defaultMode and fsGroup not working together

[Masber]

Dear rke2 community,

My environment:

Client Version: version.Info{Major:“1”, Minor:“22”, GitVersion:“v1.22.1”, GitCommit:“632ed300f2c34f6d6d15ca4cef3d3c7073412212”, GitTreeState:“clean”, BuildDate:“2021-08-19T15:45:37Z”, GoVersion:“go1.16.7”, Compiler:“gc”, Platform:“linux/amd64”}
Server Version: version.Info{Major:“1”, Minor:“29”, GitVersion:“v1.29.0+rke2r1”, GitCommit:“3f7a50f38688eb332e2a1b013678c6435d539ae6”, GitTreeState:“clean”, BuildDate:“2023-12-13T22:06:58Z”, GoVersion:“go1.21.5 X:boringcrypto”, Compiler:“gc”, Platform:“linux/amd64”}

I need to mount a configmap as a volume into my containers and also change user owner top 1000 and file permissions to 0600. I tried doing this by using defaultMode to set the file permissions and fsGroup to set the owner:

        volume:
          name: "my-config-volume"

          config_map:
            name: "my-map"
            defaultMode: "0600"

and

        securityContext:
          fsGroup: "1000"

But this is not working because the file permissions is not changed. However, defaultMode do work if fsGroup is missing. Could this be related? kubernetes/kubernetes#57935

Any idea how could I change the owner of a file and also the file permissions of a configmap mounted as a volume?

Thank you very much