I'm trying to format the local ssd that GKE node pools provide using btrfs. The drive comes preformatted with ext4. Is there a way to prevent this so that I can format it using btrfs?

I would prefer not to forcibly unmount the drive or modify the Node in GKE, but haven't been able to find a canonical way of doing this. The answer might be to run my own kubernetes cluster, but would prefer not to do this.

I use terraform to create the cluster and ansible to perform the actual modification of the underlying host:

---
- hosts: localhost
  connection: local
  become: yes
  tasks:
    - name: Update the apt package index
      apt:
        name: "*"
        state: latest
        update_cache: yes
        force_apt_get: yes

    - name: Install btrfs partition tools
      apt:
        name:
          - parted
          - btrfs-progs
        state: latest

    - name: Enable btrfs
      community.general.modprobe:
        name: btrfs
        state: present

    - name: Unmount existing partition
      ansible.posix.mount:
        path: /mnt/stateful_partition/kube-ephemeral-ssd
        state: unmounted

    - name: Delete existing ext4 partition
      parted:
        device: /dev/nvme0n1
        # number: 1
        state: absent

    - name: create partition
      parted:
        device: /dev/nvme0
        number: 1
        flags: [ lvm ]
        state: present

    - name: Create Volume Group
      community.general.lvg:
        vg: replays
        pvs: /dev/nvme0n1