chore(env): PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING_STATUS_FILE

- With retro-compatibility with `PORT_FORWARDING_STATUS_FILE`

Dockerfile

@@ -102,7 +102,7 @@ ENV VPN_SERVICE_PROVIDER=pia \
     # # Private Internet Access only:
     PRIVATE_INTERNET_ACCESS_OPENVPN_ENCRYPTION_PRESET= \
     PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING=off \
-    PORT_FORWARDING_STATUS_FILE="/tmp/gluetun/forwarded_port" \
+    PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING_STATUS_FILE="/tmp/gluetun/forwarded_port" \
     # # Cyberghost only:
     OPENVPN_CLIENTCRT_SECRETFILE=/run/secrets/openvpn_clientcrt \
     OPENVPN_CLIENTKEY_SECRETFILE=/run/secrets/openvpn_clientkey \

internal/configuration/sources/env/portforward.go

@@ -16,7 +16,12 @@ func (r *Reader) readPortForward() (
 		return portForwarding, fmt.Errorf("environment variable %s: %w", key, err)
 	}
 
-	portForwarding.Filepath = envToStringPtr("PORT_FORWARDING_STATUS_FILE")
+	_, value := r.getEnvWithRetro(
+		"PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING_STATUS_FILE",
+		"PORT_FORWARDING_STATUS_FILE")
+	if value != "" {
+		portForwarding.Filepath = stringPtr(value)
+	}
 
 	return portForwarding, nil
 }