doc: add deprecation warning for netNamespaceFilePath

Add a deprecation warning when netNamespaceFilePath is configured in the
CSI configuration. This warns users that the feature will be removed in
a future version and they should migrate to using host networking for
CSI plugin pods.

The warning is logged at the WARNING level when the feature is detected
during volume staging/publishing operations.

Assisted-by: AskBob <askbob@ibm.com>
Signed-off-by: Niels de Vos <ndevos@ibm.com>

Author: nixpanic

PendingReleaseNotes.md

@@ -5,3 +5,10 @@
 ## Features
 
 ## NOTE
+
+## Deprecations
+
+- The `netNamespaceFilePath` configuration option is now deprecated and will be
+  removed in a future release. Users should migrate to using host networking for
+  CSI plugin pods instead. When this feature is detected, a deprecation warning
+  will be logged at the WARNING level.

internal/cephfs/nodeserver.go

@@ -252,6 +252,9 @@ func (ns *cephfsNodeServer) NodeStageVolume(
 		if err != nil {
 			return nil, status.Error(codes.Internal, err.Error())
 		}
+		if volOptions.NetNamespaceFilePath != "" {
+			log.WarningLog(ctx, "netNamespaceFilePath is deprecated and will be removed in a future version. Please migrate to using host networking for CSI plugin pods.")
+		}
 	}
 
 	if volOptions.BackingSnapshot {

internal/nfs/nodeserver/nodeserver.go

@@ -110,6 +110,9 @@ func (ns *nfsNodeServer) NodePublishVolume(
 		if err != nil {
 			return nil, status.Error(codes.Internal, err.Error())
 		}
+		if netNamespaceFilePath != "" {
+			log.WarningLog(ctx, "netNamespaceFilePath is deprecated and will be removed in a future version. Please migrate to using host networking for CSI plugin pods.")
+		}
 	}
 
 	err = ns.mountNFS(ctx,

internal/rbd/nodeserver.go

@@ -392,6 +392,9 @@ func (ns *NodeServer) NodeStageVolume(
 	if err != nil {
 		return nil, status.Error(codes.Internal, err.Error())
 	}
+	if rv.NetNamespaceFilePath != "" {
+		log.WarningLog(ctx, "netNamespaceFilePath is deprecated and will be removed in a future version. Please migrate to using host networking for CSI plugin pods.")
+	}
 	if isHealer {
 		err = healerStageTransaction(ctx, cr, rv, stagingParentPath)
 		if err != nil {