To use systemd socket activation feature for zero downtime upgrade follow this guide:

1. copy the service definition unit file gwentapi.service and the socket definition unit file gwentapi.socket to /etc/systemd/system/.

2. Copy the executable and the config file at the location defined by the service unit file: /usr/local/bin/ by default.

3. Rename the executable to gwentapi to match the filename in the service unit file.

4. Enable the socket and start it

   1. systemctl enable gwentapi.socket
   2. systemctl start gwentapi.socket

This experimental feature is only supported on Linux with systemd.

1. Replace the executable
2. Restart the service with systemctl