Restore SIGPIPE default action for subprocesses

Code Issues Proposed changes

Python ignores SIGPIPE on startup, because it prefers to check every
write and raise an IOError exception rather than taking the signal. Most
Unix subprocesses don't expect to work this way. This patch (adapted
from Colin Watson's post at http://tinyurl.com/2a7mzh5) sets SIGPIPE
back to the default action for nova.utils.execute and nova-rootwrap
created subprocesses.
Fixes bug 1053364
Change-Id: I17e1629bb4ef4268515c6734ddb6e12746739c52

This commit is contained in:

Thierry Carrez

2012年09月20日 14:11:38 +02:00

parent 59ad151a29

commit a694b9e5ad

2 changed files with 17 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

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9
bin/nova-rootwrap

View File

@@ -34,6 +34,7 @@

import ConfigParser

import os

import signal

import subprocess

import sys

@@ -42,6 +43,13 @@ RC_UNAUTHORIZED = 99

RC_NOCOMMAND = 98

RC_BADCONFIG = 97

def _subprocess_setup():

# Python installs a SIGPIPE handler by default. This is usually not what

# non-Python subprocesses expect.

signal.signal(signal.SIGPIPE, signal.SIG_DFL)

if __name__ == '__main__':

# Split arguments, require at least a command

execname = sys.argv.pop(0)

@@ -77,6 +85,7 @@ if __name__ == '__main__':

stdin=sys.stdin,

stdout=sys.stdout,

stderr=sys.stderr,

preexec_fn=_subprocess_setup,

env=filtermatch.get_environment(userargs))

obj.wait()

sys.exit(obj.returncode)

8
nova/utils.py

View File

@@ -31,6 +31,7 @@ import random

import re

import shlex

import shutil

import signal

import socket

import struct

import sys

@@ -112,6 +113,12 @@ def vpn_ping(address, port, timeout=0.05, session_id=None):

return server_sess

def _subprocess_setup():

# Python installs a SIGPIPE handler by default. This is usually not what

# non-Python subprocesses expect.

signal.signal(signal.SIGPIPE, signal.SIG_DFL)

def execute(*cmd, **kwargs):

"""Helper method to execute command with optional retry.

@@ -180,6 +187,7 @@ def execute(*cmd, **kwargs):

stdout=_PIPE,

stderr=_PIPE,

close_fds=True,

preexec_fn=_subprocess_setup,

shell=shell)

result = None

if process_input is not None: