Difference between revisions of "Systemd service file"
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m (→Need to know commands) |
m (→My service) |
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| Line 3: | Line 3: | ||
<source lang=bash> | <source lang=bash> | ||
#!/bin/bash | #!/bin/bash | ||
| − | # | + | |
| − | + | ||
| − | + | # Example: Bash catches(trap) exit signal and runs cleanup function | |
| + | trap 'cleanup' EXIT | ||
| + | cleanup() { | ||
| + | echo "$(date): Cleaning up" | tee -a $LOGFILE | ||
| + | } | ||
| + | |||
| + | |||
IP="192.168.1.72" | IP="192.168.1.72" | ||
LOGFILE="/tmp/myserver.log" | LOGFILE="/tmp/myserver.log" | ||
| + | |||
| + | echo "$(date): Starting service" | tee -a $LOGFILE | ||
while : | while : | ||
| Line 13: | Line 21: | ||
if ping -c 1 $IP > /dev/null 2>&1 | if ping -c 1 $IP > /dev/null 2>&1 | ||
then | then | ||
| − | echo "$(date) online" >> $LOGFILE | + | echo "$(date): online" >> $LOGFILE |
else | else | ||
| − | echo "$(date) OFFLINE" >> $LOGFILE | + | echo "$(date): OFFLINE" >> $LOGFILE |
fi | fi | ||
sleep 60 | sleep 60 | ||
done | done | ||
| + | |||
</source> | </source> | ||
| + | |||
==My service-file== | ==My service-file== | ||
<source lang=bash> | <source lang=bash> | ||
Revision as of 10:20, 17 April 2024
If i want a service daemon to log if my server is online every minute. The following procedure could be used:
Contents
My service
#!/bin/bash
# Example: Bash catches(trap) exit signal and runs cleanup function
trap 'cleanup' EXIT
cleanup() {
echo "$(date): Cleaning up" | tee -a $LOGFILE
}
IP="192.168.1.72"
LOGFILE="/tmp/myserver.log"
echo "$(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