k8s-starter-pack/talos/patch-longhorn.yaml

# Prepares each dedicated worker for Longhorn (apps/longhorn.yaml) — the
# storage layer this repo ships pre-installed. Applied to worker.yaml only;
# the three Raspberry Pi control-plane nodes do not provide application
# storage.
#
# This file has TWO documents (separated by `---`), because it's making two
# different kinds of change: a patch to the normal machine config, and a
# standalone Talos resource that doesn't live inside `machine:`/`cluster:`
# at all.
#
# --- Document 1: mount the volume into the kubelet's view ---
# Talos runs the kubelet in its own isolated mount namespace. Without this,
# a volume mounted at /var/mnt/longhorn on the node itself would be
# invisible to any Pod using a hostPath-style mount there — which is
# exactly how Longhorn's own manager and engine Pods access node storage.
# This bind-mounts that same path into the kubelet's namespace so Pods can
# actually see it. `rshared` matters specifically: it lets mounts Longhorn
# creates later *underneath* this path (one per volume) propagate back out
# to the host, instead of being invisible outside the container that made
# them.
#
# --- Document 2: UserVolumeConfig ---
# A Talos UserVolumeConfig tells Talos itself to find, format, and mount a
# disk — no manual partitioning on your part. `diskSelector.match:
# '!system_disk'` means "any disk that isn't the one Talos is installed
# on" (never touches your OS disk), and `minSize: 300GiB` means "only
# consider disks at least that large." Each worker has one 350GiB data disk
# and one 20GiB system disk, so this admits the intended data disk while
# rejecting the boot disk.
# `grow: false` keeps the volume at its initial size even if the
# underlying disk is later resized — deliberate here, so growing storage
# is always a conscious decision (see docs/09-growing-up.md).
#
# The `name: longhorn` below is what determines the mount path Talos uses
# — user volumes are always mounted at /var/mnt/<name>, which is why
# Document 1 above and apps/longhorn/values.yaml both hardcode
# /var/mnt/longhorn. Renaming this would mean updating both.
#
# >> Ask Claude: "how do I find out which of my disks Talos will actually
#    pick for this?" before you boot for real — worth confirming on your
#    specific hardware rather than assuming.
machine:
  kubelet:
    extraMounts:
      - destination: /var/mnt/longhorn
        type: bind
        source: /var/mnt/longhorn
        options:
          - bind
          - rshared
          - rw
---
apiVersion: v1alpha1
kind: UserVolumeConfig
name: longhorn
provisioning:
  diskSelector:
    match: "!system_disk"
  minSize: 300GiB
  grow: false