In many cases, you will want to manage your own systemd service definitions. Here's how.

example_systemd_unit:
  file.managed:
    - name: /etc/systemd/system/example.service
    - source: salt://example/systemd_unit.jinja
    - template: jinja
  module.run:
    - name: service.systemctl_reload
    - onchanges:
      - file: example_systemd_unit

example_running:
  service.running:
    - name: example
    - watch:
      - module: example_systemd_unit

Let's walk through what this does. First we manage the systemd unit, which is just a file ending with .service in the correct directory. You may need to change the path to example.service based on your Linux distribution.

Second we have a module.run state calling service.systemctl_reload, but only when the service file changes. Systemd documentation will tell you that you need to run systemctl reload to apply changes made to service files, this is simply the Salt way of doing that.

Finally, we have a regular service.running. You just need to make sure the name of the service matches the name of your .service file, and also make sure that the every time the service definition changes and service.systemctl_reload gets called, the service also gets restarted. A watch is an implicit require, so we don't need to specify that the service state requires the service file to be present.