fix(vpn-ingress): content-hash the peer register, or a merged peer never reaches the tunnel

The operator enrolled a phone, merged the peer, and `wg show` listed none.
Measured on prod 2026-10-06 with the peer already on main:

  live wg-peers ConfigMap, active AllowedIPs .. 0
  DaemonSet volume reference ................. configMap.name: wg-peers (FIXED)
  DaemonSet generation/observedGeneration .... 1 / 1   (never rolled)
  init container, all three pods ............. "0 peer(s)"

Part of it was just the 10m reconcile interval. The defect is the fixed name:
Flux updates a fixed-name ConfigMap IN PLACE, so the pod template is
byte-identical, so no rollout is triggered -- and the init container assembles
wg0.conf ONCE at pod start into a tmpfs, so the running tunnel keeps the old
peer list indefinitely. Adding or revoking a peer had no effect until something
unrelated restarted the pods. For a REVOCATION that is a security defect, not
an inconvenience: delete a stanza, see a green PR, device keeps working.

The runbook and README both claimed "PR -> merge -> Flux rolls the DaemonSet".
Never true. And this repo already documents the fix, in a file I had read --
runbooks/kustomization.yaml: "The generated name carries kustomize's content
hash, so editing any runbook rolls the server automatically and a stale
projection is impossible."

So: peers.yaml (inline ConfigMap) -> peers.conf (plain file) + a
configMapGenerator. The operator's enrolled peer is carried across verbatim.
Every line is WireGuard config and `#` is a legal comment there, so the
documentation now lives inside the file that is actually mounted.

`namespace: vpn-ingress` on the kustomization is REQUIRED, not tidiness: a
generated ConfigMap inherits no namespace, everything else here declares
vpn-ingress, and kustomize's nameReference will not rewrite across a namespace
boundary -- without it the build mounts the unhashed name and the pods wedge on
a missing volume. Caught only by building the output and reading the volumes.

new-peer.sh: PEERS_FILE repointed, and a missing register is now FATAL rather
than skipped -- the old `[ -r "$PEERS_FILE" ] && grep ...` guard meant that
after the rename the only symptom would have been duplicate detection quietly
never firing again. Stale peers.yaml references swept from six files including
the script's own user-facing output.

Verified: the DaemonSet now mounts wg-peers-m9kcckcb5t; the hash tracks content
(edit -> dgg7ht9c74 -> restore -> m9kcckcb5t); the enrolled peer is byte-identical
to main's; and `new-peer.sh dupe 2` is now correctly refused by the operator's
real allocation.

No sensitive paths; merges on a green gate.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

decisions/2026-10-06-new-peer-ignores-template-comments.md

@@ -0,0 +1,73 @@
+---
+date: 2026-10-06
+branch: fix/new-peer-ignores-template-comments
+title: new-peer.sh refused the first VPN address because its duplicate check matched its own commented-out example
+---
+
+## What changed
+
+The operator's first real enrolment failed:
+
+```
+$ ./infra/vpn-ingress/new-peer.sh keith-phone 2
+new-peer.sh: 10.90.0.2/32 is already allocated in platform/vpn-ingress/peers.yaml. Pick another octet.
+```
+
+**Nothing was allocated.** `peers.yaml` had zero peers — the pod's own init container reported
+`wg0.conf assembled: 0 peer(s)`. The duplicate-address check grepped the WHOLE file, and
+`peers.yaml` line 66 is a **commented-out example stanza** I wrote, containing literally
+`#   AllowedIPs = 10.90.0.2/32`. So `.2` — the first address anybody would ask for, and the one my
+own runbook uses in its example — was permanently un-allocatable, with a message asserting the
+opposite of the truth.
+
+Both halves fixed, because either alone leaves the trap half-set:
+
+- **`infra/vpn-ingress/new-peer.sh`**: the check strips comment lines before matching
+  (`grep -vE '^[[:space:]]*#' | grep -q …`). That is the correct predicate rather than a patch: a
+  real stanza's `AllowedIPs` line is never commented, while both the template and every peer's
+  `# <name> — <owner>` label always are.
+- **`platform/vpn-ingress/peers.yaml`**: the example now uses placeholders that cannot match
+  anything real — `# <device-name> — <owner>, enrolled <YYYY-MM-DD>` and
+  `AllowedIPs = 10.90.0.<octet>/32`. A future grep cannot be fooled by it either.
+
+The bug class is worth naming: **a documentation example that is byte-identical to real data will
+eventually be parsed as real data.** The same shape caused two earlier defects in this component —
+`flux-postbuild-substitution` flagged a `${...}` written inside a comment *explaining* that hazard,
+and `no-plaintext-secrets` flagged the `.sops.yaml.example` because the kustomization named it in a
+comment. Three instances now; the rule is to make examples structurally unmatchable, not merely
+commented out.
+
+No sensitive paths (`platform/vpn-ingress/**`, `infra/vpn-ingress/**`, `decisions/**`), so this
+merges on a green gate with no override.
+
+## What I verified
+
+Run in the pinned toolbox against the live tree, 2026-10-06.
+
+- **`.2` now works**, and it went through the REAL key path: `new-peer.sh keith-phone 2` rendered a
+  profile with `Address 10.90.0.2/32`, `AllowedIPs = 10.90.0.2/32` in the printed stanza, full
+  tunnel, at `.cache/wg-peers/keith-phone.conf` (0600). The throwaway keypair was deleted after.
+- **This incidentally closes a gap left open in #60**: the profile could only have been rendered by
+  deriving the server's public key via `sops -d --extract … | wg pubkey` from
+  `wg-server-key.sops.yaml` — so that pipeline is now proven **against the operator's real key**,
+  not just against a placeholder it was expected to reject.
+- **A real duplicate is still refused.** Appending an uncommented
+  `AllowedIPs = 10.90.0.5/32` stanza and asking for octet 5 produced the correct refusal; the tree
+  was restored afterwards and `git diff --stat` showed only the intended template edit.
+- **Zero active allocations remain**: `grep -vE '^[[:space:]]*#' peers.yaml | grep -c AllowedIPs`
+  → `0`.
+- **Toolbox gate**: rc 3, with `spec-immutability`, `decisions-log`, `lint`, `l0`, `render-golden`,
+  `l1` and `approval-policy` all pass; rc 3 is the two environmental skips (`gitea-settings`,
+  conformance L2/L3). **Not green. Reported as rc 3.**
+
+## What I did NOT verify
+
+- **No peer is enrolled by this branch.** The keypair I generated was a throwaway and was deleted;
+  the operator must run the script themselves, since the device's private key must exist only on
+  the device. So the end of the enrolment path — a stanza merged into `peers.yaml`, Flux rolling
+  the DaemonSet, and `wg show` listing a peer — is still unexercised.
+- **The duplicate-NAME warning** (`grep -qi "^ *# *${NAME} "`) deliberately still inspects
+  comments, because per-peer labels are comments. It is no longer tripped by the template, but I
+  did not test it against a real enrolled peer.
+- **Nothing about client traffic.** The WAN port-forward is still not configured and there is still
+  no off-LAN vantage point, so the tunnel has carried no packet.

decisions/2026-10-06-peers-configmap-content-hash.md

@@ -0,0 +1,103 @@
+---
+date: 2026-10-06
+branch: fix/peers-configmap-content-hash
+title: A merged VPN peer never reached the tunnel — the peer register was a fixed-name ConfigMap, so nothing rolled the pods
+---
+
+## What changed
+
+The operator enrolled a phone, merged the peer, and **`wg show` listed no peers.** Measured on prod
+2026-10-06, with the peer already on `main`:
+
+| observation | value |
+|---|---|
+| peer stanza on `main` | present (`AllowedIPs = 10.90.0.2/32`) |
+| GitRepository artifact | `main@sha1:e1bebb8` — Flux had fetched it |
+| `vpn-ingress` Kustomization `lastAppliedRevision` | `main@sha1:5928d81` — **behind**, 10m interval |
+| live `wg-peers` ConfigMap, active `AllowedIPs` lines | **0** |
+| DaemonSet volume reference | `configMap.name: wg-peers` — a **fixed** name |
+| DaemonSet `generation` / `observedGeneration` | **1 / 1** — it had **never rolled** |
+| init container, all three pods | `wg0.conf assembled: 0 peer(s)` |
+
+The lag was only the reconcile interval. **The defect is the fixed name.** When Flux does update a
+fixed-name ConfigMap it updates it *in place*: the DaemonSet's pod template is byte-identical, so
+no rollout is triggered — and because the init container assembles `wg0.conf` **once at pod start**
+into a tmpfs, the running tunnel keeps the old peer list indefinitely. Adding or revoking a peer
+would have had **no effect at all** until something unrelated happened to restart the pods. For a
+*revocation* that is a security defect, not an inconvenience: the operator would delete a stanza,
+see a green PR, and the device would keep working.
+
+My runbook and README both asserted "PR → merge → Flux rolls the DaemonSet (~1 min)". That was
+never true.
+
+**This repo already documents the fix, and I had read the file.** `runbooks/kustomization.yaml`:
+*"The generated name carries kustomize's content hash, so editing any runbook rolls the server
+automatically and a stale projection is impossible."*
+
+So the register becomes a **content-hashed generator**:
+
+- `platform/vpn-ingress/peers.yaml` (inline ConfigMap) → **`platform/vpn-ingress/peers.conf`**, a
+  plain file, plus a `configMapGenerator` in `kustomization.yaml`. The operator's enrolled peer was
+  carried across verbatim. Every line is WireGuard config and `#` is a legal comment there, so the
+  documentation now travels *inside the mounted file* instead of in a YAML wrapper that gets
+  stripped.
+- **`namespace: vpn-ingress` added to the kustomization — REQUIRED, not tidiness.** A generated
+  ConfigMap inherits no namespace; every other object here declares `vpn-ingress`; and kustomize's
+  `nameReference` transformer will not rewrite a reference across a namespace boundary. Without it
+  the build emitted `ConfigMap wg-peers-m9kcckcb5t` while the DaemonSet still mounted the unhashed
+  `wg-peers`, which would not exist — the pods would wedge on a missing volume. I caught this only
+  by building the output and reading the volumes block.
+- **`infra/vpn-ingress/new-peer.sh`**: `PEERS_FILE` repointed to `peers.conf`, and a missing
+  register is now **fatal** instead of skipped. The old guard was
+  `[ -r "$PEERS_FILE" ] && grep …`, so after the rename the only symptom would have been
+  duplicate-address detection quietly never firing again — the silent-skip shape this repo treats
+  as a defect in its own right.
+- Stale `peers.yaml` references swept from the README, runbook, `daemonset.yaml`,
+  `networkpolicy.yaml`, the SOPS example, and the script's own **user-facing output** (it told the
+  operator to paste into "peers.yaml, under data.peers.conf", which would no longer exist).
+- The runbook gained the verification that actually distinguishes this failure — the DaemonSet's
+  `generation` must *increase* after the merge — and a troubleshooting row for `0 peer(s)` after a
+  merge.
+
+Flux's `prune: true` removes the orphaned fixed-name `wg-peers` ConfigMap on the next reconcile.
+
+No sensitive paths (`platform/vpn-ingress/**`, `infra/vpn-ingress/**`, `runbooks/**`,
+`decisions/**`), so this merges on a green gate with no override.
+
+## What I verified
+
+Built and run in the pinned toolbox, 2026-10-06 (kustomize v5.8.1 via `kubectl kustomize`).
+
+- **The reference is now rewritten end to end**: generated `ConfigMap wg-peers-m9kcckcb5t` in
+  namespace `vpn-ingress`, and the DaemonSet mounts **`wg-peers-m9kcckcb5t`**. Before adding
+  `namespace:` the same build mounted the unhashed `wg-peers` — so the namespace line is load
+  bearing, measured both ways.
+- **The hash tracks content, which is the whole mechanism.** `wg-peers-m9kcckcb5t` →
+  append a second peer → `wg-peers-dgg7ht9c74` → restore → `wg-peers-m9kcckcb5t`. Deterministic
+  and reversible, so an edit necessarily changes the pod template.
+- **The operator's enrolled peer survived the file conversion byte-for-byte**: the active stanza in
+  `peers.conf` (`PublicKey = pBRSHrRy…`, `AllowedIPs = 10.90.0.2/32`) is identical to the one on
+  `main`, compared directly against `git show origin/main:platform/vpn-ingress/peers.yaml`.
+- **The build still emits all five objects**: Namespace, ConfigMap, Secret, DaemonSet,
+  NetworkPolicy — and the `Namespace` object's own name is still `vpn-ingress` (the namespace
+  transformer did not rewrite it).
+- **`new-peer.sh` works against the new register**: `spare-laptop 7` renders a profile and prints
+  "append this to platform/vpn-ingress/peers.conf"; `dupe 2` is **refused** because the operator's
+  real `.2` now occupies it — the first time the duplicate check has been exercised against real
+  data rather than against its own example.
+- **Toolbox gate**: rc 3, with `spec-immutability`, `decisions-log`, `lint`, `l0`, `render-golden`,
+  `l1` and `approval-policy` all pass; rc 3 is the two environmental skips. **Not green. Reported
+  as rc 3.**
+
+## What I did NOT verify
+
+- **That the roll actually happens on the cluster.** The whole point of the change is unproven
+  until Flux applies it: the success criterion is the DaemonSet's `generation` increasing and
+  `wg0.conf assembled: 1 peer(s)` in the init log, followed by `wg show` listing the peer.
+- **That the tunnel then carries traffic.** No handshake has ever been observed. The WAN
+  port-forward is reportedly configured but has never been exercised by a packet I can see, and I
+  have no off-LAN vantage point — runbook step 6 from cellular remains the only honest test.
+- **Revocation**, which is the case where this defect was a security problem. Deleting a stanza
+  should now roll the pods and drop the peer; untested.
+- **Whether the orphaned fixed-name `wg-peers` ConfigMap is actually pruned.** Reasoned from
+  `prune: true` on the Kustomization, not observed.

decisions/2026-10-06-vpn-ingress-ip-forward.md

@@ -0,0 +1,113 @@
+---
+date: 2026-10-06
+branch: fix/vpn-ingress-ip-forward
+title: The VPN tunnel never came up — a hostNetwork pod cannot write net.ipv4.ip_forward, and wg-quick treats a failed PostUp as fatal
+---
+
+## What changed
+
+The remote-access VPN reconciled for the first time with a real server key (#60 then #62) and
+**the tunnel did not come up**. One line in my own manifest was the whole cause.
+
+Measured in the `wireguard` container on prod, 2026-10-06:
+
+```
+[#] ip link add dev wg0 type wireguard
+[#] wg addconf wg0 /dev/fd/63
+[#] ip -4 address add 10.90.0.1/24 dev wg0
+[#] ip link set mtu 1420 up dev wg0
+[#] sysctl -q -w net.ipv4.ip_forward=1
+sysctl: permission denied on key "net.ipv4.ip_forward"
+[#] ip link delete dev wg0
+**** Tunnel /config/wg_confs/wg0.conf failed, will stop all others! ****
+```
+
+Everything up to that point worked. **The cause is not a missing capability.** With
+`hostNetwork: true` the runtime mounts `/proc/sys` **read-only** in the container — confirmed in the
+pod's own `/proc/mounts`: `proc /proc/sys proc ro,nosuid,nodev,noexec,relatime` — precisely because
+those sysctls are the *host's* globals and a container must not rewrite them. `CAP_NET_ADMIN` cannot
+lift a read-only mount, so this can never succeed from here. And `wg-quick` treats any failed
+`PostUp` as fatal, so it deleted the interface it had just finished building.
+
+**The line was never needed.** `node_baseline` writes `net.ipv4.ip_forward=1` to
+`/etc/sysctl.d/99-k3s-cilium.conf`, and reading the value from inside the pod returns `1`. I had
+written the header comment *correctly* — "ip_forward is ALREADY 1 on these nodes … so no pod sysctl
+is needed" — and then emitted the sysctl anyway, justified in its own comment as "re-asserted so
+this component does not silently depend on another role's sysctl file surviving". That defensive
+re-assertion is the entire outage. **The lesson is narrow and reusable: in a hostNetwork pod,
+verify host state, never write it.**
+
+Fix:
+
+- **`platform/vpn-ingress/daemonset.yaml`**: the `PostUp = sysctl …` line is gone, replaced by a
+  **read** in the init container — `grep -qx 1 /proc/sys/net/ipv4/ip_forward` — which fails closed
+  with a message naming the `node_baseline` role. Reading `/proc/sys` is permitted; only writing is
+  not. Fail-closed still matters: a tunnel that comes up but cannot forward would satisfy every
+  probe in this component and silently drop every client's traffic.
+- The header bullet that said "no pod sysctl is needed" now also says **do not attempt one**, with
+  the mechanism, so the next author does not re-add it for the same reason I did.
+- The `securityContext` comment claimed NET_ADMIN was for "create the wg0 link, set the host sysctl,
+  and write the netfilter rules". The middle clause was false; corrected.
+- The image's `chown: … Operation not permitted` startup run — plus its own "Permissions could not
+  be set … we will not provide support for it" — is now documented as **expected and harmless**, in
+  both the manifest and the runbook, so nobody chases it. Capabilities are dropped to `NET_ADMIN`
+  only, so its s6 init has no `CAP_CHOWN`; `/config` is a writable tmpfs, everything runs as root,
+  and `wg-quick` proceeds past it (as it did here — the failure was 30 lines later).
+- **`runbooks/vpn-remote-access.md`**: a "what a healthy start looks like" block with the real log
+  lines; `ip_forward is 0` added to the init-failure table; and the note that `0/1 Running` with
+  `Startup probe failed: Unable to access interface: No such device` is the signature of `wg-quick`
+  tearing the tunnel down — read the `[#]` line it died on.
+- **`platform/vpn-ingress/README.md`**: a table of what the first reconcile settled (below).
+
+No sensitive paths: `platform/vpn-ingress/**`, `runbooks/**` and `decisions/**` only. This merges on
+a green gate with no override.
+
+## What I verified
+
+Live prod, read-only, 2026-10-06. **Four questions this component's design rested on are now
+measured rather than assumed — three went the right way, one was the defect above.**
+
+- **The GitOps path is proven end to end.** `Kustomization vpn-ingress` `lastAppliedRevision:
+  main@sha1:cf7d5e4` equals the GitRepository artifact revision. The Secret carries
+  `kustomize.toolkit.fluxcd.io/name: vpn-ingress`, so Flux delivered it.
+- **SOPS decryption works, proven by digest rather than by eye.** The value in
+  `platform/vpn-ingress/wg-server-key.sops.yaml` on `main`, decrypted, is 44 bytes, is **not** the
+  placeholder, and **`wg pubkey` accepts it**. Its SHA-256 equals the SHA-256 of the live Secret's
+  decoded `data.privatekey` (`d7c8f8de6f252649…` both sides). No key material was printed at any
+  point — lengths, booleans and digests only.
+- **The `wg pubkey` guard fired correctly, and its `ENC[` branch was never needed.** During the
+  kubelet window before the updated Secret propagated, all three pods reported *"It is still the
+  committed REPLACE-ME PLACEHOLDER"* — the guard distinguishing a stale/unfilled value from
+  ciphertext, exactly as designed. It cleared on its own once the mount refreshed; **a transient
+  `REPLACE-ME` CrashLoop for a minute or two after the key PR merges is expected, not a fault.**
+- **The kernel module reaches the pod**: `ip link add dev wg0 type wireguard` succeeded and
+  `/proc/modules` lists `wireguard`. So the `node_baseline` addition works and `CAP_SYS_MODULE` is
+  correctly not required.
+- **`allowPrivilegeEscalation: false` does NOT break the image's s6 init** — the container reaches
+  `wg-quick` normally. The flag stays; the fear recorded in #55 is closed.
+- **The iptables backends MATCH, which was my single biggest documented doubt.** The image ships
+  `iptables v1.8.13 (nf_tables)` via `/usr/sbin/xtables-nft-multi`, and Debian 13 is nf_tables. The
+  nightmare case — rules accepted into a table the kernel never consults, so handshakes succeed and
+  every forwarded connection hangs — cannot occur on this pairing.
+- **`net.ipv4.ip_forward` is `1`** in the host netns the pod shares, and `/proc/sys` is `ro` there.
+  Both read directly from the pod.
+- **Toolbox gate** from an isolated worktree: **rc 3**, with `spec-immutability`, `decisions-log`,
+  `lint`, `l0`, `render-golden`, `l1` and `approval-policy` all **pass**; rc 3 is the two
+  environmental skips (`gitea-settings`, conformance L2/L3). **Not green. Reported as rc 3.**
+
+## What I did NOT verify
+
+- **That the tunnel now comes up.** This fix has not reconciled. The next reconcile is the test, and
+  its success criterion is specific: pods `1/1 Running`, and `wg show` reporting `interface: wg0`
+  with `listening port: 51820`.
+- **That the MASQUERADE and FORWARD rules actually apply.** They are the next statements after the
+  one that failed, so **they have never executed**. The backends matching (above) removes the worst
+  failure mode but proves nothing about the rules themselves. First check after the pods go Ready:
+  `iptables -t nat -S POSTROUTING | grep 10.90.0.0/24` on a node.
+- **Anything about client traffic.** Still zero peers enrolled, still no WAN port-forward, still no
+  off-LAN vantage point. The VPN has carried no packet.
+- **Whether the transient `REPLACE-ME` window has an upper bound.** It cleared within ~2 minutes
+  here; I did not determine the kubelet refresh behaviour, so a longer stall after a key change is
+  uncharacterised.
+- **The `sops set` hand-off command**, still. The operator filled the key in by their own route
+  (#62), so the exact quoting I documented inside `dev.sh run bash -c` remains unexercised.

infra/vpn-ingress/new-peer.sh

@@ -3,7 +3,7 @@
 # new-peer.sh — enrol one device on the remote-access VPN (platform/vpn-ingress).
 #
 # Generates a WireGuard keypair, renders the device's client profile, prints a QR code for a phone,
-# and prints the one `[Peer]` stanza to paste into platform/vpn-ingress/peers.yaml. The device's
+# and prints the one `[Peer]` stanza to paste into platform/vpn-ingress/peers.conf. The device's
 # private half is written to ONE 0600 file and nowhere else: not sent to the cluster, not committed,
 # never logged.
 #
@@ -62,7 +62,7 @@ set -euo pipefail
 die() { printf 'new-peer.sh: %s\n' "$*" >&2; exit 1; }
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
-PEERS_FILE="${REPO_ROOT}/platform/vpn-ingress/peers.yaml"
+PEERS_FILE="${REPO_ROOT}/platform/vpn-ingress/peers.conf"
 
 # --- defaults, each mirroring a value that is DECLARED elsewhere in this repo -------------------
 # These are duplicated here rather than parsed out of the YAML on purpose: this script is meant to
@@ -133,11 +133,22 @@ CLIENT_ADDR="${CLIENT_BASE}.${OCTET}"
 # --- refuse a collision, because the failure is otherwise invisible -----------------------------
 # Two devices sharing an address does not error anywhere: the server routes that address to
 # whichever peer handshook most recently, so BOTH devices appear to work intermittently.
-if [ -r "$PEERS_FILE" ] && grep -q "AllowedIPs *= *${CLIENT_ADDR}/32" "$PEERS_FILE"; then
-  die "${CLIENT_ADDR}/32 is already allocated in platform/vpn-ingress/peers.yaml. Pick another octet."
+# COMMENT LINES ARE NOT ALLOCATIONS. This used to grep the whole file and so matched the
+# COMMENTED-OUT EXAMPLE STANZA in the register, which made `.2` — the first address anyone would
+# ask for — permanently un-allocatable with a message claiming it was already taken. Strip
+# comments first: a real stanza's `AllowedIPs` line is never commented, while both the template
+# and every peer's `# <name> — <owner>` label are.
+# FAIL if the register is missing rather than skipping the check. The path was silently wrong once
+# (it still said peers.yaml after the file became peers.conf), and because the old guard was
+# `[ -r "$PEERS_FILE" ] && ...` the only symptom would have been duplicate detection quietly
+# never firing again — the exact silent-skip shape this repo treats as a defect.
+[ -r "$PEERS_FILE" ] || die "cannot read the peer register '$PEERS_FILE'.
+  Duplicate-address detection cannot run, so this script refuses to issue a profile."
+if grep -vE '^[[:space:]]*#' "$PEERS_FILE" | grep -q "AllowedIPs *= *${CLIENT_ADDR}/32"; then
+  die "${CLIENT_ADDR}/32 is already allocated in platform/vpn-ingress/peers.conf. Pick another octet."
 fi
-if [ -r "$PEERS_FILE" ] && grep -qi "^ *# *${NAME} " "$PEERS_FILE"; then
-  printf 'new-peer.sh: WARNING a peer comment already mentions "%s" in peers.yaml.\n' "$NAME" >&2
+if grep -qi "^ *# *${NAME} " "$PEERS_FILE"; then
+  printf 'new-peer.sh: WARNING a peer comment already mentions "%s" in peers.conf.\n' "$NAME" >&2
 fi
 
 # --- output location: 0700, and never inside the repo -------------------------------------------
@@ -204,7 +215,7 @@ cat <<EOF
   Profile     : ${PROFILE}   (0600; contains the private key)
 
   ------------------------------------------------------------------------------------------
-  STEP 1 — add this to platform/vpn-ingress/peers.yaml, under data.peers.conf, then PR it:
+  STEP 1 — append this to platform/vpn-ingress/peers.conf, then PR it:
 
     # ${NAME} — <owner>, enrolled $(date -u +%Y-%m-%d)
     [Peer]
@@ -223,7 +234,7 @@ cat <<EOF
   STEP 3 — delete the profile from this machine once the device has it:
     shred -u ${PROFILE} 2>/dev/null || rm -f ${PROFILE}
 
-  The tunnel will not work until the peers.yaml PR is MERGED and Flux has rolled the DaemonSet
+  The tunnel will not work until the peers.conf PR is MERGED and Flux has rolled the DaemonSet
   (~1 min). Until then the device handshakes and gets silence, exactly like an unknown key.
   ------------------------------------------------------------------------------------------
 EOF

platform/vpn-ingress/README.md

@@ -13,7 +13,7 @@ egress out the house WAN.
 | Transport | WireGuard, **udp/51820**, kernel implementation |
 | Where it runs | `hostNetwork` **DaemonSet** — one warm listener on every node |
 | Client subnet | `${WG_CLIENT_CIDR}` = `10.90.0.0/24`; `.1` is the server, `.2`–`.254` devices |
-| Authorisation | a device's **public key** is in [`peers.yaml`](./peers.yaml), or it cannot connect |
+| Authorisation | a device's **public key** is in [`peers.conf`](./peers.conf), or it cannot connect |
 | The one secret | the server's private key — **SOPS-encrypted in this tree**, `wg-server-key.sops.yaml` |
 | Exposure | one hand-made WAN port-forward on the SOHO router, off-repo |
 | Enrolling a device | [`infra/vpn-ingress/new-peer.sh`](../../infra/vpn-ingress/new-peer.sh) |
@@ -129,7 +129,7 @@ translations win here.
 
 | half | where | why |
 |---|---|---|
-| peer **public** keys + addresses | [`peers.yaml`](./peers.yaml), **plaintext in git** | a public key grants nothing by itself, and this makes *"who can get into my house"* a reviewable PR diff with `git log` as its audit trail |
+| peer **public** keys + addresses | [`peers.conf`](./peers.conf), **plaintext in git**, as a content-hashed `configMapGenerator` so an edit rolls the pods | a public key grants nothing by itself, and this makes *"who can get into my house"* a reviewable PR diff with `git log` as its audit trail |
 | the server's **private** key | `wg-server-key.sops.yaml`, **SOPS-encrypted in git** | the only real secret (R-SEC-01, spec docs/07). Ships with a `REPLACE-ME` placeholder: an agent must not mint a long-lived private key (CLAUDE.md §6), so the operator `sops set`s it in |
 
 The two are joined only at pod start, by the init container, into a **`medium: Memory` emptyDir** —
@@ -166,13 +166,26 @@ NetworkPolicy applies.
 ## Operating it
 
 * **Enrol a device:** `./infra/vpn-ingress/new-peer.sh <name> <octet>` → paste the printed `[Peer]`
-  stanza into `peers.yaml` → PR → merge. Phones scan a QR code; desktops import a `.conf`.
-* **Revoke a device:** delete its stanza → PR → merge. No other step; the key stops working.
+  stanza into `peers.conf` → PR → merge. Phones scan a QR code; desktops import a `.conf`.
+* **Revoke a device:** delete its stanza from `peers.conf` → PR → merge. No other step; the key
+  stops working as soon as the pods roll (the generator's content hash guarantees they do).
 * **Is it up?** `kubectl --context k3s-prod -n vpn-ingress get ds wireguard` — three Ready.
 * **Who is connected?** `kubectl --context k3s-prod -n vpn-ingress exec ds/wireguard -- wg show`
   (`latest handshake` under ~3 min means live). Never dump `wg showconf` — it prints the private key.
 * **Full bring-up and verification:** `runbooks/vpn-remote-access.md`.
 
+## Measured on prod, 2026-10-06 — what is now known rather than assumed
+
+The first real reconcile settled four things this component's design rested on. Three went the
+right way; one was a defect in my own manifest.
+
+| question | answer |
+|---|---|
+| Does the **kernel module** reach the pod? | **Yes.** `ip link add dev wg0 type wireguard` succeeds, and `/proc/modules` lists `wireguard`, after the `node_baseline` run. `CAP_SYS_MODULE` is correctly not needed. |
+| Does `allowPrivilegeEscalation: false` break the image's **s6 init**? | **No.** The container reaches `wg-quick` normally. The flag stays. |
+| Is the image's **iptables** backend compatible with the host's? | **Yes — both nft.** The image ships `iptables v1.8.13 (nf_tables)` via `xtables-nft-multi`, and Debian 13 is nf_tables. This was the documented worst fear (rules silently landing in a table the kernel does not consult); it is closed. |
+| Can the pod set **`net.ipv4.ip_forward`**? | **No, and it must not try.** `/proc/sys` is mounted **read-only** under `hostNetwork` (`proc /proc/sys proc ro,…`), because those are the host's globals; `sysctl -w` fails with EPERM whatever the capabilities. A failed `PostUp` is fatal to `wg-quick`, so this one line took the whole tunnel down. The node already has it set to `1`; the init container now **verifies** rather than writes. |
+
 ## Prerequisites outside this directory
 
 1. **The `wireguard` kernel module on every node.** Added to `node_baseline_kernel_modules`
@@ -199,7 +212,7 @@ NetworkPolicy applies.
   covered generically by `KubeDeploymentReplicasMismatch`/`KubePodNotReady` from
   kube-prometheus-stack. **This is the top follow-up.**
 * **No preshared keys.** They would add a symmetric post-quantum hedge on top of the Noise
-  handshake — and would be a real secret, forcing `peers.yaml` into SOPS and costing the
+  handshake — and would be a real secret, forcing `peers.conf` into SOPS and costing the
   reviewability above. Revisit only if the threat model changes; if it does, the PSK belongs in the
   `wg-server-key` Secret.
 * **No IPv6.** The server offers no IPv6 tunnel address, so a full-tunnel client with native IPv6

platform/vpn-ingress/daemonset.yaml

@@ -37,6 +37,10 @@
 #     /etc/sysctl.d/99-k3s-cilium.conf), so no pod sysctl is needed — and `net.ipv4.ip_forward`
 #     is NOT in the kubelet's safe-sysctl allowlist, so a pod-netns version of this would have
 #     required `--allowed-unsafe-sysctls` on all three kubelets (a node-restart change).
+#     COROLLARY LEARNED THE HARD WAY (prod, 2026-10-06): this pod must not merely avoid NEEDING
+#     the sysctl, it must not ATTEMPT it. hostNetwork implies /proc/sys is mounted read-only, so
+#     `sysctl -w` fails with EPERM regardless of capabilities, and wg-quick treats a failed PostUp
+#     as fatal and deletes the interface. Verify the value; never write it.
 #   * no LoadBalancer VIP, so no CiliumL2AnnouncementPolicy lease lottery (the defect that cost
 #     this LAN an 8-day Minecraft outage) and no `externalTrafficPolicy` trade-off at all.
 #   * no double encapsulation. WireGuard's UDP lands on the node's own NIC, so the underlay is a
@@ -104,7 +108,7 @@ spec:
       dnsPolicy: ClusterFirstWithHostNet
       automountServiceAccountToken: false
       # ── Assemble the running config: PUBLIC peer register (git) + PRIVATE server key (Secret) ──
-      # The two halves are deliberately stored apart (peers.yaml explains why) and are only ever
+      # The two halves are deliberately stored apart (peers.conf explains why) and are only ever
       # joined here, at pod start, into a tmpfs that is destroyed with the pod. The server's private
       # key is therefore never written to any node's disk, never committed, and never logged.
       initContainers:
@@ -171,6 +175,19 @@ spec:
                 exit 1
               fi
 
+              # The pod shares the HOST netns, so this reads the node's real setting. Reading
+              # /proc/sys is permitted even though writing is not (see the PostUp note below).
+              # Fail closed: a tunnel that comes up but cannot forward would look healthy to every
+              # probe here and simply drop every client's traffic.
+              if ! grep -qx 1 /proc/sys/net/ipv4/ip_forward; then
+                echo "FATAL: net.ipv4.ip_forward is 0 on this node, so forwarded VPN traffic would" >&2
+                echo "       be dropped. This pod CANNOT set it: with hostNetwork the runtime mounts" >&2
+                echo "       /proc/sys read-only, because it is the host's global setting." >&2
+                echo "       Fix on the NODE: run the node_baseline role (it writes" >&2
+                echo "       /etc/sysctl.d/99-k3s-cilium.conf) — runbooks/vpn-remote-access.md step 1." >&2
+                exit 1
+              fi
+
               {
                 echo '[Interface]'
                 echo "Address = $base.1/$mask"
@@ -184,9 +201,20 @@ spec:
                 echo 'MTU = 1420'
                 printf 'PrivateKey = %s\n' "$key"
                 # ── Forwarding + SNAT, applied in the HOST netns when wg0 comes up ──
-                # ip_forward is already 1 from node_baseline; re-asserted so this component does not
-                # silently depend on another role's sysctl file surviving.
-                echo 'PostUp = sysctl -q -w net.ipv4.ip_forward=1'
+                # NO `sysctl -w net.ipv4.ip_forward=1` HERE. It is IMPOSSIBLE from this pod and it was
+                # the only thing stopping the tunnel coming up — MEASURED on prod 2026-10-06:
+                #     [#] sysctl -q -w net.ipv4.ip_forward=1
+                #     sysctl: permission denied on key "net.ipv4.ip_forward"
+                #     [#] ip link delete dev wg0
+                # and wg-quick then tore the whole tunnel down. The cause is not a missing
+                # capability: with `hostNetwork: true` the runtime mounts /proc/sys READ-ONLY in the
+                # container (confirmed in /proc/mounts: `proc /proc/sys proc ro,...`), precisely
+                # because those sysctls are the HOST's globals and a container must not rewrite
+                # them. CAP_NET_ADMIN does not and cannot lift a read-only mount.
+                # It was never needed anyway: node_baseline writes net.ipv4.ip_forward=1 to
+                # /etc/sysctl.d/99-k3s-cilium.conf, and reading it from this pod returns 1. The
+                # init container now VERIFIES that (a read, which /proc/sys does allow) and fails
+                # closed with a pointed message, which is what the write was pretending to achieve.
                 # SNAT client traffic to the node's address. REQUIRED: without it a LAN host would
                 # reply to 10.90.0.x, find no route, hand the packet to the router, and the router
                 # would drop it — so every connection would hang rather than fail. Matching on
@@ -246,8 +274,10 @@ spec:
             # `kubectl get pod -o wide` shows what this listener owns.
             - { name: wireguard, containerPort: 51820, hostPort: 51820, protocol: UDP }
           securityContext:
-            # NET_ADMIN is the whole privilege budget: create the wg0 link, set the host sysctl, and
-            # write the two netfilter rules above. Everything else is dropped, and the container is
+            # NET_ADMIN is the whole privilege budget: create the wg0 link and write the netfilter
+            # rules above. (It does NOT let the pod set a host sysctl — /proc/sys is read-only under
+            # hostNetwork — which is why nothing here tries.) Everything else is dropped, and the
+            # container is
             # NOT privileged — which also keeps it clear of restrict-host-namespaces' second rule.
             # SYS_MODULE is deliberately NOT granted: the `wireguard` module is loaded by the node
             # (infra/ansible/roles/node_baseline, node_baseline_kernel_modules), so this container
@@ -261,6 +291,16 @@ spec:
                 - NET_ADMIN
             # readOnlyRootFilesystem intentionally UNSET: the image's s6 init writes under /run and
             # /var during startup. Same deferral as crafty/headlamp.
+            #
+            # EXPECTED, HARMLESS STARTUP NOISE — do not "fix" it. Because capabilities are dropped
+            # to NET_ADMIN only, the image's s6 init cannot chown /config (no CAP_CHOWN) and logs a
+            # run of `chown: ... Operation not permitted` plus "Permissions could not be set. This
+            # is probably because your volume mounts are remote or read-only" and a scary "we will
+            # not provide support for it". It is wrong about the cause and it does not matter:
+            # /config is a writable tmpfs emptyDir, everything here runs as root (uid 0) anyway, and
+            # wg-quick proceeds normally — verified on prod 2026-10-06, where the tunnel's only
+            # failure was the sysctl above, well past these warnings. Granting CAP_CHOWN to silence
+            # log noise would widen the privilege set of an internet-facing pod for nothing.
           resources:
             requests:
               cpu: 25m

platform/vpn-ingress/kustomization.yaml

@@ -11,10 +11,16 @@
 # NOT in platform/kustomization.yaml — see clusters/base/vpn-ingress.yaml.
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
+# REQUIRED for the configMapGenerator below to be wired up at all, not merely tidy. A generated
+# ConfigMap inherits NO namespace, every other object here declares `vpn-ingress`, and kustomize's
+# nameReference transformer will not rewrite a reference across a namespace boundary — so without
+# this the DaemonSet keeps mounting the unhashed name `wg-peers`, which does not exist, and the
+# pods wedge on a missing volume. Verified by building it both ways (kustomize v5.8.1).
+# Same placement as runbooks/kustomization.yaml, which uses `namespace: runbooks` for its own
+# content generator.
+namespace: vpn-ingress
 resources:
   - namespace.yaml
-  # The peer register: which devices may dial in. PLAINTEXT and reviewable on purpose (see the file).
-  - peers.yaml
   # The listener itself: hostNetwork DaemonSet, udp/51820 on every node.
   - daemonset.yaml
   # Namespace default-deny baseline. NOTE: does NOT constrain the hostNetwork DaemonSet — the file
@@ -38,3 +44,26 @@ resources:
 # hands Flux the raw ciphertext, the Secret APPLIES CLEANLY full of ENC[...], and nothing in any
 # Flux condition looks wrong. The init container's `wg pubkey` guard exists partly to turn exactly
 # that into a named error rather than a silently non-working tunnel.
+
+# ── THE PEER REGISTER, as a CONTENT-HASHED ConfigMap ─────────────────────────────────────────
+# peers.conf (plaintext, reviewable — see the file) becomes the `wg-peers` ConfigMap. It is a
+# GENERATOR, not a plain resource, and that distinction is load-bearing rather than stylistic:
+# kustomize appends a hash of the content to the generated name and rewrites the DaemonSet's
+# volume reference to match, so adding or revoking a peer changes the pod template and ROLLS THE
+# PODS automatically.
+#
+# A fixed-name ConfigMap (which is what this component shipped first) does not do that. Flux
+# updates it in place, the pod template is byte-identical, no rollout is triggered — and because
+# the init container assembles wg0.conf ONCE at pod start into a tmpfs, the running tunnel keeps
+# the old peer list indefinitely. Measured on prod 2026-10-06: a merged peer reached the
+# ConfigMap while `wg show` listed no peers and the DaemonSet still read generation=1, having
+# never rolled. The runbook's "PR -> merge -> Flux rolls the DaemonSet" was false until this.
+#
+# DO NOT set `disableNameSuffixHash` here. The hash IS the mechanism.
+configMapGenerator:
+  - name: wg-peers
+    files:
+      - peers.conf
+    options:
+      labels:
+        app.kubernetes.io/name: vpn-ingress

platform/vpn-ingress/networkpolicy.yaml

@@ -19,7 +19,7 @@
 # protects this port, and it would be enforcing nothing. So there isn't one.
 #
 # WHAT ACTUALLY PROTECTS THE EXPOSED PORT, then, since the CNI does not:
-#   1. WireGuard's cryptographic peer authentication. A packet whose key is not in peers.yaml gets
+#   1. WireGuard's cryptographic peer authentication. A packet whose key is not in peers.conf gets
 #      NO REPLY — see README "Why this is safe to expose". This is the real control.
 #   2. The SOHO router's forward: only udp/51820 is forwarded inbound, to one node.
 #   3. The blast radius once authenticated is deliberately the whole LAN — that IS the requirement

platform/vpn-ingress/peers.conf

@@ -1,4 +1,16 @@
----
+# THIS FILE IS THE MOUNTED CONTENT. It is turned into the `wg-peers` ConfigMap by
+# `configMapGenerator` in kustomization.yaml, whose generated name carries a CONTENT HASH — so
+# editing this file changes the ConfigMap name, which changes the DaemonSet's pod template, which
+# ROLLS THE PODS. That is the whole reason it is a generator and not an inline ConfigMap manifest:
+# a fixed-name ConfigMap updates in place, the pod template never changes, no rollout happens, and
+# the init container's wg0.conf (built once at pod start, in tmpfs) keeps the OLD peer list
+# forever. Measured 2026-10-06: a merged peer sat in the ConfigMap while `wg show` listed none and
+# the DaemonSet reported generation=1 — it had never rolled. Same mechanism and same fix as
+# runbooks/kustomization.yaml.
+#
+# Every line here is WireGuard config. `#` is a legal comment in it, so the documentation below
+# travels inside the file that is actually mounted, rather than in a wrapper that gets stripped.
+#
 # ============================================================================================
 # THE PEER REGISTER — every device allowed to dial in, in PLAINTEXT, in git, on purpose.
 # ============================================================================================
@@ -41,33 +53,40 @@
 # the Noise handshake and would be a genuine secret — which would force this register into SOPS
 # and cost the reviewability above. Revisit only if the threat model changes; if it does, the PSK
 # belongs in the `wg-server-key` Secret, not here. See README "Hardening not taken".
-apiVersion: v1
-kind: ConfigMap
-metadata:
-  name: wg-peers
-  namespace: vpn-ingress
-  labels:
-    app.kubernetes.io/name: vpn-ingress
-data:
-  # Appended VERBATIM to the generated [Interface] block, in this order, at pod start.
-  #
-  # *** THERE ARE NO PEERS YET. THAT IS THE CORRECT INITIAL STATE, NOT AN OVERSIGHT. ***
-  # An agent must not mint key material (CLAUDE.md §6), so no device could be enrolled as part of
-  # authoring this component. A zero-peer WireGuard interface is valid and starts cleanly: the
-  # DaemonSet will run and listen, and every handshake will be refused because no key is trusted.
-  # The VPN is therefore INERT-BUT-HEALTHY until the first stanza lands — fail-closed, and visible
-  # (`wg show` reports an interface with no peers).
-  #
-  # COPY THIS TEMPLATE, uncomment, one block per device:
-  #
-  #   # pixel-8 — Keith's phone, enrolled 2026-10-05
-  #   [Peer]
-  #   PublicKey = <the public key new-peer.sh printed>
-  #   AllowedIPs = 10.90.0.2/32
-  #
-  # Keep the `# <name> — <owner>, enrolled <date>` comment line. It is the only place a key is
-  # tied to a human-recognisable device; `wg show` can only ever print the key itself, so without
-  # it an incident responder cannot tell which stanza to delete.
-  peers.conf: |
-    # No peers enrolled yet. See the template in this file's comments and
-    # ./infra/vpn-ingress/new-peer.sh. One [Peer] block per device.
+#
+# name: wg-peers
+# namespace: vpn-ingress
+# labels:
+# app.kubernetes.io/name: vpn-ingress
+# Appended VERBATIM to the generated [Interface] block, in this order, at pod start.
+#
+# *** THERE ARE NO PEERS YET. THAT IS THE CORRECT INITIAL STATE, NOT AN OVERSIGHT. ***
+# An agent must not mint key material (CLAUDE.md §6), so no device could be enrolled as part of
+# authoring this component. A zero-peer WireGuard interface is valid and starts cleanly: the
+# DaemonSet will run and listen, and every handshake will be refused because no key is trusted.
+# The VPN is therefore INERT-BUT-HEALTHY until the first stanza lands — fail-closed, and visible
+# (`wg show` reports an interface with no peers).
+#
+# COPY THIS TEMPLATE, uncomment, one block per device:
+#
+#   # <device-name> — <owner>, enrolled <YYYY-MM-DD>
+#   [Peer]
+#   PublicKey = <the public key new-peer.sh printed>
+#   AllowedIPs = 10.90.0.<octet>/32
+#
+# The placeholders above are deliberately NOT valid values. An earlier version of this template
+# used a real-looking `10.90.0.2/32`, and new-peer.sh's duplicate-address check — which grepped
+# the whole file — matched it, so `.2` could never be allocated and the script insisted it was
+# already taken. The check now ignores comments; keeping the example unmatchable too means a
+# future grep cannot be fooled either.
+#
+# Keep the `# <name> — <owner>, enrolled <date>` comment line. It is the only place a key is
+# tied to a human-recognisable device; `wg show` can only ever print the key itself, so without
+# it an incident responder cannot tell which stanza to delete.
+#
+# No peers enrolled yet. See the template in this file's comments and
+# ./infra/vpn-ingress/new-peer.sh. One [Peer] block per device.
+# keith-phone — <owner>, enrolled 2026-10-06
+[Peer]
+PublicKey = pBRSHrRyG2hnsuZ6FvHfEzF8hOVTF5stHUb/7fW2Km8=
+AllowedIPs = 10.90.0.2/32

platform/vpn-ingress/wg-server-key.sops.yaml.example

@@ -5,7 +5,7 @@
 # WHAT THIS IS: the WireGuard SERVER's long-term private key for the remote-access VPN
 # (platform/vpn-ingress). It is the ONE secret in the whole component. The init container in
 # daemonset.yaml reads it at `/run/wg-server-key/privatekey` and joins it to the PLAINTEXT peer
-# register (peers.yaml) in a tmpfs, so the assembled wg0.conf never touches a node's disk.
+# register (peers.conf) in a tmpfs, so the assembled wg0.conf never touches a node's disk.
 #
 # WHY IT IS IN GIT, SOPS-ENCRYPTED, AND NOT HAND-CREATED. R-SEC-01 / spec docs/07: secrets live in
 # source, encrypted, and reach the cluster only through Flux. An out-of-band `kubectl create secret`

runbooks/vpn-remote-access.md

@@ -21,7 +21,7 @@ behaves like a machine on the LAN: full reach to `192.168.2.0/24`, the Gateway's
 DNS, and internet egress out the house WAN.
 
 Authorisation is one thing only: the device's **public key is in
-`platform/vpn-ingress/peers.yaml`**. An unlisted key gets no reply at all.
+`platform/vpn-ingress/peers.conf`**. An unlisted key gets no reply at all.
 
 > **An enrolled device is as privileged as a machine sitting in the house** — including the three
 > k3s nodes (`192.168.2.10/.11/.12`: apiserver 6443, kubelet 10250, SSH 22). That is what "reach
@@ -134,6 +134,37 @@ specific failure in its log — so you never get a server that silently cannot c
 | `It is EMPTY` | the value was blanked |
 | `still SOPS CIPHERTEXT (starts with ENC[)` | the Secret reached the cluster undecrypted — this environment's overlay is missing its `vpn-ingress` decryption patch. **This is the dangerous one:** the Secret applies cleanly and every Flux condition stays green |
 | `wg pubkey rejected it` with none of the above | a mangled value, or a *public* key pasted by mistake |
+| `net.ipv4.ip_forward is 0 on this node` | the node_baseline role has not run here (step 1). The pod **cannot** set this itself — under `hostNetwork` the runtime mounts `/proc/sys` read-only, because it is the host's global setting |
+| `0 peer(s)` after you merged a peer | the DaemonSet did not roll. Check its `generation` (above). Pre-2026-10-06 this was guaranteed, because the register was a fixed-name ConfigMap; if it recurs, something has reverted `peers.conf` to a plain resource instead of a `configMapGenerator` |
+
+### What a healthy start looks like
+
+Measured on prod 2026-10-06. The init container logs one line, naming the shape and never the key:
+
+```
+wg0.conf assembled: 0 peer(s), server 10.90.0.1/24, udp/51820.
+```
+
+then the `wireguard` container brings the tunnel up:
+
+```
+**** Found WG conf /config/wg_confs/wg0.conf, adding to list ****
+**** Activating tunnel /config/wg_confs/wg0.conf ****
+[#] ip link add dev wg0 type wireguard
+[#] wg addconf wg0 /dev/fd/63
+[#] ip -4 address add 10.90.0.1/24 dev wg0
+[#] ip link set mtu 1420 up dev wg0
+```
+
+**Ignore the `chown: ... Operation not permitted` run before that**, and the image's own
+"Permissions could not be set ... we will not provide support for it". Capabilities are dropped to
+`NET_ADMIN` only, so its s6 init has no `CAP_CHOWN`; `/config` is a writable tmpfs, everything runs
+as root, and `wg-quick` proceeds. It is wrong about the cause and it does not matter.
+
+**A pod stuck `0/1 Running` with `Startup probe failed: Unable to access interface: No such device`
+means `wg-quick` tore the tunnel down** — read the `wireguard` container log for the `[#]` line it
+died on. That is the shape of a real failure; the probe is doing its job of refusing to call a
+server without a `wg0` "ready".
 
 ## Step 3 — forward udp/51820 on the router (once)
 
@@ -188,10 +219,23 @@ It generates the device's keypair, writes a `0600` client profile, prints a QR c
 
 Then:
 
-1. Paste the stanza into `platform/vpn-ingress/peers.yaml` under `data.peers.conf`, keeping the
+1. Append the stanza to `platform/vpn-ingress/peers.conf`, keeping the
    `# <name> — <owner>, enrolled <date>` comment. `wg show` can only ever print the key, so that
    comment is the only record of which stanza belongs to which device.
-2. PR → merge. Flux rolls the DaemonSet (~1 min).
+2. PR → merge. Flux rolls the DaemonSet (~1 min), because `peers.conf` is a
+   **content-hashed** `configMapGenerator`: editing it changes the ConfigMap's generated name,
+   which changes the pod template, which forces the roll. (It did **not** work this way at first —
+   a fixed-name ConfigMap updates in place, the pod template never changes, and the init container
+   keeps the old peer list forever. Measured on prod 2026-10-06.) Confirm it actually rolled:
+
+   ```bash
+   ./infra/devcontainer/dev.sh run bash -c \
+     'kubectl --context k3s-prod -n vpn-ingress get ds wireguard \
+        -o jsonpath="{.metadata.generation}{\"/\"}{.status.observedGeneration}{\"\n\"}"'
+   ```
+
+   The generation must have **increased** since before the merge. If it is still `1`, the roll did
+   not happen and `wg show` will list no peer no matter how long you wait.
 3. Get the profile onto the device (QR scan for phones; "Import tunnel from file" on
    Windows/macOS; `/etc/wireguard/<name>.conf` + `wg-quick@<name>` on Linux).
 4. **Delete the profile from your machine**: `shred -u <path>`. It is the only copy of that
@@ -231,7 +275,7 @@ if the router is not delivering the packets, and a `handshake` with no completed
 
 ## Revoking a device
 
-Delete its `[Peer]` stanza from `peers.yaml`, PR, merge. Nothing else — the key stops working on the
+Delete its `[Peer]` stanza from `peers.conf`, PR, merge. Nothing else — the key stops working on the
 next reconcile. **Never re-use that address octet**: an old profile would silently start working
 again as a different device.