Overview

You need the process start automatically when your develop the embedded system like robot, settop box, digital TV ... In that case, you can use systemd daemon. In this page, It introduces how to make systemd daemon & install it in the system.

example

make your *.service file

make the *.service file example) your_daemon.service

[Unit]                                                                                                      
Description=your daemon service                                                                               
                                                                                                            
[Service]                                                                                                   
PermissionsStartOnly=yes                                                                                    
User=ubuntu                                                                                                    
Group=ubuntu                                                                                             
Type=simple                                                                                                 
Environment="YOUR_ENV_VALUE_A=11"                                                                              
Environment="YOUR_ENV_VALUE_B=blabla"                                                                             
Environment="YOUR_ENV_VALUE_C=/home/ubuntu/your_bin"                                                                             
Environment="XDG_RUNTIME_DIR=/run/user/1000"                                                                
WorkingDirectory=/home/ubuntu/workspace/path_to_your_script         
ExecStart=/home/ubuntu/workspace/path_to_your_script/bringup_your_service.sh
ExecStop=/home/ubuntu/workspace/path_to_your_script/cleanup_your_service.sh
                                                                                                            
[Install]                                                                                                   
WantedBy=multi-user.target                                                                                  

make your bringup script

example) bringup_your_service.sh

it is placed on '/home/ubuntu/workspace/path_to_your_script/bringup_your_service.sh'

bringup_your_service.sh

#!/bin/bash
# start the process A with non blocking (&)
/home/ubuntu/workspace/path_to_your_script/Process_A &
# start the process B with non blocking (&)
/home/ubuntu/workspace/path_to_your_script/Process_B &

# And keep running
while :                                    
do                                         
  echo -e ${ROBOT_NAME}" daemon is running"
  sleep 5                                  
done                                       

make your cleanup script

example) cleanup_your_service.sh

it is placed on '/home/ubuntu/workspace/path_to_your_script/cleanup_your_service.sh'

cleanup_your_service.sh

#!/bin/bash

# kill the processes that bringup script made 
pkill -9 Process_A
pkill -9 Process_B

Install your service script

example)

$ sudo cp your_daemon.service /etc/systemd/system
$ sudo systemctl enable your_daemon.service
$ sudo systemctl daemon-reload

Now your service will be run automatically when the system reboot. You can start or stop your service

$ sudo systemctl stop your_daemon.service
$ sudo systemctl start your_daemon.service

Uninstall your service script

example)

$ sudo systemctl stop your_daemon.service
$ sudo systemctl disable your_daemon.service
$ sudo rm /etc/systemd/system/your_daemon.service
$ sudo systemctl daemon-reload
$ sudo systemctl reset-failed