bubble up errors from subprocesses

slapos/pubsub/notifier.py

@@ -40,13 +40,16 @@ def main():
     command.stdin.flush()
     command.stdin.close()
 
-    if command.wait() != 0:
+    command_failed = (command.wait() != 0)
+    command_stderr = command.stderr.read()
+
+    if command_failed:
       content = ("<p>Failed with returncode <em>%d</em>.</p>"
                  "<p>Standard error output is :</p><pre>%s</pre>") % (
         command.poll(),
-        command.stderr.read().replace('&', '&amp;')\
-                             .replace('<', '&lt;')\
-                             .replace('>', '&gt;'),
+        command_stderr.replace('&', '&amp;')\
+                      .replace('<', '&lt;')\
+                      .replace('>', '&gt;'),
       )
     else:
       content = "<p>Everything went well.</p>"
@@ -60,10 +63,14 @@ def main():
       'slapos:%s' % uuid.uuid4(),
     ])
 
+  if command_failed:
+    sys.stderr.write('%s\n' % command_stderr)
+    sys.exit(1)
+
   feed = urllib2.urlopen(args.feed_url[0])
   body = feed.read()
 
-  failed = False
+  some_notification_failed = False
   for notif_url in args.notification_url:
     notification_url = urlparse.urlparse(notif_url)
     notification_port = notification_url.port
@@ -72,16 +79,16 @@ def main():
 
     headers = {'Content-Type': feed.info().getheader('Content-Type')}
     notification = httplib.HTTPConnection(notification_url.hostname,
-                                                 notification_port)
+                                          notification_port)
     notification.request('POST', notification_url.path, body, headers)
     response = notification.getresponse()
 
     if not (200 <= response.status < 300):
       sys.stderr.write("The remote server at %s didn't send a successful reponse.\n" % notif_url)
       sys.stderr.write("Its response was %r\n" % response.reason)
-      failed = True
+      some_notification_failed = True
 
-  if failed:
+  if some_notification_failed:
     sys.exit(1)
 
 if __name__ == '__main__':