From 75e7e046950464a9dfc1afafeb86fc0b1afe6ce2 Mon Sep 17 00:00:00 2001
From: Stan Lagun <slagun@mirantis.com>
Date: Tue, 22 Mar 2016 16:47:49 +0300
Subject: [PATCH] Restores SIGPIPE on script processes

There is an issue https://bugs.python.org/issue1652
in Python 2.7 which was resolved in Py3.

By default Python sets SIGPIPE to SIG_IGN on startup, because
it prefers to check every write and raise an IOError exception rather
than taking SIGPIPE. This is all well and good for Python itself.
However, non-Python Unix subprocesses generally expect to have
SIGPIPE set to the default action, since that's what will happen if
they're started from a normal shell.

As a result scripts with piping that is terminated in reverse chain
order are never exit.

See more info here:
http://www.enricozini.org/blog/2009/debian/python-pipes/

Closes-Bug: #1524347
Change-Id: Ia015e7fd46912f6a0be97a6b9c297f8d14fd3f7c
---
 muranoagent/executors/application/__init__.py | 20 ++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/muranoagent/executors/application/__init__.py b/muranoagent/executors/application/__init__.py
index 020c9371..64115779 100644
--- a/muranoagent/executors/application/__init__.py
+++ b/muranoagent/executors/application/__init__.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import os
+import signal
 import stat
 import subprocess
 import sys
@@ -52,13 +53,18 @@ class ApplicationExecutor(object):
         script_name = os.path.relpath(self._path)
         LOG.debug("Starting '{0}' script execution".format(script_name))
 
-        process = subprocess.Popen(
-            app,
-            stdout=stdout,
-            stderr=stderr,
-            universal_newlines=True,
-            cwd=dir_name,
-            shell=True)
+        popen_kwargs = {
+            'stdout': stdout,
+            'stderr': stderr,
+            'universal_newlines': True,
+            'cwd': dir_name,
+            'shell': True
+        }
+        if os.name != 'nt':
+            popen_kwargs['preexec_fn'] = lambda: signal.signal(
+                signal.SIGPIPE, signal.SIG_DFL)
+
+        process = subprocess.Popen(app, **popen_kwargs)
         stdout, stderr = process.communicate(input)
         retcode = process.poll()
         LOG.debug("Script {0} execution finished "