General Information

Creating a systemd until file (service script).

Checklist

• Enterprise Linux 7

• /usr/lib/systemd/system ⇒ system unit configuration files (default with system)
• /etc/systemd/system ⇒ additional configuration files (downloaded or custom)

• Download the code
• Modify each section to make sense for your service
• Copy to /etc/systemd/system/<name-of-service>.service
• Start your service

  systemctl start <name-of-service>
   
  ----
   
  ====== The Service Unit File ======
   
  <code bash myprog.service>
  [Unit]
  Description=My Awesome Program
  After=syslog.target
   
  [Service]
  EnvironmentFile=/etc/myprog.d/config
  ExecStart=/usr/local/bin/myprog.sh
  Restart=on-abort
   
  [Install]
  WantedBy=multi-user.target

• Description ⇒ Displays near the top of output on “systemctl status myprog.service”
• After ⇒ can be any valid “.target” unit
  • See all: systemctl -t target –all
• EnvironmentFile ⇒ Configuration file to load
• ExecStart ⇒ Executable to start
• Restart ⇒ Auto restarts the program if an un-handled exit error occurs
• WantedBy ⇒ If enabled, start under which target

This is the script that was used to test the custom systemd service unit file.

/usr/local/bin/myprog.sh

#!/bin/bash
 
echo "Welcome to my program"
logger -p info "$0 has started on $(date)"
 
while true; do
  logger -p info "$0 is still running..."
  sleep 30
done