jakman85andClaude Opus 5
fdc4a7d9f4
During the substitution incident a bad render (k8sServiceHost: "") took down TWO of three
Cilium agents simultaneously. The agents' `config` init container falls back to the API
ClusterIP, which only the Cilium agent itself can translate — and that agent is the one
being replaced — so it deadlocks on `dial tcp 10.43.0.1:443: i/o timeout`.
Root cause of the 2-at-once: `updateStrategy.rollingUpdate.maxUnavailable: 2` is the
UPSTREAM CHART DEFAULT, confirmed by downloading cilium-1.20.1.tgz and reading
values.yaml:437-444 — not a local choice, and not overridden anywhere in this repo.
maxUnavailable: 1 makes a rollout replace ONE agent at a time and stop at the first pod
that fails to become Ready. The whole value of the setting is that the rollout halts on
the first bad node instead of taking the majority of the dataplane with it, and that
guarantee only exists at 1. It matters far more on a cold PROD bootstrap, where there is
no healthy peer to recover from — dev only self-healed because k3s-dev-3 kept a working
agent throughout.
Set as a [parity] field in ALL THREE places, per this repo's documented contract that the
Ansible bootstrap values and the Flux HelmRelease values must agree on settings that
define cluster networking (Ansible installs Cilium at bootstrap; the HelmRelease adopts
it; the two layers fight otherwise):
platform/cilium/helmrelease.yaml (authoritative for Flux)
infra/ansible/roles/cilium/templates/cilium-values.yaml.j2 (authoritative for bootstrap)
platform/cilium/values.yaml (reference mirror, kept in sync)
Verified by rendering the .j2 with roles/cilium/defaults and diffing full value sets: every
[parity] field is byte-equal across all three; only k8sServiceHost differs, as designed
(${K3S_API_HOST} vs {{ k3s_api_host }}).
MERGING THIS IS NON-DISRUPTIVE. updateStrategy lives at DaemonSet.spec.updateStrategy — a
SIBLING of spec.template (chart daemonset.yaml:49-53). The DaemonSet controller decides a
pod is out of date by hashing spec.template alone, so the pod-template hash does not move,
no new ControllerRevision is created, and zero pods are recreated. Helm patches the field
in place. (If it were disruptive it would be self-defeating: rolling agents under the old
maxUnavailable: 2 in order to install maxUnavailable: 1.) Verify after reconcile with
`kubectl -n kube-system get ds cilium -o jsonpath='{.spec.updateStrategy.rollingUpdate.maxUnavailable}'`
plus unchanged pod ages — that is the cleanest proof nothing rolled.
Trade-off recorded in the comments: upgrades serialise, roughly two waves to three at 3
nodes (a minute or two). On a large cluster this becomes painful and a percentage such as
"10%" would be right — noted so a future larger cluster revisits it deliberately.
SCOPE: this bounds blast radius, it does NOT close the substitution race. A bad render
still ships; it now breaks one node and stalls rather than taking the majority.
platform.dependsOn: [flux-system] (P0) is the fix for the cause.
Serves: R-PLAT-01, R-NET-01.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
infra/ — node provisioning and the toolchain
OpenTofu (Proxmox VE) + cloud-init + Ansible bring up the 3-node k3s/Cilium dev cluster.
Spec: ../home-network-k3s/docs/02-environments-and-provisioning.md.
| Path | What |
|---|---|
tofu/ |
The "Create" stage: 3 cloud-init'd VMs on the Proxmox box (bpg/proxmox provider) |
cloud-init/ |
First-boot baseline shipped as a Proxmox user-data snippet |
ansible/ |
The "Baseline"/"Configure" stages: k3s HA, Cilium, kube-vip, the VPN egress gateway |
devcontainer/ |
The pinned toolchain (tofu, ansible, sops, age, flux, kubectl, helm and the whole CI gate toolchain) |
cluster.sh |
RETIRED — drove the old libvirt VMs; does not work against Proxmox |
PHASE1-STATUS.md |
Current state of the cluster and how to reconnect to it |
PHASE1-SCOPE.md |
Historical Phase-1 scoping doc (libvirt era — superseded) |
Where the cluster actually lives
The dev cluster is not on this workstation. It runs on a Proxmox VE host; the nodes sit on the Proxmox LAN and are reached across a pfSense NAT:
| Nodes | k3s-dev-1/2/3 at 192.168.1.50/.51/.52 — 6 vCPU, 24 GiB, Debian 13, k3s v1.36.4 |
| kube-API | kube-vip VIP 192.168.1.49:6443, reached from the workstation via NAT 192.168.2.50:6443 |
| Node SSH | pfSense NAT 192.168.2.102:2250/2251/2252 → node :22 (Ansible only) |
| Ingress VIP | 192.168.1.53 (Cilium L2, shared Gateway); .53–.60 reserved for LB VIPs |
The earlier libvirt/KVM cluster on 10.73.0.0/24 is retired. Any doc or command referencing
virsh, qemu:///system, or 10.73.0.x for the cluster is historical.