Revert previous commit (restore sigchld_handler)

governor.py

@@ -17,6 +17,17 @@ def sigterm_handler(signo, stack_frame):
     sys.exit()
 
 
+# handle SIGCHILD, since we are the equivalent of the INIT process
+def sigchld_handler(signo, stack_frame):
+    try:
+        while True:
+            ret = os.waitpid(-1, os.WNOHANG)
+            if ret == (0, 0):
+                break
+    except OSError:
+        pass
+
+
 class Governor:
 
     def __init__(self, config):
@@ -66,8 +77,8 @@ class Governor:
 
 def main():
     logging.basicConfig(format='%(asctime)s %(levelname)s: %(message)s', level=logging.INFO)
-    signal.signal(signal.SIGCHLD, signal.SIG_IGN)
     signal.signal(signal.SIGTERM, sigterm_handler)
+    signal.signal(signal.SIGCHLD, sigchld_handler)
 
     if len(sys.argv) < 2 or not os.path.isfile(sys.argv[1]):
         print('Usage: {} config.yml'.format(sys.argv[0]))

tests/test_governor.py

@@ -1,3 +1,4 @@
+import os
 import psycopg2
 import requests
 import subprocess
@@ -6,7 +7,7 @@ import time
 import unittest
 import yaml
 
-from governor import Governor, main, sigterm_handler
+from governor import Governor, main, sigchld_handler, sigterm_handler
 from test_ha import true, false
 from test_postgresql import Postgresql, subprocess_call, psycopg2_connect
 from test_etcd import requests_get, requests_put, requests_delete
@@ -21,6 +22,10 @@ def nop(*args, **kwargs):
     pass
 
 
+def os_waitpid(a, b):
+    return (0, 0)
+
+
 def time_sleep(_):
     raise Exception()
 
@@ -83,3 +88,8 @@ class TestGovernor(unittest.TestCase):
             time.sleep = time_sleep
             g.postgresql.sync_from_leader = false
             self.assertRaises(Exception, g.initialize)
+
+    def test_sigchld_handler(self):
+        sigchld_handler(None, None)
+        os.waitpid = os_waitpid
+        sigchld_handler(None, None)