devmapper-pool.yaml

# Extension service: creates dm-thin-pool before CRI loads devmapper snapshotter
# Talos discovers this at /usr/local/etc/containers/devmapper-pool.yaml
name: devmapper-pool
depends:
  # Only wait for the raw partition — start ASAP to create pool before CRI reads config.
  # DO NOT depend on containerd (CRI) — we need to finish BEFORE CRI initializes plugins.
  - path: /dev/disk/by-partlabel/r-dm-data
container:
  entrypoint: /bin/busybox
  args:
    - sh
    - /devmapper-pool-init
  mounts:
    # Host dmsetup binary (only tool Talos provides)
    - source: /sbin/dmsetup
      destination: /sbin/dmsetup
      type: bind
      options: [bind, ro]
    # Block devices + partlabel symlinks
    - source: /dev
      destination: /dev
      type: bind
      options: [rshared, rbind, rw]
    # /run is tmpfs — always writable, always available at boot, shared with host.
    # Used for devmapper metadata (rebuilt each boot).
    - source: /run
      destination: /run
      type: bind
      options: [rshared, rbind, rw]
    # /var mount kept for reboot marker and CRI overlay write (best-effort)
    - source: /var
      destination: /var
      type: bind
      options: [rshared, rbind, rw]
    # Required for finding host CRI PID and sysrq-trigger reboot fallback
    # Must be rw for sysrq-trigger writes
    - source: /proc
      destination: /host-proc
      type: bind
      options: [rbind, rw]
    # Required libs for dmsetup
    - source: /lib
      destination: /lib
      type: bind
      options: [rbind, ro]
  security:
    writeableRootfs: true
restart: never