How to write a systemd service
https://zh.opensuse.org/openSUSE:How_to_write_a_systemd_service
Linux 服务管理两种方式service和systemctl
https://www.cnblogs.com/shijingjing07/p/9301590.html
systemd.service — Service unit configuration
https://www.freedesktop.org/software/systemd/man/systemd.service.html
systemd service file environment variables
Using environment variables in systemd units
https://coreos.com/os/docs/latest/using-environment-variables-in-systemd-units.html
https://serverfault.com/questions/413397/how-to-set-environment-variable-in-systemd-service
Getting started with systemd
https://coreos.com/os/docs/latest/getting-started-with-systemd.html
Systemd: why isn't it possible to use %i in the first argument of ExecStart=?
https://serverfault.com/questions/666269/systemd-why-isnt-it-possible-to-use-i-in-the-first-argument-of-execstart
How to use a parameter in ExecStart command line?
https://stackoverflow.com/questions/21502264/how-to-use-a-parameter-in-execstart-command-line
For details about the %I and %i substitutions, see the Specifiers section of man 5 systemd.unit or systemd.unit
有关％I和％i替换的详细信息，请参阅man 5 systemd.unit或systemd.unit的说明符部分。
https://www.freedesktop.org/software/systemd/man/systemd.unit.html#Specifiers
systemd - Giving my service multiple arguments
https://superuser.com/questions/728951/systemd-giving-my-service-multiple-arguments
https://wiki.archlinux.org/index.php/Systemd
