systemd jobs

1. Create a new .service file named "mylogger.service" located in /etc/systemd/system directory, hint: you can copy sshd.service from /usr/lib/systemd/system if you want.

 [root@linuxacademy]# cd /etc/systemd/system; cp /usr/lib/systemd/system/sshd.service mylogger.service

2. Make sure the script executes only AFTER the sshd.service, service has been started.

[Unit]
Description=My logger service
After=sshd.service

3. In the [Service] section you can remove all settings except for ExecStart. 

[Service]
ExecStart

4. Using the ExecStart option make it so that whenever the script is started it adds the following line "logger -f /var/log/messages "Hello world!".

ExecStart=/usr/bin/logger -f /var/log/messages "Hello world! $(date)"

5. In the [Install] section make it so that the WantedBy option starts the service, if the service is enabled, when the system enters the multi-user.target, once completed, save and exit.

[Install]

WantedBy=multi-user.target

[Unit]
Description=OpenSSH server daemon
After=sshd.service

[Service]
ExecStart=/usr/bin/logger -f /var/log/messages "Hello world! $(date)"

[Install]
WantedBy=multi-user.target

6. Using systemctl enable the service.

[root@linuxacademy]# systemctl enable mylogger

7. Using systemctl start the service.

[root@linuxacademy]# systemctl start mylogger

8. View the status of the mylogger service.

[root@linuxacademy]# systemctl status mylogger

9. Using tail verify that the logger service sent a message to the /var/log/messages log file.

[root@linuxacademy]# tail -f /var/log/messages

10. Reboot your system.

[root@linuxacademy]# reboot

11. Log back into the system and verify the service is running and also has added another line to the /var/log/messages log file.

[root@linuxacademy]# tail -f /var/log/messages

12. Send a global message to the system stating "It worked!"

[root@linuxacademy]# wall "It worked!"