Download and unzip package from following URL

https://github.com/Dreamacro/clash

Execute the clash once and it generated the .config folder under /home/<user> path

Automactically download initial config.yaml & country.mmdb from web.

Download the config.yaml from the ladder site and replace the original config file.

Create clash.service file as following

# edit and save this file to /usr/lib/systemd/system/clash.service
[Unit]
Description=clash
After=network.target
[Service]
WorkingDirectory=/home/<usrid>/.config/clash
ExecStart= /home/<usrid>/.config/clash/start-clash.sh
ExecStop= /home/<usrid>/.config/clash/stop-clash.sh
Environment="HOME=/home/<usrid>"
#Environment="CLASH_URL="
[Install]
WantedBy=multi-user.target

Create two shell scripts:

#!/bin/bash
# save this file to ${HOME}/.config/clash/start-clash.sh
# save pid file
echo $$ > ${HOME}/.config/clash/clash.pid
${HOME}/work/clash

#!/bin/bash
# save this file to ${HOME}/.config/clash/stop-clash.sh
# read pid file
PID=`cat ${HOME}/.config/clash/clash.pid`
kill -9 ${PID}
rm ${HOME}/.config/clash/clash.pid

Then enable and start clash as service

systemctl enable clash
systemctl start clash