use diplonat autodiscovery to set ip addr

cluster/prod/app/jitsi/deploy/jitsi.hcl

@@ -222,11 +222,14 @@ EOF
         ]
       }
 
-      env {
-        # Our container can autodetect the public IP with the ifconfig.me service
-        # However we would like to avoid relying on a 3rd party service for production use
-        # That's why I am setting the public IP address statically here VVVV
-        JITSI_NAT_PUBLIC_IP = "${meta.public_ipv4}"
+      template {
+         data = <<EOH
+	 {{ with $a := env "attr.unique.hostname" | printf "diplonat/autodiscovery/ipv4/%s" | key | parseJSON }}
+         JITSI_NAT_PUBLIC_IP = {{ $a.address }}
+	 {{ end }}
+	 EOH
+	 destination = "secrets/jitsi-videobridge.env"
+	 env         = true
       }
 
       template {