jakman85andClaude Opus 5 04606d48b2 docs(vpn): stop crediting the nftables kill-switch for a drop it never makes
Four places in the tree told the reader that the host nftables table is the
authoritative fail-closed backstop for egress-class=vpn pods: platform/vpn-egress
README, egress-steering.yaml, the role README, and the vpn-killswitch test's own
GIVEN/THEN prose. It is not, and cannot be — Cilium's eBPF egress-gateway
datapath bpf_redirect()s those skbs to the egress device without invoking
netfilter POSTROUTING. Corrected with the measurement in each place rather than
softened, because a guard the repo trusts and that does not fire is worse than no
guard.

What replaces the claim, everywhere: vpn-class fails closed because CILIUM drops
the traffic when it cannot use its cached egress interface, verified by tcpdump on
both the WAN and tun0 during a tunnel stop and a tunnel restart (0 packets out
either). The nft table keeps a narrower, now-proven job: node-originated traffic
sourced from a tunnel address (killswitch_drop moved 0 -> 3 packets on
k3s-prod-3 when such a packet was routed at the WAN).

Also recorded:

* egress-steering.yaml — `interface: tun0` is resolved ONCE and cached, and the
  gateway node is what tells Cilium it changed (the egress-uplink node label). A
  future reader's instinct will be to have the node write to that object; the
  comment says not to, because it is Flux-managed, and points at the label and
  `cilium-dbg bpf egress list` as the debugging entry points instead.
* egress-steering.yaml — why the new NFS media mounts are not affected by
  pod-scoped steering: an NFS PV is mounted by the node kernel in the host netns,
  so podSelector never matches it. The 192.168.0.0/16 exclusion covers the server
  too, but that is the second reason, not the first.
* vpn-killswitch test — its recovery step depends on the re-steer path, and could
  not have passed before it existed. Its no-leak assertion was always right; only
  the explanation was wrong. Also states the prerequisite plainly: the test cannot
  run at all without a labelled gateway node.
* platform README — prod is live on k3s-prod-3 with the before/after egress IPs,
  and the note that prod's vpn-class pods had NO internet beforehand (CEGP with no
  matching node -> `Gateway IP: Not Found` -> dropped), so arming the gateway
  restored egress rather than moving it off the WAN.
* role README — the standing "add the shared fwmark to the interface contract"
  escalation is closed as not implementable on Cilium OSS, rather than left open
  for someone to attempt.

DECISIONS-LOG carries the full session entry, including the drafted ADR-0015 /
docs-03 amendment for the architect (specs are immutable to agents) and the five
things left for the operator — chief among them that a silent gateway outage still
has no alert, which is what let the dev gateway sit dead for 80 minutes.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-12 17:57:52 -05:00

home-network-k3s-impl

Implementation of the home k3s + Longhorn platform. This repo holds the reconciled artifacts (Flux config, Kustomize overlays, KubeVirt/Helm manifests, ServiceDefinitions, Kyverno policies, Chainsaw conformance tests, CI). It is driven by — and subordinate to — the read-only specification at ../home-network-k3s.

Rules (from the spec — non-negotiable)

  • The spec is read-only. Never modify anything under ../home-network-k3s. Implement against it; escalate spec problems, don't edit them (spec AGENTS.md §11, R-TEST-06).
  • Done = a green, reproducible, requirement-tagged conformance test — never "merged," never a manual demo (spec docs/14, agents/definition-of-done.md).
  • No work on main. Every change is a feature branch merged into main (spec CONTRIBUTING.md).
  • No plaintext secrets — SOPS-encrypted only (spec docs/07).
  • Phase discipline — only build what the active roadmap phase authorizes (spec roadmap/phases.md).

Layout

infra/          node provisioning: OpenTofu (Proxmox VE) + cloud-init + Ansible, and the
                pinned dev container that carries the whole toolchain
bootstrap/      one-time cluster bootstrap: Flux install, SOPS/age key, host Gitea
platform/       platform CONTROLLERS (Flux HelmReleases / operator bases): kyverno, cilium,
                longhorn, external-snapshotter, cert-manager, externaldns, gateway, coredns,
                vpn-egress, monitoring, cnpg, keycloak, oauth2-proxy, kubevirt
platform-config/ platform CONFIGS — the custom resources of the CRDs installed above
                (ClusterIssuers, Gateway, Kyverno policies, KubeVirt/CDI CRs, Keycloak CRs).
                Split out because CRs and the CRDs they use cannot apply in one pass.
apps/           application tier, reconciled as dependency-ordered WAVES:
                  wave-0/ wave-1/ wave-2/   rendered container apps (see DESIGN-waves.md)
                  vms/                      KubeVirt VirtualMachines (non-gating tier)
catalog/        ServiceDefinition entries (the onboarding surface) + render.py
schemas/        ServiceDefinition JSON Schema + renderer contract
clusters/       Flux entrypoints + dev/ and prod/ overlays
conformance/    Chainsaw behavior/conformance suite + harness + coverage report
ci/             the gate as scripts (lint · schema · Kyverno L0 · L1 render · decision)
.gitea/         Gitea Actions CI running that gate on an in-cluster runner

Status

Roadmap phases 0–6 are delivered and deployed on the dev cluster; Phase 7 (prod) is not open — clusters/prod is a design-only overlay.

Phase Delivered
0 Foundations ServiceDefinition schema + renderer, Kyverno L0 gate, conformance harness, CI
1 Cluster bring-up 3-node k3s HA on Proxmox VE (192.168.1.50/.51/.52), Cilium, Flux, SOPS
2 Platform core Cilium · Longhorn · cert-manager (LE-prod wildcard) · ExternalDNS · Gateway API · split-horizon CoreDNS
3 Egress / VPN ADR-0015 node-level OpenVPN split-tunnel + Cilium egress-gateway steering + host kill-switch
4 Observability kube-prometheus-stack · Loki · Alloy · Alertmanager. Velero still blocked on OQ-BKP; image-automation authored but disabled
5 IaaS KubeVirt + CDI on real nested KVM; live-migratable RWX VM storage. The UniFi VM runs, but UniFi OS Server is not yet installed in the guest
6 Identity + CI Keycloak (Operator + CNPG) · oauth2-proxy forward-auth · Grafana OIDC · kubectl OIDC SSO with group→RBAC · in-cluster Gitea Actions merge gate

Conformance: 36 / 51 requirements covered (70.6%), 15 gaps, 1 safety-critical gap (R-STATE-02, Longhorn node-loss). Regenerate with ./conformance/run.sh --coverage-only; the full report is conformance/_artifacts/coverage/coverage.md.

The running narrative — decisions, root causes, incidents, follow-ups — is DECISIONS-LOG.md. It, not this table, is the authoritative record.

Working on this repo

Everything the gate needs is baked into the pinned dev container — do not install the toolchain on the host:

infra/devcontainer/dev.sh build            # once
infra/devcontainer/dev.sh run make -C ci gate   # the same gate CI runs
infra/devcontainer/dev.sh                  # interactive shell (sops, flux, kubectl, tofu, ansible)

The container mounts the repo at /work, your age keyring, and the sibling spec repo read-only so the spec-immutability check can actually run. See infra/devcontainer/README.md.

A green run prints MERGE GATE: PASS. The L2/L3 conformance layers stay SKIPPED unless CLUSTER_AVAILABLE=true — the static gate never pretends to have run them.

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