()
if _monitor:
saved_daemonize_fd = _daemonize_fd
@@ -360,7 +477,8 @@ def daemonize_start():
if daemon_pid > 0:
# Running in monitor process.
_fork_notify_startup(saved_daemonize_fd)
_close_standard_fds()
if sys.platform != 'win32':
_close_standard_fds()
_monitor_daemon(daemon_pid)
# Running in daemon process
@@ -502,6 +620,10 @@ def add_args(parser):
help="Create pidfile (default %s)." % pidfile)
group.add_argument("--overwrite-pidfile", action="store_true",
help="With --pidfile, start even if already running.")
if sys.platform == 'win32':
group.add_argument("--pipe-handle",
help=("With --pidfile, start even if "
"already running."))
def handle_args(args):
@@ -510,6 +632,10 @@ def handle_args(args):
parent ArgumentParser should have been prepared by add_args() before
calling parse_args()."""
if sys.platform == 'win32':
if args.pipe_handle:
set_detached(args.pipe_handle)
if args.detach:
set_detach()

13
python/ovs/fatal_signal.py
View File

@@ -59,6 +59,17 @@ def add_file_to_unlink(file):
_files[file] = None
def add_file_to_close_and_unlink(file, fd=None):
"""Registers 'file' to be unlinked when the program terminates via
sys.exit() or a fatal signal and the 'fd' to be closed. On Windows a file
cannot be removed while it is open for writing."""
global _added_hook
if not _added_hook:
_added_hook = True
add_hook(_unlink_files, _cancel_files, True)
_files[file] = fd
def remove_file_to_unlink(file):
"""Unregisters 'file' from being unlinked when the program terminates via
sys.exit() or a fatal signal."""
@@ -78,6 +89,8 @@ def unlink_file_now(file):
def _unlink_files():
for file_ in _files:
if sys.platform == "win32" and _files[file_]:
_files[file_].close()
_unlink(file_)

26
python/ovs/vlog.py
View File

@@ -243,7 +243,14 @@ class Vlog(object):
Vlog._unixctl_vlog_reopen, None)
ovs.unixctl.command_register("vlog/close", "", 0, 0,
Vlog._unixctl_vlog_close, None)
ovs.unixctl.command_register("vlog/set", "spec", 1, sys.maxsize,
try:
# Windows limitation on Python 2, sys.maxsize is a long number
# on 64 bits environments, while sys.maxint is the maximum int
# number. Python 3 works as expected.
maxsize_int = sys.maxint
except AttributeError:
maxsize_int = sys.maxsize
ovs.unixctl.command_register("vlog/set", "spec", 1, maxsize_int,
Vlog._unixctl_vlog_set, None)
ovs.unixctl.command_register("vlog/list", "", 0, 0,
Vlog._unixctl_vlog_list, None)
@@ -383,6 +390,16 @@ class Vlog(object):
Vlog.__file_handler = logging.FileHandler(Vlog.__log_file)
logger.addHandler(Vlog.__file_handler)
@staticmethod
def close_log_file():
"""Closes the current log file. (This is useful on Windows, to ensure
that a reference to the file is not kept by the daemon in case of
detach.)"""
if Vlog.__log_file:
logger = logging.getLogger("file")
logger.removeHandler(Vlog.__file_handler)
Vlog.__file_handler.close()
@staticmethod
def _unixctl_vlog_reopen(conn, unused_argv, unused_aux):
if Vlog.__log_file:
@@ -394,8 +411,11 @@ class Vlog(object):
@staticmethod
def _unixctl_vlog_close(conn, unused_argv, unused_aux):
if Vlog.__log_file:
logger = logging.getLogger("file")
logger.removeHandler(Vlog.__file_handler)
if sys.platform != 'win32':
logger = logging.getLogger("file")
logger.removeHandler(Vlog.__file_handler)
else:
Vlog.close_log_file()
conn.reply(None)
@staticmethod