A user Systemd service should be placed in ~/.config/systemd/user/ directory if you want to have full ownership as normal user. Create it if it doesn’t exist.

mkdir -p  ~/.config/systemd/user/

Create a systemd service unit file under the directory.

The @ symbol indicates that a substitution will be made. Systemd will take whatever you type after it and replace the variable %i inside the service unit file. The variable can be seen in this excerpt of the SimpleHTTPServer@.service file:

$ vim  ~/.config/systemd/user/SimpleHTTPServer@.service
[Unit]
Description=SimpleHTTPServer
After=network-online.target
Wants=network-online.target

[Service]
ExecStart=/usr/bin/python3 -m http.server %i
WorkingDirectory=%h/Public
Restart=always

[Install]
WantedBy=multi-user.target

Reload systemd.

$ systemctl --user daemon-reload

Confirm the service is available.

$ systemctl --user list-unit-files SimpleHTTPServer@.service
UNIT FILE                 STATE
SimpleHTTPServer@.service disabled

1 unit files listed.

You can start the service then after creation.

Start instance with the appropriate port. 1991 is our port to listen.
To manage, just append port after the @ symbol.

$ systemctl --user enable --now SimpleHTTPServer@1991
Created symlink /home/grizzly/.config/systemd/user/multi-user.target.wants/SimpleHTTPServer@1991.service → /home/grizzly/.config/systemd/user/SimpleHTTPServer@.service.

Let’s check the status of our service.

$ systemctl --user status SimpleHTTPServer@1991.service
● SimpleHTTPServer@1991.service - SimpleHTTPServer
   Loaded: loaded (/home/grizzly/.config/systemd/user/SimpleHTTPServer@.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2022-03-27 09:51:28 CEST; 1min 30s ago
 Main PID: 13536 (python3)
   CGroup: /user.slice/user-14200.slice/user@14200.service/SimpleHTTPServer.slice/SimpleHTTPServer@1991.service
           └─13536 /usr/bin/python3 -m http.server 1991

Mar 27 09:51:28 de1 systemd[11908]: Started SimpleHTTPServer.

That’s the same process you’ll use to create any other Systemd service that you want to manage without privilege escalation or creating a different system user to run the service.