Merge pull request #1339 from codeswhite/patch-systemctl-restart-check

Check if a service is running (Fixed #1337)

testUpdateHostsFile.py

@@ -1324,7 +1324,7 @@ class TestFlushDnsCache(BaseStdout):
                 self.assertIn(expected, output)
 
     @mock.patch("os.path.isfile", side_effect=[True, False, False, True] + [False] * 10)
-    @mock.patch("subprocess.call", side_effect=[1, 0])
+    @mock.patch("subprocess.call", side_effect=[1, 0, 0])
     def test_flush_posix_fail_then_succeed(self, *_):
         with self.mock_property("platform.system") as obj:
             obj.return_value = "Linux"

updateHostsFile.py

@@ -1306,6 +1306,9 @@ def flush_dns_cache():
                 )
 
                 if os.path.isfile(service_file):
+                    if 0 != subprocess.call([systemctl, "status", service],
+                                            stdout=subprocess.DEVNULL):
+                        continue
                     dns_cache_found = True
 
                     if subprocess.call(SUDO + [systemctl, "restart", service]):