Recommended changes from review of #1568

- Make Resources an `interface{}` to support arbitrary yaml
- Remove `wwctl resource` as incompatible with arbitrary yaml
- Revert changes to host overlay templates
- Remove NFS mount options from warewulf.conf
- Replace NFS support / resource prefix with "fstab" resource
- Move resources to profiles
- Migrate warewulf.conf mounts to nodes.conf with `wwctl upgrade`
- Add documentation

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

internal/pkg/node/methods.go

@@ -154,13 +154,16 @@ func recursiveFlatten(obj interface{}) (hasContent bool) {
 		case reflect.Map:
 			mapIter := valObj.Elem().Field(i).MapRange()
 			for mapIter.Next() {
-				if mapIter.Value().Kind() == reflect.String {
-					if mapIter.Value().String() != "" {
-						hasContent = true
+				switch mapIter.Value().Kind() {
+				case reflect.Map, reflect.Pointer, reflect.Slice:
+					if mapIter.Value().Type().Elem().Kind() == reflect.Struct {
+						ret := recursiveFlatten(mapIter.Value().Interface())
+						hasContent = ret || hasContent
+					} else {
+						hasContent = !mapIter.Value().IsZero() || hasContent
 					}
-				} else {
-					ret := recursiveFlatten(mapIter.Value().Interface())
-					hasContent = ret || hasContent
+				default:
+					hasContent = !mapIter.Value().IsZero() || hasContent
 				}
 			}