From 1d81becdefabf6bf67c3f78e3129b82c64932a1d Mon Sep 17 00:00:00 2001
From: Alexander Richards <a.richards@imperial.ac.uk>
Date: Mon, 9 Dec 2019 10:49:13 +0000
Subject: [PATCH] Update daemon PID before parent exits

This commit will have the parent process write the daemon PID before it exits. This ensures that immediately after parent exits a valid PID is available from the pid file.
---
 daemonize.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/daemonize.py b/daemonize.py
index 2585b09..d17b9a5 100644
--- a/daemonize.py
+++ b/daemonize.py
@@ -106,6 +106,8 @@ def start(self):
                 self.logger.error("Unable to fork, errno: {0}".format(e.errno))
                 sys.exit(1)
             if process_id != 0:
+                with open(self.pid, "w") as pidfile:
+                    pidfile.write(str(process_id))
                 if self.keep_fds:
                     # This is the parent process. Exit without cleanup,
                     # see https://github.com/thesharp/daemonize/issues/46