Integration of syncplay-server with systemd
===========================================
As of 1.6.8+repack1-1 syncplay-server ships
/usr/lib/systemd/system/syncplay-server.service to run syncplay-server at boot
time. By default that systemd service is deactivated.

To enable it, run as root:

  systemctl enable --now syncplay-server.service

To deactivate it, run as root:

  systemctl disable --now syncplay-server.service

If you need a different configuration, disable as above, copy
/usr/lib/systemd/system/syncplay-server.service to /etc/systemd/system, and edit
the file to fit your needs. When you are done, run as root:

  systemctl daemon-reload

and enable/disable as documented above.

TLS Encryption
==============
NOTE: It does NOT work with self-signed certificates.

Prepare and configure…
  1. a domain
  2. a valid certificate for that domain (E.g., Let's Encrypt. The Debian
     package works with certbot. Other methods will require manual integration.)

If you have both set up, then…
  1. configure your domain in /etc/default/syncplay-server
  3. run as root: systemctl restart syncplay-server.service

The systemd service file uses systemd's DynamicUser= setting to generate user,
group and /run/syncplay-server on the fly. ExecStartPre= executes the certbot
hook to make it copy the certificate files into /run/syncplay-server with secure
permissions and owned by the DynamicUser's group.

It is not necessary to reload or restart syncplay-server.service, as
syncplay-server automatically detects renewed certificates on incoming
connections. I.e., it is enough to have the certbot hook script update the
certificates in /run/syncplay-server without any further action.