On 7/28/20 8:42 AM, Vladimir Sementsov-Ogievskiy wrote:
28.07.2020 00:58, Nir Soffer wrote:
Instead of duplicating the code to wait until the server is ready and
remember to terminate the server and wait for it, make it possible to
use like this:
with qemu_nbd_popen('-k', sock, image):
# Access image via qemu-nbd socket...
Only test 264 used this helper, but I had to modify the output since it
did not consistently when starting and stopping qemu-nbd.
Signed-off-by: Nir Soffer <nsof...@redhat.com>
---
+++ b/tests/qemu-iotests/iotests.py
@@ -28,10 +28,13 @@ import signal
import struct
import subprocess
import sys
+import time
from typing import (Any, Callable, Dict, Iterable,
List, Optional, Sequence, Tuple, TypeVar)
import unittest
+from contextlib import contextmanager
+
# pylint: disable=import-error, wrong-import-position
sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..',
'python'))
from qemu import qtest
@@ -270,9 +273,30 @@ def qemu_nbd_early_pipe(*args):
return subp.returncode, output if subp.returncode else ''
+@contextmanager
def qemu_nbd_popen(*args):
- '''Run qemu-nbd in daemon mode and return the parent's exit code'''
- return subprocess.Popen(qemu_nbd_args + ['--persistent'] +
list(args))
+ '''Context manager running qemu-nbd within the context'''
PEP8 (or some another PEP referenced in PEP8) asks to use """ for
doc-strings
But at least './check 297' still passes, so we are consistent enough
with our current set of syntax checks to be acceptable.
+ pid_file = file_path("pid")
+
+ cmd = list(qemu_nbd_args)
+ cmd.extend(('--persistent', '--pid-file', pid_file))
+ cmd.extend(args)
+
+ log('Start NBD server')
+ p = subprocess.Popen(cmd)
+ try:
+ while not os.path.exists(pid_file):
+ if p.poll() is not None:
+ raise RuntimeError(
+ "qemu-nbd terminated with exit code {}: {}"
+ .format(p.returncode, ' '.join(cmd)))
+
+ time.sleep(0.01)
+ yield
+ finally:
+ log('Kill NBD server')
+ p.kill()
+ p.wait()
why do we need try-finally? I think, the only possible exception is your
"raise RuntimeError", and in this case the process is alredy dead, no
need to kill it (and print the log message)
def compare_images(img1, img2, fmt1=imgfmt, fmt2=imgfmt):
'''Return True if two image files are identical'''
anyway:
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Thanks; I trust your python review more than mine. Queuing for -rc2.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org