etcd's 2 GiB quota was reached on 2026-10-07 (backend 2.1 GiB, ~73 days of
churn). etcd raised NOSPACE and refused all writes, so kubelets could not post
node status: three nodes went NotReady and the tunnel origin pods on them
disappeared. Recovery was compact + defrag + alarm disarm per member.
The apiserver compacts every 5m, but compaction never shrinks the backend file -
only a defrag returns space, and nothing scheduled it. This adds:
- CronJob etcd-defrag (kube-system, Sundays 03:00): compact to the current
revision, defrag each member sequentially, disarm NOSPACE, print before/after.
- Secret etcd-defrag-creds (SOPS/ksops, k8s/argocd/secrets): etcd CA plus a
CN=etcd-defrag client cert signed by the cluster's etcd CA (expires 2036-10).
Applied by the existing apps: cluster-maintenance (directory) and 00-secrets
(ksops generator).