feat(bulwark): new chart for Bulwark Webmail (1.0.0+up1.12.0)

A JMAP webmail client for the stalwart chart (Gitea #65): StatefulSet, one PVC
at /app/data, Service plus headless Service, Ingress at a host root, two
OnePasswordItems, three probes, computed limits, replicas plus scaleDown, strict
values.schema.json.

Everything below was measured against the source at tag 1.12.0 rather than read
out of the documentation, which was wrong about three of them.

THE DEFINING PROPERTY: THE VOLUME BEATS THE CHART, FOR EVERY VALUE, SILENTLY.
configManager.get resolves "admin override > env var > default", the admin
dashboard may write any key of CONFIG_ENV_MAP, and nothing reports that it just
disconnected the chart - so a helm upgrade can succeed and change nothing.
Upstream documents this for the server URL only; it is true of everything.
Exactly three values escape it (SESSION_SECRET(_FILE), ADMIN_PASSWORD,
BULWARK_TELEMETRY). The value that closes it, bulwark.adminConfigReadOnly,
defaults to false because its price is threefold: it freezes the settings policy
(and with it the only way to move Web Push off the vendor relay), it freezes an
override that ALREADY exists instead of removing it, and on a fresh install it
stops admin.json from being written at all - so the admin dashboard never comes
up and its login answers HTTP 500 while the pod stays Ready.

OIDC-only sign-in, with the real way back out of a lockout: not helm upgrade
with OAUTH_ONLY=false (oauthOnly goes through the same precedence chain) but
removing the override in the admin dashboard. That is why ADMIN_PASSWORD is set
- the dashboard is the door. It generates no random password and logs nothing,
so the #65 analogy does not apply.

SESSION_SECRET_FILE and OAUTH_CLIENT_SECRET_FILE are both used - the better path
garage (#81) and keycloak (#83) did not have - in one projected volume mounted
WITHOUT subPath, because both are re-read on every use and a subPath mount is
never refreshed, and at mode 0440 because secret files are owned by root and
fsGroup only supplies the group.

Two backup statements, both at the value: without the session secret the
synchronized settings are unreadable out of an intact volume, and if the
dashboard's OAuth setup was ever used the client secret sits in config.json on
that volume in cleartext.

Probes: all three a plain GET on /api/health, with the limit written at the
readiness value - it carries process, HTTP acceptance, a free event loop and
Next.js routing, and nothing about the reported state or about Stalwart.

No ConfigMap, so the checksum/config rule (#82) has nothing to attach to, and
values.yaml says so explicitly; the op:// paths are covered by
checksum/secret-ref.

Renovate: no versioningTemplate, measured rather than assumed. 315 tags in eight
shapes (releases, a second v-prefixed family of the same images, an -always
flavour, floating minors and names, commit SHAs, betas, attestations) and plain
docker versioning excludes all six unwanted ones. Dry runs at 1.12.0, 1.11.0 and
1.10.0 are recorded in the block.

Part of #89 - deliberately not "Fixes", because one binding decision of the
issue was changed out of necessity and wants ratification rather than an
automatic close: the plan specifies HEAD /api/health for all three probes, and a
Kubernetes probe cannot send HEAD at all (HTTPGetAction has no method field; the
kubelet always issues GET). The alternative, an exec probe, would mean starting a
Node process every few seconds in an image that carries no curl and no wget. GET
is used instead and is marginally more capable than HEAD, so every limit the
issue argues is unchanged - but the decision is the maintainer's to confirm.

README.md

@@ -16,6 +16,7 @@ Every chart has a wiki page of its own — `https://git.jk-dev.de/jlab-cluster/h
 |---|---|---|
 | `apache-tika` | Apache Tika | Deployment + Service only (no ingress) |
 | `bentopdf` | BentoPDF | Stateless Deployment + `config.json` ConfigMap, `subPath`-mounted into the web root and always rendered (empty renders as `{}`) |
+| `bulwark` | Bulwark Webmail (JMAP client for Stalwart) | **The companion to `stalwart`, and a pure client**: no mail, no database, no cache, no broker — the messages belong to the Stalwart release named by `bulwark.jmapServerUrl`. StatefulSet with **one** PVC at `/app/data`, carrying all four of Bulwark's directories (admin config, admin state with the audit log, encrypted user settings, telemetry) as subdirectories — one volume because snapshots are atomic per volume and never across them (the `garage` lesson, #81). No ConfigMap, so no `checksum/config` (§9 has nothing to attach to); the `op://` paths are covered by `checksum/secret-ref`. **The defining property, and it governs every value: the VOLUME BEATS THE CHART.** `configManager.get` resolves `admin override > env var > default`, the admin dashboard may write *any* key, and nothing says it just disconnected the chart — so a `helm upgrade` with a changed value can succeed and change nothing. Upstream documents this only for the server URL; it is true of everything. Exactly three values escape it (`SESSION_SECRET(_FILE)`, `ADMIN_PASSWORD`, `BULWARK_TELEMETRY`), and `bulwark.adminConfigReadOnly` closes it at a price that is **threefold and measured**: it freezes the settings policy (and with it the only way to move Web Push off the vendor relay), it freezes an override that *already* exists rather than removing it, and on a **fresh** install it stops `admin.json` from being written at all — so the admin dashboard never comes up and answers HTTP 500 while the pod stays Ready. Hence the default `false`. Sign-in is **OIDC-only** (`oauth.only`), and the way back out of a lockout is **not** `helm upgrade` with it `false` — `oauthOnly` is read through the same precedence chain, so the repair is removing the override in the **admin dashboard**, which is why `ADMIN_PASSWORD` is set at all (it generates no random password and logs nothing — the `#65` analogy does not hold here). Its **redirect URI carries the UI language** (`/<locale>/auth/callback`, 27 locales, and the language is not in the visible URL), so a single registered URI is the likeliest cause of a failed first sign-in. Both `SESSION_SECRET_FILE` and `OAUTH_CLIENT_SECRET_FILE` exist and are used — the better path `garage` and `keycloak` did not have — mounted **without `subPath`** so that a rotation takes effect without a restart, since both are re-read on every use. Two backup statements, both sharp: without the session secret the synchronized settings are unreadable **out of an intact volume**, and if the dashboard's OAuth setup was ever used the client secret sits in `config.json` on that volume in **cleartext**. All three probes are a plain GET on `/api/health` — **not** HEAD, which a `HTTPGetAction` cannot send — and the limit is written at the value: it carries process, HTTP acceptance, a free event loop and Next.js routing, and **nothing** about Stalwart, so with the mail server gone the pod is green. Served only at a host **root** (`NEXT_PUBLIC_BASE_PATH` is compiled in), one replica (single RWO PVC), two emptyDirs for `readOnlyRootFilesystem` (`/tmp`, `/app/.next/cache` — image optimization is active because `images.unoptimized` is in the lite branch only) |
 | `calibre-web-automated` | Calibre-Web Automated | StatefulSet, extra consume-PVC |
 | `cyberchef` | CyberChef | Stateless Deployment |
 | `freesailarr` | gluetun VPN media stack (qbittorrent, prowlarr, flaresolverr, radarr, recyclarr, sonarr, seerr, bazarr, and mediathekarr off by default) | Single-pod StatefulSet: all apps share gluetun's network namespace; config volumes via volumeClaimTemplates, media PVCs as existingClaims (optional per-category `subPath`, so one claim can serve all three categories). One ClusterIP Service per app (mediathekarr's carries both of its ports); no global `ingress.domain`. Ingress in two shapes that mix: one host per app (default, each app's host required), or one shared `ingress.host` with the apps as sub-paths (documented ingress exception below) |
@@ -34,7 +35,7 @@ Every chart has a wiki page of its own — `https://git.jk-dev.de/jlab-cluster/h
 | `samba` | Samba | StatefulSet, users secret + config ConfigMap |
 | `satisfactory` | Satisfactory game server | StatefulSet, no ingress |
 | `searxng` | SearXNG | Stateless Deployment + settings ConfigMap (`use_default_settings: true` plus a free-form `settings.extra` passthrough); the signing key is a required `OnePasswordItem`, an external Valkey an optional second one. `ingress.domain` is read twice — Ingress host and `SEARXNG_BASE_URL` — so it stays required with the Ingress switched off |
-| `stalwart` | Stalwart mail server (SMTP, IMAP, POP3, JMAP, ManageSieve) | **The chart configures almost nothing, and that is the chart's defining property.** Since v0.16 Stalwart keeps its whole configuration — every listener, the blob store, the in-memory store, TLS objects, domains and the cluster roles — inside the data store and manages it over JMAP; the only file on disk is a `config.json` that names the data store and nothing else. So the chart renders that ConfigMap (secret-free: `authSecret` uses the `EnvironmentVariable` variant, so the password arrives by `secretKeyRef` and `checksum/config` stays meaningful), one StatefulSet per entry of the `nodes` **map** with `STALWART_ROLE` and `STALWART_HOSTNAME`, one NodePort Service **per port** (not per group — a NodePort is cluster-unique, so `full` and `mx` can only take SMTP behind the same Service, selected by a per-port pod label), a per-group ClusterIP `http` Service for the Ingress, per-group headless Services and NetworkPolicies, and a cert-manager `Certificate` for the mail ports. Everything else is operator work in the WebUI, which is why `NOTES.txt` carries an eight-step first install. Four traps worth knowing before reading the chart: **the role lookup fails open** — a node whose `ClusterRole` is missing from the database enables every listener *and* every task while staying Running with a green probe, so `mx` ships at `replicas: 0` and the NetworkPolicy is a ceiling independent of what was bound; **`NET_BIND_SERVICE` is a documented deviation needed to `exec`, not to bind** (the image sets `setcap cap_net_bind_service=+ep`, so `drop: [ALL]` alone makes the kernel fail `execve` — removing it as "unused" stops the chart starting); **`externalTrafficPolicy` must be `Cluster`** (no pod runs on a control-plane node while the HA proxy delivers to them, so `Local` would drop every packet) and the source address it costs is restored only by the HA proxy's PROXY v2 header; and **`/healthz` is rate-limited to 100 req/60s per source IP**, which is a node IP for kubelet probes, so the probe intervals are calculated rather than chosen. A first install needs `bootstrap.enabled: true` because the setup wizard appears only when `config.json` is *absent*. Optional `valkey` subchart — **this repo's own chart, from the published index**, off by default and gated on `valkeySubchart.enabled` (not `valkey.enabled`, which the subchart's strict schema rejects); never change `valkey/` and this chart in the same PR, see "Chart dependencies" |
+| `stalwart` | Stalwart mail server (SMTP, IMAP, POP3, JMAP, ManageSieve) | A webmail client for it is the separate `bulwark` chart (above), pointed at this release's JMAP endpoint — the two are only useful together, and nothing in either reports the other being away. **The chart configures almost nothing, and that is the chart's defining property.** Since v0.16 Stalwart keeps its whole configuration — every listener, the blob store, the in-memory store, TLS objects, domains and the cluster roles — inside the data store and manages it over JMAP; the only file on disk is a `config.json` that names the data store and nothing else. So the chart renders that ConfigMap (secret-free: `authSecret` uses the `EnvironmentVariable` variant, so the password arrives by `secretKeyRef` and `checksum/config` stays meaningful), one StatefulSet per entry of the `nodes` **map** with `STALWART_ROLE` and `STALWART_HOSTNAME`, one NodePort Service **per port** (not per group — a NodePort is cluster-unique, so `full` and `mx` can only take SMTP behind the same Service, selected by a per-port pod label), a per-group ClusterIP `http` Service for the Ingress, per-group headless Services and NetworkPolicies, and a cert-manager `Certificate` for the mail ports. Everything else is operator work in the WebUI, which is why `NOTES.txt` carries an eight-step first install. Four traps worth knowing before reading the chart: **the role lookup fails open** — a node whose `ClusterRole` is missing from the database enables every listener *and* every task while staying Running with a green probe, so `mx` ships at `replicas: 0` and the NetworkPolicy is a ceiling independent of what was bound; **`NET_BIND_SERVICE` is a documented deviation needed to `exec`, not to bind** (the image sets `setcap cap_net_bind_service=+ep`, so `drop: [ALL]` alone makes the kernel fail `execve` — removing it as "unused" stops the chart starting); **`externalTrafficPolicy` must be `Cluster`** (no pod runs on a control-plane node while the HA proxy delivers to them, so `Local` would drop every packet) and the source address it costs is restored only by the HA proxy's PROXY v2 header; and **`/healthz` is rate-limited to 100 req/60s per source IP**, which is a node IP for kubelet probes, so the probe intervals are calculated rather than chosen. A first install needs `bootstrap.enabled: true` because the setup wizard appears only when `config.json` is *absent*. Optional `valkey` subchart — **this repo's own chart, from the published index**, off by default and gated on `valkeySubchart.enabled` (not `valkey.enabled`, which the subchart's strict schema rejects); never change `valkey/` and this chart in the same PR, see "Chart dependencies" |
 | `sure` | Sure (we-promise, the maintained Maybe-finance fork) | One StatefulSet with **two containers**: the Puma web process and a Sidekiq worker, sharing one ReadWriteOnce PVC at `/rails/storage` — that shared volume is the reason they live in one pod. Only the web container migrates (the image entrypoint runs `db:prepare` solely for the `./bin/rails server` command, so the worker is started through `args:` and skips it). Three 1Password items (app/database/redis); Postgres and Redis stay external. Readiness deliberately probes `/` rather than Rails' `/up`, which is a boot check and touches no database; the worker's three probes ask `sidekiqmon` for this pod's own heartbeat. `ingress.domain` is read for `APP_DOMAIN` and the WebAuthn relying party, so it stays required with the Ingress switched off |
 | `teamspeak-server` | TeamSpeak server | StatefulSet, no ingress |
 | `template-chart` | — | Scaffold for new charts (placeholder `xxx`), never published |