Update configmap overlay doc

horizon/README.md

@@ -31,7 +31,7 @@ The chart supports specifying a list of ConfigMaps with `core.overlayConfigMaps`
 
 ### Plain files
 
-Provide one or more plain files (text and/or binary) in the ConfigMap and specify the directory where these files will be copied.
+Provide one or more plain files (text and/or binary) in the ConfigMap and specify the directory where these files will be copied. Plain files does not recognize recursive directories due to ConfigMap restriction. See `Overlay ConfigMap Notes` item #2 for details.
 
 Here is a configuration example:
 
@@ -83,7 +83,7 @@ kubectl create configmap -n $instance $configmap --from-file=lots-of-zeros.zip
 ### Overlay ConfigMap Notes
 
 1. This mechanism can be used only to *add* files. When `etc` files are copied into the `onms-etc-pvc` PVC, removing a file from the ConfigMap will not cause the file in the PVC to be deleted. In this case, you will need to delete the file manually after updating the ConfigMap to remove the file. You can do this with `kubectl exec -n $instance onms-core-0 -- rm etc/testing-configmap`.
-2. ConfigMaps cannot contain recursive directory structures--only files. If you need to put files into multiple directories, each directory will need to be its own ConfigMap. `kubectl create configmap` will silently ignore subdirectories.
+2. ConfigMaps cannot contain recursive directory structures--only files. If you need to put files into multiple directories, each directory will need to be its own ConfigMap. `kubectl create configmap` will silently ignore subdirectories. A better alternative is ZIP files.
 3. ConfigMaps can't be larger than 1 MB (see the note [here](https://kubernetes.io/docs/concepts/configuration/configmap/#motivation). If you have more content, you will need to split it across multiple ConfigMaps or compressed into ZIP files.
 4. Use `kubectl delete configmap -n $instance $configmap` to delete an existing ConfigMap before updating.
 5. After updating a ConfigMap, you will need to restart the pod; for example, `kubectl rollout restart -n $instance statefulset/onms-core`