Ansible Playbook for Resetting K3s

reset-etcd.yaml

- hosts: k3s-etcd # Alias for etcd hosts, defined in ansible inventory.
  tasks:
    - name: "stop etcd"
      remote_user: root
      shell: "systemctl stop etcd || true"

    - name: "rm -rf /var/lib/etcd/"
      remote_user: root
      shell: "rm -rf /var/lib/etcd/ || true"

    - name: Reboot host and wait for it to restart
      remote_user: root
      reboot:
        msg: "Reboot initiated by Ansible"
        connect_timeout: 5
        reboot_timeout: 600
        pre_reboot_delay: 0
        post_reboot_delay: 90
        test_command: whoami
        reboot_command: systemctl reboot -i
        search_paths: [ "/run/current-system/sw/bin/" ]

reset-k3s.yaml

- hosts: k3s-dev # It's an alias for host names, k3s-dev is defined in the ansible inventory.
  tasks:
    # Disable `services.k3s.enable` in your NixOS configuration.
    # On my case, I've **monkey patched** using import this way:
    # services.k3s.enable = import ./k3s-enable;
    # Adapt this as needed.
    - name: disable k3s config
      remote_user: root
      shell: echo "false" > /etc/nixos/mynixos/profiles/sbc/shared/k3s/k3s-enable

    - name: "mynixos: nixos-rebuild switch --no-write-lock-file"
      remote_user: root
      shell: "cd /etc/nixos/mynixos/; nixos-rebuild switch --no-write-lock-file"
    
    - name: stop k3s
      remote_user: root
      shell: "systemctl stop k3s || true"

    - name: umount kubelet
      remote_user: root
      shell: "KUBELET_PATH=$(mount | grep kubelet | cut -d' ' -f3); \
        ${KUBELET_PATH:+umount $KUBELET_PATH}; sleep 1"

    - name: Delete k3s data
      remote_user: root
      shell: "rm -rf /etc/rancher/{k3s,node}; \
        rm -rf /var/lib/{rancher/k3s,kubelet,longhorn,etcd,cni}"

    # Cleaning up logs is important. But I find `journalctl` terrible.
    # I don't know how to delete logs for a single unit. So I had to globally erase logs.
    # Which I did as:
    - name: clean-up logs
      remote_user: root
      shell: "journalctl --rotate --vacuum-time=1s"

    - name: Reboot host and wait for it to restart
      remote_user: root
      reboot:
        msg: Reboot initiated by Ansible
        connect_timeout: 5
        reboot_timeout: 600
        pre_reboot_delay: 0
        post_reboot_delay: 90
        test_command: whoami
        reboot_command: systemctl reboot -i
        search_paths: [ "/run/current-system/sw/bin/" ]

    # Adapt this monkey patch to your situation.
    - name: restore k3s config
      remote_user: root
      shell: echo true > /etc/nixos/mynixos/profiles/sbc/shared/k3s/k3s-enable