# StorageClass for the persistent buildkit cache.
# - numberOfReplicas: 1 -> the cache is written ONCE across the cluster (1x disk,
#   NOT the 3x triple-replication of the default 'longhorn' SC). This is deliberate:
#   a buildkit cache is throwable/recreatable, so replicating it 3x wastes disk that
#   node 2 (already 76%) can't afford. 1 replica survives single-node loss via
#   dataLocality: best-effort (re-replicates only when a node actually dies).
# - dataLocality: best-effort -> keep the single replica on the same node as the
#   pod (fast local reads), replicate only if that node fails.
# Auto-revert safety net: the buildkit-cache-monitor cron reverts buildkit to the
# ephemeral (no-PVC) driver if any node crosses the critical disk threshold.
# See monitoring/buildkit-cache-monitor.sh.
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: buildkit-single-1r
  annotations:
    description: "Single-replica Longhorn (buildkit cache) - 1x disk, durable across node loss"
provisioner: driver.longhorn.io
allowVolumeExpansion: true
reclaimPolicy: Delete
volumeBindingMode: Immediate
parameters:
  numberOfReplicas: "1"
  staleReplicaTimeout: "30"
  fsType: "ext4"
  dataLocality: "best-effort"
  dataEngine: "v1"