diff --git a/apps/workadventure/README.md b/apps/workadventure/README.md
index 6ea8ae5..dde9c01 100644
--- a/apps/workadventure/README.md
+++ b/apps/workadventure/README.md
@@ -60,3 +60,9 @@ sudo: policy plugin failed session initialization
 
 
 ### v3: all components work
+
+* Production docker-compose:
+  https://github.com/thecodingmachine/workadventure/blob/master/contrib/docker/docker-compose.prod.yaml
+
+
+### v4: helm re-usable
diff --git a/generic/service-no-port.yaml b/generic/service-no-port.yaml
new file mode 100644
index 0000000..164518c
--- /dev/null
+++ b/generic/service-no-port.yaml
@@ -0,0 +1,11 @@
+# Cannot use arbitrary ports:
+# [13:18] nb3:generic% kubectl apply -f service-no-port.yaml
+# The Service "my-service" is invalid: spec.ports: Required value
+
+apiVersion: v1
+kind: Service
+metadata:
+  name: my-service
+spec:
+  selector:
+    app: myapp