systemd-notify.md

LAB 5: systemd-notify

How systemd knows about application state? We have a sd_notify syscall that we might use. There're 2 libraries that implements via cython this syscall:

• sd_notify
• systemd.notify

So now let's have some fun with it. Enter sd-notify-python directory and follow those steps:

1. sd-notify:
   1. view sd-notify-app-service.service file
   2. copy service file to /etc/systemd/system/ and enable/run it
   3. view journalctl -f -u sd-notify-app-service
2. systemd-notify + socket activation
   1. view systemd-notify-app.service and systemd-notify-app.socket
   2. copy service and socket file to /etc/systemd/system/
   3. start systemd-notify-app.socket service
   4. curl localhost:1025 && journalctl -f

Remember about reading socket activation posts:

• http://0pointer.de/blog/projects/socket-activation.html
• http://0pointer.de/blog/projects/socket-activation2.html
• http://0pointer.de/blog/projects/socket-activated-containers.html