systemd Service Notification
This is a pure Python implementation of the
systemd
sd_notify
protocol. This protocol can be used to inform systemd about service start-up
completion, watchdog events, and other service status changes. Thus, this
package can be used to write system services in Python that play nicely with
systemd. sdnotify is compatible with both Python 2 and Python 3.
Normally the SystemdNotifier.notify method silently ignores exceptions (for example, if the
systemd notification socket is not available) to allow applications to
function on non-systemd based systems. However, setting debug=True will
cause this method to raise any exceptions generated to the caller, to
aid in debugging.
Installation
pip install sdnotify
Example Usage
This is an example of a simple Python service that informs systemd when its
startup sequence is complete. It also sends periodic status updates to systemd,
which can be viewed with systemctl status test.
test.py
import sdnotify
import time
print("Test starting up...")
# In a real service, this is where you'd do real startup tasks
# like opening listening sockets, connecting to a database, etc...
time.sleep(10)
print("Test startup finished")
# Inform systemd that we've finished our startup sequence...
n = sdnotify.SystemdNotifier()
n.notify("READY=1")
count = 1
while True:
print("Running... {}".format(count))
n.notify("STATUS=Count is {}".format(count))
count += 1
time.sleep(2)test.service
[Unit]
Description=A test service written in Python
[Service]
# Note: setting PYTHONUNBUFFERED is necessary to see the output of this service in the journal
# See https://docs.python.org/2/using/cmdline.html#envvar-PYTHONUNBUFFERED
Environment=PYTHONUNBUFFERED=true
# Adjust this line to the correct path to test.py
ExecStart=/usr/bin/python /path/to/test.py
# Note that we use Type=notify here since test.py will send "READY=1"
# when it's finished starting up
Type=notify