# Copyright 2012-2014 Red Hat, Inc.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

"""
Helper module for systemd service readiness notification.
"""

import logging
import os
import socket
import sys


LOG = logging.getLogger(__name__)


def _abstractify(socket_name):
    if socket_name.startswith('@'):
        # abstract namespace socket
        socket_name = '\0%s' % socket_name[1:]
    return socket_name


def _sd_notify(unset_env, msg):
    notify_socket = os.getenv('NOTIFY_SOCKET')
    if notify_socket:
        sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
        try:
            sock.connect(_abstractify(notify_socket))
            sock.sendall(msg)
            if unset_env:
                del os.environ['NOTIFY_SOCKET']
        except EnvironmentError:
            LOG.debug("Systemd notification failed", exc_info=True)
        finally:
            sock.close()


def notify():
    """Send notification to Systemd that service is ready.

    For details see
    http://www.freedesktop.org/software/systemd/man/sd_notify.html
    """
    _sd_notify(False, 'READY=1')


def notify_once():
    """Send notification once to Systemd that service is ready.

    Systemd sets NOTIFY_SOCKET environment variable with the name of the
    socket listening for notifications from services.
    This method removes the NOTIFY_SOCKET environment variable to ensure
    notification is sent only once.
    """
    _sd_notify(True, 'READY=1')


def onready(notify_socket, timeout):
    """Wait for systemd style notification on the socket.

    :param notify_socket: local socket address
    :type notify_socket:  string
    :param timeout:       socket timeout
    :type timeout:        float
    :returns:             0 service ready
                          1 service not ready
                          2 timeout occurred
    """
    sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
    sock.settimeout(timeout)
    sock.bind(_abstractify(notify_socket))
    try:
        msg = sock.recv(512)
    except socket.timeout:
        return 2
    finally:
        sock.close()
    if 'READY=1' in msg:
        return 0
    else:
        return 1


if __name__ == '__main__':
    # simple CLI for testing
    if len(sys.argv) == 1:
        notify()
    elif len(sys.argv) >= 2:
        timeout = float(sys.argv[1])
        notify_socket = os.getenv('NOTIFY_SOCKET')
        if notify_socket:
            retval = onready(notify_socket, timeout)
            sys.exit(retval)

@@ -671,16 +671,34 @@
 n.%0A%22%22%22%0A%0A
+import contextlib%0A
 import l
@@ -1113,24 +1113,67 @@
 SOCK_DGRAM)%0A
+        with contextlib.closing(sock):%0A    
         try:
@@ -1165,32 +1165,36 @@
            try:%0A
+    
             sock
@@ -1239,24 +1239,28 @@
             
+    
 sock.sendall
@@ -1265,16 +1265,20 @@
 ll(msg)%0A
+    
         
@@ -1311,16 +1311,20 @@
         
+    
 del os.e
@@ -1351,24 +1351,28 @@
 T'%5D%0A        
+   
+ 
 except Envir
@@ -1384,16 +1384,20 @@
 tError:%0A
+    
         
@@ -1460,50 +1460,8 @@
 ue)%0A
-        finally:%0A            sock.close()%0A
 %0A%0Ade
@@ -2542,24 +2542,63 @@
 fy_socket))%0A
+    with contextlib.closing(sock):%0A    
     try:%0A   
@@ -2586,32 +2586,36 @@
 ):%0A        try:%0A
+    
         msg = so
@@ -2627,16 +2627,20 @@
 cv(512)%0A
+    
     exce
@@ -2662,24 +2662,28 @@
 ut:%0A        
+    
 return 2%0A   
@@ -2687,38 +2687,8 @@
     
-finally:%0A        sock.close()%0A
     
@@ -2712,24 +2712,28 @@
 sg:%0A        
+ 
+   
 return 0%0A   
@@ -2737,14 +2737,22 @@
     
+   
+ 
 else:%0A
+    
     

Use contextlib.closing instead of try ... finally: sock.close