fix: ensure that Kong service is stopped before Envoy service is started

Per https://www.freedesktop.org/software/systemd/man/latest/systemd.unit.html#Before=, "Given two units with any ordering dependency between them, if one unit is shut down and the other is started up, the shutdown is ordered before the start-up. It doesn't matter if the ordering dependency is After= or Before=, in this case. It also doesn't matter which of the two is shut down, as long as one is shut down and the other is started up; the shutdown is ordered before the start-up in all cases. If two units have no ordering dependencies between them, they are shut down or started up simultaneously, and no ordering takes place."

Also ensures that Envoy will take priority over Kong on reboot if both are enabled.

Author: thebengeu

ansible/files/kong_config/kong.service.j2

@@ -4,6 +4,9 @@ After=postgrest.service gotrue.service adminapi.service
 Wants=postgrest.service gotrue.service adminapi.service
 Conflicts=envoy.service
 
+# Ensures that Kong service is stopped before Envoy service is started
+Before=envoy.service
+
 [Service]
 Type=forking
 ExecStart=/usr/local/bin/kong start -c /etc/kong/kong.conf