---
# One-time migration: zvol/XFS → ZFS dataset for /srv/kind/solana
#
# Background:
#   Biscayne used a ZFS zvol formatted as XFS to work around io_uring/ZFS
#   deadlocks. With ZFS upgraded to 2.2.9 (io_uring fix) and graceful
#   shutdown via admin RPC, the zvol/XFS layer is unnecessary overhead.
#
# What this does:
#   1. Stops docker to release all bind mounts referencing /srv/kind
#   2. Unmounts the zvol and any leftover temp mounts
#   3. Creates a ZFS dataset at biscayne/DATA/srv/kind/solana (if needed)
#   4. Destroys the zvol (no data copy — stale data, fresh snapshot on restart)
#   5. Updates fstab, mounts ramdisk, creates directories
#   6. Restarts docker (kind cluster comes back)
#
# Usage:
#   ansible-playbook -i inventory/biscayne.yml playbooks/biscayne-migrate-storage.yml
#
# After migration, rebuild the container image with biscayne-sync-tools.yml
# --tags build-container, then start the validator with biscayne-recover.yml.
#
- name: Migrate storage from zvol/XFS to ZFS dataset
  hosts: all
  gather_facts: false
  become: true
  vars:
    kind_cluster: laconic-70ce4c4b47e23b85
    zvol_device: /dev/zvol/biscayne/DATA/volumes/solana
    zvol_dataset: biscayne/DATA/volumes/solana
    new_dataset: biscayne/DATA/srv/kind/solana
    kind_solana_dir: /srv/kind/solana
    ramdisk_mount: /srv/kind/solana/ramdisk
    ramdisk_size: 1024G
    zvol_tmp_mount: /mnt/zvol-migration-tmp

  tasks:
    # ---- assess current state ---------------------------------------------------
    - name: Check if zvol device exists
      ansible.builtin.stat:
        path: "{{ zvol_device }}"
      register: zvol_exists

    - name: Check if ZFS dataset already exists
      ansible.builtin.command: zfs list -H -o name {{ new_dataset }}
      register: dataset_exists
      failed_when: false
      changed_when: false

    - name: Check current mount type at {{ kind_solana_dir }}
      ansible.builtin.shell:
        cmd: set -o pipefail && findmnt -n -o FSTYPE {{ kind_solana_dir }}
        executable: /bin/bash
      register: current_fstype
      failed_when: false
      changed_when: false

    - name: Check if temp zvol mount exists
      ansible.builtin.shell:
        cmd: set -o pipefail && findmnt -n {{ zvol_tmp_mount }}
        executable: /bin/bash
      register: tmp_mount_exists
      failed_when: false
      changed_when: false

    - name: Report current state
      ansible.builtin.debug:
        msg:
          zvol_exists: "{{ zvol_exists.stat.exists | default(false) }}"
          dataset_exists: "{{ dataset_exists.rc == 0 }}"
          current_fstype: "{{ current_fstype.stdout | default('none') }}"
          temp_mount: "{{ tmp_mount_exists.rc == 0 }}"

    - name: End play if already migrated
      ansible.builtin.meta: end_play
      when:
        - dataset_exists.rc == 0
        - current_fstype.stdout | default('') == 'zfs'
        - not (zvol_exists.stat.exists | default(false))

    # ---- stop docker to release all /srv/kind references -----------------------
    - name: Stop docker (releases kind bind mounts to /srv/kind)
      ansible.builtin.systemd:
        name: docker
        state: stopped
      register: docker_stopped
      changed_when: docker_stopped.changed

    - name: Stop docker socket
      ansible.builtin.systemd:
        name: docker.socket
        state: stopped

    # ---- unmount everything referencing the zvol --------------------------------
    - name: Unmount temp zvol mount (leftover from interrupted migration)
      ansible.posix.mount:
        path: "{{ zvol_tmp_mount }}"
        state: unmounted
      when: tmp_mount_exists.rc == 0

    - name: Remove temp mount directory
      ansible.builtin.file:
        path: "{{ zvol_tmp_mount }}"
        state: absent

    - name: Unmount ramdisk if mounted
      ansible.posix.mount:
        path: "{{ ramdisk_mount }}"
        state: unmounted
      failed_when: false

    - name: Unmount zvol from {{ kind_solana_dir }}
      ansible.posix.mount:
        path: "{{ kind_solana_dir }}"
        state: unmounted
      when: current_fstype.stdout | default('') == 'xfs'

    # ---- create ZFS dataset if needed ------------------------------------------
    - name: Create ZFS dataset {{ new_dataset }}
      ansible.builtin.command: >
        zfs create -o mountpoint={{ kind_solana_dir }} {{ new_dataset }}
      changed_when: true
      when: dataset_exists.rc != 0

    - name: Mount ZFS dataset if it already existed but isn't mounted
      ansible.builtin.command: zfs mount {{ new_dataset }}
      changed_when: true
      failed_when: false
      when: dataset_exists.rc == 0

    - name: Verify ZFS dataset is mounted
      ansible.builtin.shell:
        cmd: set -o pipefail && findmnt -n -o FSTYPE {{ kind_solana_dir }} | grep -q zfs
        executable: /bin/bash
      changed_when: false

    # ---- destroy zvol -----------------------------------------------------------
    - name: Destroy zvol {{ zvol_dataset }}
      ansible.builtin.command: zfs destroy -r {{ zvol_dataset }}
      changed_when: true
      when: zvol_exists.stat.exists | default(false)

    # ---- create directory structure on new dataset ------------------------------
    - name: Create solana data directories
      ansible.builtin.file:
        path: "{{ kind_solana_dir }}/{{ item }}"
        state: directory
        mode: "0755"
      loop:
        - ledger
        - snapshots
        - log
        - ramdisk

    # ---- update fstab -----------------------------------------------------------
    - name: Remove zvol fstab entry
      ansible.builtin.lineinfile:
        path: /etc/fstab
        regexp: '^\S+zvol\S+\s+{{ kind_solana_dir }}\s'
        state: absent

    - name: Remove any XFS fstab entry for {{ kind_solana_dir }}
      ansible.builtin.lineinfile:
        path: /etc/fstab
        regexp: '^\S+\s+{{ kind_solana_dir }}\s+xfs'
        state: absent

    - name: Update tmpfs ramdisk fstab entry
      ansible.builtin.lineinfile:
        path: /etc/fstab
        regexp: '^\S+\s+{{ ramdisk_mount }}\s'
        line: "tmpfs {{ ramdisk_mount }} tmpfs nodev,nosuid,noexec,nodiratime,size={{ ramdisk_size }},nofail,x-systemd.requires=zfs-mount.service 0 0"

    - name: Reload systemd
      ansible.builtin.systemd:
        daemon_reload: true

    # ---- mount ramdisk ----------------------------------------------------------
    - name: Mount tmpfs ramdisk
      ansible.posix.mount:
        path: "{{ ramdisk_mount }}"
        src: tmpfs
        fstype: tmpfs
        opts: "nodev,nosuid,noexec,nodiratime,size={{ ramdisk_size }}"
        state: mounted

    - name: Ensure accounts directory on ramdisk
      ansible.builtin.file:
        path: "{{ ramdisk_mount }}/accounts"
        state: directory
        mode: "0755"

    # ---- restart docker (brings kind back) -------------------------------------
    - name: Start docker
      ansible.builtin.systemd:
        name: docker
        state: started

    - name: Wait for kind node container
      ansible.builtin.command: docker inspect -f '{{ '{{' }}.State.Running{{ '}}' }}' {{ kind_cluster }}-control-plane
      register: kind_running
      changed_when: false
      retries: 12
      delay: 5
      until: kind_running.stdout == 'true'

    # ---- verification -----------------------------------------------------------
    - name: Verify solana dir is ZFS
      ansible.builtin.shell:
        cmd: set -o pipefail && findmnt -n -o FSTYPE {{ kind_solana_dir }} | grep -q zfs
        executable: /bin/bash
      changed_when: false

    - name: Verify ramdisk is tmpfs
      ansible.builtin.shell:
        cmd: set -o pipefail && findmnt -n -o FSTYPE {{ ramdisk_mount }} | grep -q tmpfs
        executable: /bin/bash
      changed_when: false

    - name: Verify zvol is gone
      ansible.builtin.command: zfs list -H -o name {{ zvol_dataset }}
      register: zvol_gone
      failed_when: zvol_gone.rc == 0
      changed_when: false

    - name: Migration complete
      ansible.builtin.debug:
        msg: >-
          Storage migration complete.
          {{ kind_solana_dir }} is now ZFS dataset {{ new_dataset }}.
          Ramdisk at {{ ramdisk_mount }} (tmpfs, {{ ramdisk_size }}).
          zvol {{ zvol_dataset }} destroyed. Data intentionally not copied
          (stale) — download fresh snapshot on next start.
          Next: biscayne-sync-tools.yml --tags build-container, then
          biscayne-recover.yml.