Difference between revisions of "Systemd service file"
From Teknologisk videncenter
m (→My service) |
m (→My service) |
||
| Line 9: | Line 9: | ||
# Example: Bash catches(trap) exit signal and runs cleanup function | # Example: Bash catches(trap) exit signal and runs cleanup function | ||
| − | |||
cleanup() { | cleanup() { | ||
echo "$(date): Cleaning up" | tee -a $LOGFILE | echo "$(date): Cleaning up" | tee -a $LOGFILE | ||
} | } | ||
| + | trap 'cleanup' EXIT | ||
echo "$(date): Starting service" | tee -a $LOGFILE | echo "$(date): Starting service" | tee -a $LOGFILE | ||
Revision as of 10:32, 17 April 2024
If i want a service daemon to log if my server is online every minute. The following procedure could be used:
Contents
My service
#!/bin/bash
IP="192.168.1.72"
LOGFILE="/tmp/myserver.log"
# Example: Bash catches(trap) exit signal and runs cleanup function
cleanup() {
echo "$(date): Cleaning up" | tee -a $LOGFILE
}
trap 'cleanup' EXIT
echo "$(date): Starting service" | tee -a $LOGFILE
while :
do
if ping -c 1 $IP > /dev/null 2>&1
then
echo "$(date): online" >> $LOGFILE
else
echo "$(date): OFFLINE" >> $LOGFILE
fi
sleep 60
done
My service-file
# Filename: /lib/systemd/system/mysserver-onlined.service
# Owner: root:root
# Permissions: 644
[Unit]
Description=Test if my server is online
After=network.target
[Service]
ExecStart=/usr/local/sbin/mysserver-online.sh
Type=simple
Restart=always
[Install]
WantedBy=default.target
Enabling the service
Copy files to destination
Make sure your service and your service-file are in the right destination.
sudo cp myserver-online.sh /usr/local/sbin
sudo chown root:root /usr/local/sbin/myserver-online.sh
sudo chmod 755 /usr/local/sbin/myserver-online.sh
sudo cp myserver-onlined.service /lib/systemd/system
sudo chown root:root /lib/systemd/system/myserver-onlined.service
sudo chmod 644 /lib/systemd/system/myserver-onlined.service
Reload system file
systemd reloads and hopefully finds your new service-file
sudo systemctl daemon-reload
Verify files
systemd-analyze checks the service-file for errors. (Correct errors if any - remember to reload system files)
sudo systemd-analyze verify myserver-onlined.service
Enable service-file
Enabling the service file makes it a part of systemd If it is a service and should be running all the time - do shutdown -r now and check with systemctl status myserver-onlined that it is running
sudo systemctl enable myserver-onlined.service
Need to know commands
# Check the service status
sudo systemctl status myserver-onlined.service
# Start the service manually
sudo systemctl start myserver-onlined.service
# Stop the service manually
sudo systemctl stop myserver-onlinedservice
# Restart the service manually
sudo systemctl restart myserver-onlined.service
# If you make changes to the service file - reload
sudo systemctl daemon-reload