helm-charts/README.md

# helm-charts

Collection of some self-made helm-charts. Each top-level directory is a standalone Helm chart that gets packaged and uploaded to a private, classic (index-based) Helm registry by CI.

> **This repo lives on the Gitea instance JLab-Git.** Issues, pull requests, CI and Renovate all run there, and `main` there is the leading copy. github.com is a push mirror with Actions and Renovate **switched off**. The workflow files under `.github/workflows/` are read by Gitea unchanged; "Where this repo lives" below names the places where a Gitea runner behaves differently from a GitHub one, each of them measured rather than assumed.
>
> **The knowledge base is the [wiki](https://git.jk-dev.de/jlab-cluster/helm-charts/wiki).** It holds one page per chart — prerequisites, an installation walkthrough, the complete list of configurable values and the chart's operating traps — plus the long form of the workflow, the pipelines, the style guide and the [lessons](https://git.jk-dev.de/jlab-cluster/helm-charts/wiki/Lessons-Learned) each rule was bought with. This README stays the overview for someone reading the code; anything an *operator* needs is in the wiki. Keeping it current is a required step of the workflow (`CLAUDE.md`), not an afterthought.
>
> **A reading note on `#n`.** Issue numbers in this file point at the **GitHub** tracker. Most of them name *closed* issues, which were not migrated and exist only there. Gitea resolves a bare `#n` against its own counter instead — where, for example, `#22` is an unrelated throwaway pull request rather than the install-test issue this file means. The seventeen issues that were still open at the move are Gitea #5–#21 and #24; the mapping is a comment on Gitea #14.

## Charts

Every chart has a wiki page of its own — `https://git.jk-dev.de/jlab-cluster/helm-charts/wiki/<chart>` — carrying the installation walkthrough, the required 1Password fields and the full values reference. The table below is the one-line version.

| Chart | Deploys | Notes |
|---|---|---|
| `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 `{}`) |
| `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) |
| `gotenberg` | Gotenberg | Deployment + Service only (no ingress) |
| `homeassistant` | Home Assistant | StatefulSet; the only chart carrying Helm tests (`templates/tests/`) |
| `matrix-synapse` | Matrix Synapse | StatefulSet plus an nginx delegation Deployment/Service |
| `minecraft-router` | itzg/mc-router | Deployment + routing ConfigMap + NodePort Service (TCP only, no ingress); `mappings` is a required value |
| `minecraft-server` | itzg/minecraft-server | StatefulSet + PVC + Service + init-script ConfigMap (no ingress); service type is a value (`ClusterIP` by default, routed via `minecraft-router`). **Only the newest Java line is maintained** (chart 5.0.0, #158): the directory carries one line, older ones stay published as frozen artifacts (java8/java17 at `4.0.0`, java21 at `4.1.0`) and receive no further chart changes — publishing once per line out of one directory is what made the lines drift. To run an older JVM with the current chart, set `image.tagOverride`; the chart then checks that `minecraft.version` fits the Java line of the **effective** tag and fails the render with both values named. Two cases pass unchecked on purpose: a tag without a `java<N>` part and a `minecraft.version` that is not a plain numeric `x[.y[.z]]`. `image.tagOverride` is deliberately outside Renovate's reach — `renovate.json5` tracks `appVersion` only. Since chart 2.0.0 the tag is an **immutable dated upstream release** (`appVersion: <release>-java8` / `-java17` / `-java21` / `-java25`, e.g. `2026.8.2-java8`) instead of the continuously rebuilt rolling line tag. Pilot for the strict `values.schema.json` (#68), which is now binding for every chart |
| `outline` | Outline | StatefulSet, separate DB/Redis secrets |
| `paperless-ngx` | Paperless-ngx | Largest chart: consume CronJob, SMB-connector PV/PVC, pre/post-consumption scripts ConfigMap |
| `patchmon` | PatchMon | One Deployment (the 2.x server serves frontend and `/api/*` from one process) plus an optional guacd sidecar; OIDC-only sign-in |
| `rallly` | Rallly | Deployment, DB/OIDC/SMTP secrets |
| `rss-bridge` | RSS-Bridge | Deployment + whitelist ConfigMap; `ingress.hosts` is a required list of host + optional `tlsSecretName`, so several hosts can keep their own existing certificates (documented deviation from the one-TLS-secret rule, see its `values.yaml`) |
| `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 |
| `teamspeak-server` | TeamSpeak server | StatefulSet, no ingress |
| `template-chart` | — | Scaffold for new charts (placeholder `xxx`), never published |
| `urlaubsverwaltung` | Urlaubsverwaltung | Deployment, DB + OIDC secrets |
| `voucher-vault` | VoucherVault | StatefulSet, DB + OIDC secrets |
| `ytdlp-web-player` | ytdlp_web_player | Stateless Deployment, video cache and tool cache as emptyDirs (no PVC). **The only chart with a dependency**: an optional `oauth2-proxy` subchart, off by default, wired in front of the app because the application ships no authentication at all — see "Chart dependencies" below |
| `zipline` | Zipline | StatefulSet, DB secret |

## Versioning

`Chart.yaml` uses the scheme `version: <chart-semver>+up<app-version>` (e.g. `1.4.0+up1.9.2`) — see the [chart style guidelines](#chart-style-guidelines) for the full rules (suffix normalization, semver bump levels).

- Bump the **chart version** in every change that touches a chart directory — a push to `main` publishes the chart.
- **App-version updates go through PRs** (so the validate and install-test pipelines run). The manually dispatched `Change App-Version` workflow (rewrites `version:`/`appVersion:` and commits directly to `main`) exists but bypasses both pipelines. For app **major** jumps, update stepwise: first to the last release of the old major line (own PR, merge, publish), then to the newest major.

## CI/CD

- `publish-<chart>.yml` — one thin workflow per chart; triggers on pushes to `main` touching `<chart>/**` (or manually) and calls the reusable workflow below. **A push to a chart directory on `main` publishes that chart**, so the chart version must be bumped in the same change.
- `publish-helm-chart.yml` — reusable workflow: `helm package`, then a single HTTP `POST` of the packaged `.tgz` to the private chart registry. The target is a **classic, index-based** Helm registry (Gitea's `/api/charts` endpoint), not an OCI one: `helm push` speaks only OCI and is not used, there is no `helm registry login` session, and every request carries its own Basic auth. Credentials **and the target URL** come from 1Password Connect (`OP_CONNECT_TOKEN` secret, item `op://GitHub-Actions/jlab-registry-access/` with `username`, `password`, `charts-url`); the workflow appends `/api/charts` to `charts-url`. No registry address ever appears in this repository. The loaded values are read via **`steps.<id>.outputs.*`**, mapped into the step's own `env:` block and used as quoted shell variables — never interpolated into the command line. `load-secrets-action` **v5 no longer exports them as environment variables** for later steps the way v4 did, so after the v5 bump every `${{ env.* }}` reference resolved to an empty string while the loading step still logged `Populating variable` and stayed green. Each value is additionally guarded with `:?`, because an empty one used to collapse into a missing argument rather than an error. Three properties of the upload step are load-bearing:
  - **Credentials stay out of the process list.** `curl --user "$U:$P"` would put them in `argv`; the step uses `curl --config -` and pipes the options in on stdin instead.
  - **A failed upload fails the job.** Unlike `helm push`, `curl` exits **0** on HTTP 401/403/409 — a publish would go green with nothing uploaded. `--fail-with-body` turns those into a non-zero exit and still prints the response body, so the log names the cause.
  - **The file name is built, not globbed.** `<chart>-<version>.tgz` is assembled from the chart name and the version already read from `Chart.yaml`; `--upload-file` takes exactly one file, and a glob matching two silently turns the second into curl's URL argument. `helm package` keeps the `+` of a `1.4.0+up1.9.2` version verbatim in the file name, so the built name is an exact match.

  Note: the registry **accepts a re-upload of an already published version** (HTTP 201) and replaces the stored artifact, so a republish of an existing version is still silent — see #160.
- `change-app-version.yml` — manually dispatched app-version bump; the chart must be listed in its `chart-name` choice list.
- `ci/helm-dependencies.sh <chart-dir>` — not a workflow but the step they all share: fetches a chart's declared dependencies into `charts/`, and returns silently for the charts that declare none (all but one). It runs in **five** places, because every helm command this repo builds on exits 1 while a declared dependency is missing: before lint and package in `validate-charts.yml`, before package in `publish-helm-chart.yml`, and inside `ci/run-install-test.sh`, `ci/run-quantity-render-test.sh` and `ci/run-trivy-config.sh`. See "Chart dependencies" in the style guidelines for what that costs.
- `validate-charts.yml` — PR pipeline: detects which charts a PR touches and, for exactly those, runs `helm lint --strict`, `helm package`, and a chart-version bump check (`template-chart` is exempt from the version check). PRs without chart changes skip the build matrix. After the build stage, an **install-test** job (the same changed-charts matrix, minus the charts listed in `ci/excluded-charts.txt`) installs each changed chart into an ephemeral [k3d](https://k3d.io) cluster on the runner and requires every workload to become Ready — see below. Both matrices follow the changed chart directories, so a PR that only changes the harness under `ci/` exercises nothing by itself; the Trivy scan has a fixed-sample fallback for that case, the install-test has none — bump the affected chart's patch version to pull it into the matrix. The **resource-quantity render test** is the exception to that rule: it runs over every chart on every PR — see below.

### Where this repo lives, and what a Gitea runner does differently

Everything below was measured on this instance, not taken from documentation, and it is the reason for every deviation in `validate-charts.yml`. How the move got here is not repeated — that is Gitea #14.

**Reusable workflows with `secrets: inherit` work**, so the 23 thin `publish-<chart>.yml` hulls run unchanged. One quirk worth knowing before debugging the wrong thing: a *missing* secret does not fail the job, it fails job **creation**, so the run shows no steps at all.

**Runner labels mean different machines than on GitHub.** `ubuntu-latest` here has **no Docker socket**; `ubuntu-docker` has one. Exactly one job cares — the install-test, because k3d is a Docker client — and its `runs-on` is therefore an expression rather than a fixed label, so the same file still works on a GitHub runner where `ubuntu-docker` does not exist. Every other job (lint/package, the quantity render, the Trivy scan) needs no socket and stays on `ubuntu-latest`.

**A matrix runs concurrently inside ONE job, under ONE status context.** This is the single most consequential difference and it has two halves. Operationally: all legs share one Docker daemon, which is what makes a per-leg resource name mandatory (see the cluster name below). For branch protection: **a required check per chart is not possible**, because there is only one context for the whole matrix — and its name carries the *unexpanded* matrix expression, e.g. `Validate Helm Charts / Install-test ${{ fromJSON(needs.detect-changed-charts.outputs.install-charts) }} (pull_request)`. Required-check names have to be read off a real run; they cannot be copied from GitHub. What *is* required on `main` today is **`validate-charts`**, as the single context it reports under, alongside a **review**: per chart is the part that is impossible, not required checks as such. Both are what makes Renovate's `platformAutomerge: true` safe — see "PR policy".

**Expected runtimes**, so that a later deviation is visible as one:

| | measured here | GitHub, same commit |
|---|---|---|
| `Create k3d cluster` | 19–25 s | 22–23 s |
| `install-test` job, two charts in the matrix (cyberchef + freesailarr) | 210–216 s over three runs, spread 6 s | ~145 s wall, two parallel VMs |
| `install-test` job, freesailarr alone, ten containers and a real tunnel | 225 s (measured on the MediathekArr change, Gitea #20) | not comparable — Actions there were already off |

The runner is **not slower** — cluster creation is a touch faster. The difference in total time is **structural, not performance**: two matrix legs share one runner here, while GitHub gives each leg its own VM. Reading it as "Gitea is slower" leads to the wrong conclusion.

**`aquasecurity/setup-trivy` cannot be used.** It runs `actions/checkout` against `aquasecurity/trivy` on github.com and hands it `github.token` — which here is a *Gitea* token. github.com answers 401 and checkout ends on `fatal: could not read Username for 'https://github.com'`, naming neither the action nor the token. Its `actions/cache` step is inert here as well. The workflow downloads the release tarball instead: one request, same behaviour on either forge.

**Tools are installed, not inherited — and the two cases differ on purpose.** `kubectl` is **pinned** to match `K3S_IMAGE` and guarded against version skew, because a client's distance to the API server changes what the test *means*, and a version that arrives with the runner image drifts with every image rebuild. `envsubst` is only **checked for and fetched if absent**, because it substitutes text and the release doing so does not change the result; pinning it would be upkeep without value. That GitHub's image happens to ship both does not make either unnecessary — it only makes the drift invisible there.

**Containerisation is detected, not inferred from the platform.** k3d publishes the API server port on the Docker *host*; when the job is itself a container — as every Gitea Actions job is — that host is the dind container, so the `https://0.0.0.0:<port>` k3d writes into the kubeconfig points at the job container, where nothing listens. The workflow asks the daemon about its own container instead of asking which forge it is on: a self-hosted **GitHub** runner in a container has the identical problem, and a condition that says "GitHub" while meaning "not containerised" is the kind of lie this repo exists to remove.

Still unmeasured, because they never stood in the way: `/dev/fuse` and user namespaces. Said as unmeasured rather than as fine.

#### What a GitHub runner had been providing quietly

Getting the install-test to run here surfaced six assumptions that had never been written down anywhere. Five of them say something about the **runner**, one about **our code**, and the split is the point.

The five environment ones are the harmless kind: they fail loudly, immediately, and are fixed on the node side (`cluster-config`), not here — Docker bridges built at MTU 1500 against a pod network of 1450 (small responses fit in one packet, a 17 MB tarball does not, which is why it looked like a blocked host); `fs.inotify` limits too low for k3s, so containerd never started and the node never registered; no `kubectl` and no `envsubst` in the image; and the kubeconfig pointing at `0.0.0.0`.

The sixth is different, and it is the one to remember.

> **The k3d cluster name was hard-coded as `install-test` — and that was wrong on GitHub too.** It simply could never show there: each matrix leg gets its own VM with its own Docker daemon, so two legs never saw each other's cluster. Here, where all legs share one daemon, it collides immediately — one leg logs `Re-using existing network`, the other dies on `The container name /k3d-install-test-server-0 is already in use`, and the first leg's rollback then deletes the shared network out from under the second. Two red legs, and neither message names the cause.
>
> For two years the roomier environment carried that bug instead of showing it. **A generous environment is no friend when you want to know whether something is correct.**

#### Two rules for every check added here

Both were learned by getting them wrong in this repo, and both apply to any new verification step, not just to clusters.

1. **A check that a broken system passes is worse than no check.** `kubectl get nodes` exits **0 on an empty list**, so a readiness check written that way went green against a cluster whose node had never registered — and the failure then surfaced five minutes later, somewhere unrelated. `kubectl wait --for=condition=Ready nodes --all` is not the shorter way to write it: with zero nodes the condition is vacuously satisfied. Assert the thing you mean (*at least one node, and Ready*), not that the command answered.
2. **Green does not mean checked.** A passing job earns exactly as much trust as the assertions inside it. The open case of this kind is Gitea #24: the images in `ci/<chart>/fixtures.yaml` are not followed by Renovate, so the install-test can keep passing against fixture infrastructure that is years stale. **Not solved** — named here so it is not mistaken for solved.

### Resource-quantity render test (all charts, every PR)

`ci/run-quantity-render-test.sh [chart …]` (no argument = all charts) renders every chart twice with the fixtures the install-test and the Trivy scan already use, injecting a bare integer memory request at **every** `resources` block the chart's `values.schema.json` declares:

| Case | Injected | Expected limit | Catches |
|---|---|---|---|
| `bare-int` | `requests.memory: 1048576`, `limitFactor: 2` | `2097152` | render aborts |
| `fraction` | `requests.memory: 999999`, `limitFactor: 1.5` | `1499998.5` | quantity in exponential notation |

The two cases exist because the bug behind #157 — quantities formatted with `printf "%v"`, where the `float64` the null-safe fallback helpers produce flips to exponential notation from about `1e6` — has a loud and a silent half. Loud: the reformatted quantity carries the suffix `e+06`, the helper rejects it, `helm template` exits non-zero. Silent: the *product* of a fractional `limitFactor` and a bare number is reformatted **after** the suffix check, so the render succeeds and the manifest carries `memory: "1.4999985e+06"` — rejected by nothing until the API server sees it at apply time. A check on the exit code alone therefore proves only half the case; the second case searches the **rendered text** for a resource quantity in exponential notation. `999999` stays below `1e6` on purpose, so the fraction case isolates the second formatting site instead of tripping over the first.

Why all charts rather than the changed ones: the resources helper is copied into every chart's `templates/_helpers.tpl` rather than shared through a library chart. The regression arrives by copy — a new chart started from an older chart, or from `template-chart` before the fix — and in that PR the copied bug is in no diff anyone reads. Running over everything also removes the list nobody would maintain: adding a chart enrolls it automatically. Two renders per chart, no cluster, a few seconds for the whole repo; the job depends on nothing else and finishes well inside the `build-chart` runtime.

Two details worth knowing before touching it:

- **The resources paths come from `values.schema.json`, not `values.yaml`** — it is JSON, so `python3` reads it without pyyaml (same runner constraint as `ci/run-trivy-config.sh`), and every chart-owned key must appear there anyway. A block counts when it is `#/definitions/resources` or carries `limitFactor`/`requests` itself, which is what keeps `minecraft-server`'s JVM-sizing `minecraft.resources` out. A chart whose templates render a resources block while its schema declares none **fails** the test with exactly that message: the schema is then out of sync with the chart.
- **A chart that never reaches the helper is reported, not counted as passing.** `gotenberg` sets every computable limit explicitly in its fallback defaults, and since a `null` never deletes a default there, no override can free them — nothing is multiplied, so nothing is proven. Those charts appear under "helper not reached" in the job summary rather than as a green tick for a code path that was never entered.

### Install-test (PR pipeline stage 2)

For every chart a PR changes, `ci/run-install-test.sh <chart>` runs against a throwaway k3d cluster: it applies the stub `OnePasswordItem` CRD plus the chart's fixtures, `helm install`s the chart with its CI values, and waits for all Deployments/StatefulSets to roll out (per-chart timeout). Since probes and security hardening are active on all workloads, "Ready" means the app actually answers. On failure the job dumps pod descriptions, events and container logs.

Fixtures live at the **repo root** under `ci/` (deliberately *not* inside the chart directories, so they are neither packaged into the chart tgz nor trigger the publish workflows on merge):

- `ci/common/` — fixtures applied for every chart (schema-less stub CRD for `OnePasswordItem`)
- `ci/<chart>/test-values.yaml` — values for the CI install (required for every installable chart)
- `ci/<chart>/fixtures.yaml` — dummy secrets with in-cluster connection data, throwaway infrastructure (postgres/redis/dex), static hostPath PVs/StorageClasses where the chart pins a storage class or needs RWX, and seed jobs (e.g. `synapse generate`)
- `ci/<chart>/fixtures.env.yaml` — fixtures that need a value which must not be committed. The file holds `${VARIABLE}` placeholders and nothing else; `ci/run-install-test.sh` renders it with `envsubst` and pipes the result straight into `kubectl` (never printed). Substitution is restricted to the names from `REQUIRED_ENV`, so an undeclared variable is never filled in and no unrelated `$…` in the manifest is touched
- `ci/<chart>/settings.env` — optional overrides: `INSTALL_TIMEOUT` for slow starters, and `REQUIRED_ENV="VAR_A VAR_B"` to declare the variables `fixtures.env.yaml` needs. **A missing or empty declared variable fails the install-test loudly, naming the variable — it never skips the chart.** Skipping would restore exactly the green-but-meaningless signal this mechanism exists to remove; the one legitimate case of absent secrets, a PR from a fork, belongs in an `if` on the workflow job rather than in the script
- `ci/excluded-charts.txt` — charts that cannot run in CI, one per line as `<chart> <justification>`. Currently: `satisfactory` (multi-GB image + 10GB+ Steam download), `template-chart` (scaffold with placeholder image). The justification is mandatory: a line carrying only a chart name is deliberately **not** an exclusion, because a bare name would drop a chart out of CI with nothing to review. **An excluded chart gets no install-test job at all** — see below

`freesailarr` is the only chart using `fixtures.env.yaml` today: gluetun needs a real Wireguard key, or it never completes a handshake and no app container behind its kill switch becomes Ready. The install-test job loads the key from 1Password Connect for that chart only, using the same pattern as `publish-helm-chart.yml` — `steps.<id>.outputs.*` into the step's own `env:`, quoted, with `:?` guards that name the missing `op://` field before the cluster is even created. The key in that item is a **CI-only Mullvad key**, deliberately not the production one: Mullvad ties an address to a key and routes the tunnel to the endpoint it saw last, so a shared key would make every PR run pull the tunnel out from under the running stack — with the symptom in the cluster and the cause in a pull request.

**An excluded chart is dropped from the matrix, not skipped inside its job (#231).** It used to get a job that ran the script, printed `SKIP` and exited 0 — and GitHub knows only the exit code, so the check list showed `Install-test satisfactory ✓` for a chart whose image was never pulled, indistinguishable from one that really came up in the cluster. `detect-changed-charts` now removes the excluded charts before the matrix is built, so no job exists for them and nothing claims they passed. Because an absence on its own says nothing, that job writes every excluded chart of the PR **with its documented justification** into the job summary — a `Skipped` would only say "not run", and why is the question a review actually asks. The list is parsed in exactly one place: `ci/run-install-test.sh --list-excluded` emits `<chart><TAB><reason>` and the workflow calls it instead of re-implementing the format in YAML, since a second parser would be a second chance to select different charts — silently, and in either direction. The script keeps its own `SKIP` branch for local runs. What cannot be done instead: deciding per chart in an `if` on the install-test job, to get a visible `Skipped` entry rather than an absent one. GitHub rejects it with `context "matrix" is not allowed here` — `jobs.<id>.if` is evaluated **before** the matrix is expanded, so the `matrix` context does not exist there, and the whole workflow ends in failure with zero jobs created (measured on the closed PR #233).

Fixture images avoid Docker Hub where possible (`public.ecr.aws`/`ghcr.io`) to dodge runner rate limits. The job **blocks the PR** on failure — the stabilization phase of #22 ended when Renovate started automerging patch/minor updates, since a chart that no longer starts must not reach `main` and publish unattended. When adding a new chart, add its `ci/<chart>/` fixtures (or an entry in `ci/excluded-charts.txt`) — the install-test fails if both are missing. The script also runs locally against any existing cluster: `k3d cluster create t && ci/run-install-test.sh <chart> && k3d cluster delete t`.

## Dependency updates (Renovate)

Renovate runs as the shared `jlab-renovate-bot` instance on the Gitea side, which also serves the other repositories there — see "Renovate on Gitea" below. **There is no Renovate workflow in this repo, and none should be added.** (The `jlab-renovate` GitHub App that used to do this is switched off along with the rest of GitHub Actions.) What updates is unaffected either way: the config is **`renovate.json5`** in the repo root (JSON5 for the inline reasoning; requires Renovate >= 41 for `managerFilePatterns`/`customType`). There must be exactly one config file — do not add a second `renovate.json` or `.github/renovate.json`.

What Renovate keeps current:

| What | How |
| --- | --- |
| Chart app versions (`appVersion:` in `Chart.yaml`) | One `customManagers` entry per chart, hard-coding the image repository |
| Sidecar/init images in `values.yaml` (nginx, guacd, busybox, alpine) | Built-in `helm-values` manager |
| **All** images of `freesailarr`, including its main one | Built-in `helm-values` manager — the chart pins every tag in `values.yaml` and has no app-version block. One exception: `mediathekarr` is pinned by **digest** (its tags carry no version) and has its own `customManagers` block |
| GitHub Actions | Built-in `github-actions` manager |
| Tool versions pinned as workflow env vars (`TRIVY_VERSION`) | `# renovate: datasource=… depName=…` comment above the line |

Each chart renders its main image as `<repo>:{{ .Chart.AppVersion }}` — repository in the template, version in `Chart.yaml`. Renovate cannot join two files, so the mapping lives in `renovate.json5`, one block per chart. It is deliberately *not* a `# renovate:` comment inside each `Chart.yaml`: that would touch all chart directories and force a version bump plus a publish per chart for a pure comment change. Charts whose tags carry a flavour or date suffix (`apache-tika`, `minecraft-server`, `rss-bridge`, `searxng`, `teamspeak-server`) override `versioning` in their block; the reasoning sits next to each one.

One rule those overrides share, learned from `searxng` and worth knowing before writing the next one: **a capture group is a claim about how the value is compared.** Renovate's regex versioning parses `major`, `minor`, `patch`, `build` and `revision` with `Number.parseInt` (`modules/versioning/regex/index.js`, `_parse`), so a non-numeric commit hash captured as `build` becomes whatever digits lead it — `9fea41204` is `9`, `777ba8fa4` is `777`, and a hash starting with a letter is `NaN`. Measured on renovate 41.173.1 and 44.48.0, that makes Renovate offer an image pushed *earlier the same day* as an update to a newer one — a downgrade wearing the clothes of a routine date bump, which is exactly what a review waves through and automerge then carries to `main`. Parts of a tag that carry no ordering belong **outside** every group: the anchored pattern still requires them to be there, they simply take no part in the comparison. `prerelease` is not the way out either — it sorts correctly but marks every tag `isStable === false`, which hands the whole chart to `ignoreUnstable`. `freesailarr` has no **app-version** block on purpose — see the images exception above; a block would either duplicate the `helm-values` updates or rewrite an `appVersion` that selects no image. It does carry one `customManagers` block, for `mediathekarr`: that image is pinned by digest because its tags carry no version (`latest` is a 2024 build, `beta` moves), and the built-in `helm-values` manager reads only `repository`/`tag` and skips it (`skipReason: invalid-value`), so the two cannot collide. Digest rules need the same guard as versioning rules and for a sharper reason: while the pin is current, a matching rule and a broken one produce the identical empty result. Verified with two dry-run fixtures — the real digest yields no update, a deliberately stale one yields exactly one `digest` update back to the pinned digest.

A consequence of pinning every tag in `values.yaml`: `ci/renovate-bump-chart.sh` sees an unchanged `appVersion` and bumps the chart **patch**. That holds for all ten images alike, the digest-pinned one included — none of them is special — and it is the intended outcome, since `appVersion` here is the chart's own marker rather than a tracked upstream version.

Two dependencies are constrained beyond their versioning. **nginx** (the Synapse delegation sidecar) is limited to **even minors** via `allowedVersions`. nginx numbers its release branches by minor — even is stable, odd is mainline — and the chart belongs on stable. Patch updates inside the stable branch still flow through normally. The constraint tolerates a variant suffix (`1.30.4-alpine`) on purpose: docker versioning only ever offers candidates carrying the current tag's suffix, so a suffix-blind constraint would silently freeze nginx the day the sidecar moves to a slimmer base image — a switch to `1.30.4-alpine` that #84 has commissioned a check on — with no error and no warning.

**linuxserver/qbittorrent** (freesailarr) excludes two tags by name, `14.3.9` and `20.04.1`. They are leftovers from earlier linuxserver tagging schemes, and docker versioning sorts both above every real release, so Renovate offers them as major updates — PRs #152 and #153 were exactly that. They are named rather than cut off with an upper bound like `<10`, because a bound would eventually reject a genuine major, while two finished artifacts cannot grow and therefore cannot hide a future release. The same guard as for nginx applies and was run: a lookup from `currentValue 4.6.4` still offers `5.2.3` as a **major**, so the filter does not silently empty the update list. That fixture also shows the cost of leaving it alone — without the rule the very same lookup offers `20.04.1` and never mentions the real `5.2.3`, since Renovate fills the major bucket only once.

Not managed: `ci/**` (install-test fixtures pin throwaway infrastructure to major lines on purpose) and `template-chart/**` (placeholder image). A consequence worth knowing: `ci/matrix-synapse/fixtures.yaml` pins a Synapse image that Renovate will not follow — bump it by hand when the chart moves a major.

### The version-bump hook

Renovate only rewrites `appVersion:` or an image tag; it knows nothing about `version: <chart-semver>+up<app-version>`. Left alone, every chart PR would fail the `build-chart` version check. `ci/renovate-bump-chart.sh <chart-dir>` closes that gap and is wired up as a `postUpgradeTasks` command:

- **app major changed** → chart major (`6.0.0` → `7.0.0`), matching "runtime behavior changes" in the semver conventions
- **anything else** (plain app update, sidecar image) → chart patch
- the `+up` suffix is recomputed from the new `appVersion`, dashes normalized to dots

Everything is derived from the base commit, so the script is idempotent across the multiple updates a single Renovate branch can carry.

> **One-time setup outside this repo:** `postUpgradeTasks` only runs on self-hosted Renovate **and** only when the command is allow-listed in the *instance* config:
>
> ```yaml
> allowedCommands: ["^ci/renovate-bump-chart\\.sh"]
> ```
>
> Without that entry Renovate skips the task without an error and every chart PR stays red on the version check.

If the dependency dashboard reports `Failed to look up github-releases package …: no-result` for third-party repos, that is the instance's github.com credentials, not this config. The instance needs a read-only PAT as `GITHUB_COM_TOKEN` for github.com datasource lookups; its own platform token is a Gitea token and is worth nothing there.

### Renovate on Gitea

**Do not add a Renovate workflow to this repository.** It is the obvious thing to reach for — Gitea has no app model, so a scheduled job in the repo looks like the only way to run the bot — and it is wrong here: a **shared `jlab-renovate-bot` instance** runs outside this repository and has it enrolled. A second runner against the same repo produces duplicate PRs and two schedulers rewriting each other's branches, which is not a safety net but a fault. This paragraph exists so the next reader who finds no workflow knows why instead of building one.

The instance is outside this repository, which has two consequences worth writing down:

- **It reads our `renovate.json5` and the per-chart rules do fire.** Measured, not assumed: its first run here opened PRs for `searxng` and `gotenberg` plus the dependency dashboard. Those two are `customManagers` targets of ours — no built-in manager finds an `appVersion:` in a `Chart.yaml` — so the config is demonstrably in effect.
- **`allowedCommands` is already granted there, and the version-bump hook runs.** This was the expensive unknown: `postUpgradeTasks` only executes when the command is allow-listed in the *instance* config, and a missing entry is skipped **silently**, leaving every chart PR red on the version check. The proof is in that searxng PR's diff, which carries `version: 1.0.4+up2026.9.11.ffe96f8a6` → `1.0.5+up2026.9.13.96479fff6` alongside the `appVersion` change. Nothing but `ci/renovate-bump-chart.sh` writes `version:`. The allow-list is not visible from this repo, though, so if it is ever dropped the symptom here will be red chart PRs with no explanation.

One item is easy to miss and is named in "The version-bump hook" above: the instance needs a `GITHUB_COM_TOKEN` for github.com datasource lookups. Every `github-releases`/`github-tags` lookup and the whole built-in `github-actions` manager resolve against github.com, the platform token is a Gitea one and worth nothing there, and unauthenticated lookups hit the rate limit inside a single pass. The symptom is a `no-result` line on the dependency dashboard, not an error.

### PR policy

The config is aligned with the one in `cluster-config`, because the same `jlab-renovate-bot` instance serves both and two repos that behave differently under one bot is a source of surprises rather than of safety.

- **Automerge is global** (`automerge: true`, `automergeType: "pr"`, `platformAutomerge: true`) — every update type, **majors included**. The safeguard is not the absence of automerge, it is the branch protection: `main` requires a **review** and requires `validate-charts` to pass. `platformAutomerge` arms the PR on the forge, and Gitea merges it when *both* conditions are met, so an armed PR without a review simply sits there. This is the setting the older `platformAutomerge: false` comment in `renovate.json5` named as the better one "once required checks exist on `main`" — they now do. Same reasoning as `cluster-config`, which retired its dashboard-approval step for it.
- **`minimumReleaseAge: "3 days"`** for `patch`, `minor` and `digest` updates. Renovate does not even open the PR before then. A merge here is never just a merge — a chart publish follows it straight away — so a release that gets yanked hours after it appeared must not reach the registry. Majors carry no age gate: they are held at the review, not by a delay.
- **Majors** arrive one line at a time (`separateMultipleMajor`): a v1 → v3 jump produces a PR for the latest v2 first and then one for v3 — the stepwise procedure the versioning section requires. `separateMinorPatch: true` likewise splits minor and patch into separate PRs, so one red install-test does not block unrelated updates.
- **No PR caps** (`prConcurrentLimit: 100`, `prHourlyLimit: 0`), as in `cluster-config`. The known cost, written down rather than discovered: the first run after a quiet week can open many PRs at once, and every chart PR starts a k3d install-test — which on a Gitea runner queues inside one job rather than fanning out (see "Where this repo lives"). That queue is the accepted trade for not having updates trickle in four per hour.
- **`config:best-practices`** is in `extends`. Two of its members matter here: `helpers:pinGitHubActionDigests` moves the workflow files from `actions/checkout@v7` to SHA pins (wanted), and `docker:pinDigests` is switched off again for `custom.regex` and `helm-values` — an `appVersion:` is a tag by construction (`<repo>:{{ .Chart.AppVersion }}`, and the `+up` suffix is built from the same string), so a digest has nowhere to go. Sidecar digests in `values.yaml` *could* be pinned; that is a separate decision, since each digest change would be a chart patch plus a publish.
- The manually dispatched `change-app-version.yml` still exists for one-off bumps, but the normal path for app updates is now a Renovate PR.

## Creating a new chart

The wiki carries the same procedure as a worked checklist: [Creating a new chart](https://git.jk-dev.de/jlab-cluster/helm-charts/wiki/New-Chart). A new chart also needs a wiki page of its own before its PR is merged.

1. Copy `template-chart/` to `<chart-name>/` and replace every `xxx` placeholder: template file names (`xxx.deployment.yaml` → `<app>.deployment.yaml`), `Chart.yaml`, the `values.yaml` keys, the `.Values.xxx.*` references inside the templates, **and both the `xxx.` helper prefixes and the values paths in `values.schema.json`**. Then walk the six points in "Values that must not lie" below — the schema and the null-safe fallbacks are copied with the template, but their content is chart-specific and wrong until you adapt it. The same goes for `templates/NOTES.txt`: it comes with the template as a worked example and is placeholder text until you replace it with what an operator of *your* app needs after the install (see "Everything else" below); its leading `{{/* … */}}` block explains the bar and is meant to be deleted.
2. Add `.github/workflows/publish-<chart-name>.yml` (copy an existing one, e.g. `publish-outline.yml`).
3. Add the chart name to the choice list in `.github/workflows/change-app-version.yml`.
4. Add a `customManagers` block for the chart's main image in `renovate.json5` (copy a neighbouring one, swap `managerFilePatterns` and `depNameTemplate`) — without it the chart's app version is never updated. Check the image's tag list first: if it carries a flavour, date or prerelease suffix, add a `versioningTemplate` with a comment saying why. **Floating tags belong outside the pattern**: `ytdlp-web-player` anchors its versioning regex on the `v` prefix precisely so `latest` and `stable` — both of which move — can never be selected.
5. Only if the chart needs a **dependency**: read "Chart dependencies" in the style guidelines first, it is a bar rather than a formality. Nothing has to be added to the pipelines — `ci/helm-dependencies.sh` already runs everywhere and keys off the `dependencies:` block — but the subchart's own updates then depend entirely on Renovate's built-in `helmv3` manager plus a chart-version bump, which is the part to write down at the pinned version.

Validate locally with:

```bash
helm lint --strict <chart-name>
helm template <chart-name> --set ingress.domain=example.com --set ingress.clusterIssuer=letsencrypt
```

(required values vary per chart)

For runtime verification (do the workloads actually start, do probes/security settings hold?), use a throwaway local [k3d](https://k3d.io) cluster: `k3d cluster create <name>`, apply a stub CRD for `OnePasswordItem` plus dummy secrets (and throwaway postgres/redis pods where the app needs them), `helm install` the chart, watch pod readiness/events, then `k3d cluster delete <name>`.

## Chart style guidelines

These guidelines are **binding for every current and future chart** in this repo. They are the consolidated end state of the conventions overhaul (#32, batches 0–4); `template-chart/` is the reference implementation. The wiki mirrors them as the [chart style guide](https://git.jk-dev.de/jlab-cluster/helm-charts/wiki/Chart-Style-Guide), with the incident behind each rule collected in [Lessons learned](https://git.jk-dev.de/jlab-cluster/helm-charts/wiki/Lessons-Learned) — change a rule here and update that page in the same PR.

### 1. Naming

- Resources are named `{{ .Release.Name }}-{{ .Chart.Name }}-<kind>` (e.g. `...-deployment`, `...-sfs`, `...-service`, `...-secret`, `...-configmap`, `...-ingress`, `...-pvc`).
- Template files are named `<app>.<kind>.yaml`; stateful apps use a StatefulSet in a `<app>.sfs.yaml` template instead of a deployment.
- **Documented exception — existing PVC names**: PVCs of already-published charts keep their historical names even where they deviate from the scheme. Renaming a PVC makes Kubernetes provision a new, empty volume, so a rename would orphan the existing data. New charts name PVCs `{{ .Release.Name }}-{{ .Chart.Name }}-pvc` per the scheme.
- StatefulSet renames are possible (data survives because the charts use standalone PVC templates, not `volumeClaimTemplates`) but only ship in a major-bump PR with a one-time migration note: `kubectl delete statefulset <old> --cascade=orphan` (and delete the leftover old pod) before upgrading.

### 2. Versioning

- `Chart.yaml` uses `version: <chart-semver>+up<appVersion>`; the `+up` suffix matches `appVersion`, with dashes normalized to dots (e.g. `0.0.36-beta` → `+up0.0.36.beta`). `appVersion` is the **exact image tag** of the main app image.
- Semver rules for the chart part:
  - **Patch**: bug fixes without behavior or values-schema change; plain app-version updates.
  - **Minor**: additive, backward-compatible changes (new optional values with unchanged defaults).
  - **Major**: runtime behavior changes or breaking values changes (e.g. resource renames, probes, security hardening, values that become required).
- Any push to `main` touching a chart directory publishes that chart, so the version must be bumped in the same change.

### 3. Images

- The main app image tag comes from `{{ .Chart.AppVersion }}` — never hardcoded.
- **Documented exception — freesailarr**: the chart bundles ten independently versioned upstreams (nine of them enabled by default), so none of them is "the" app version. **No** tag comes from `appVersion`; every image is pinned as `<app>.image.repository` / `<app>.image.tag` in `values.yaml`, which is also what puts them under the built-in `helm-values` manager. Its `appVersion` is the chart's own version marker, freely chosen and tied to no upstream — raised by hand when a new edition of the chart is marked as a whole. Consequently the chart has **no app-version** block in `renovate.json5` and is **not** in the `change-app-version.yml` choice list. `mediathekarr` adds a second deviation on top: its tags carry no version at all, so it is pinned by `image.digest` as well and is the one image in this chart with a `customManagers` block — a `repository`/`tag` pair alone would leave it without any update path.
- **Documented exception — minecraft-server**: the only chart whose main image tag can be overridden, through `image.tagOverride` (#158, empty by default — the tag still comes from `appVersion`). `appVersion` is the tag and therefore fixes the JVM, and since chart 5.0.0 only the **newest** Java line is maintained out of this one directory; the older lines stay published as frozen chart versions (java8 and java17 at 4.0.0, java21 at 4.1.0) and never receive another change. Without the override, running an older JVM would mean installing a frozen chart and giving up every later fix — so the line is a decision at rollout time rather than a property of the chart. The override is named `tagOverride`, not `tag`, because it decouples the running image from the chart version, and it is deliberately outside Renovate's reach (`renovate.json5` tracks the `appVersion` in `Chart.yaml` and nothing else). The chart checks the pairing itself: the Java line of the **effective** tag against `minecraft.version`, failing the render with both values named — a mismatch used to install silently and only break the container afterwards.
- Auxiliary images (sidecars, init containers, secondary workloads — e.g. the delegation nginx in matrix-synapse, guacd in patchmon, busybox init/consume images in paperless-ngx) are pinned via values instead of being hardcoded in templates, and their pinned versions are reviewed alongside every app-version update round.

### 4. Ingress

- `ingress.domain` and `ingress.clusterIssuer` (cert-manager) are `required` values **without defaults** — every installation sets both explicitly; they are the only values needed for a default install.
- `ingress.className` selects the ingress class and defaults to `nginx`.
- `ingress.annotations` takes optional extra annotations that are merged with the cert-manager `cluster-issuer` annotation the chart always sets.
- The TLS secret is named `tls-<release>-<chart>-ingress`.
- **Documented exception — homeassistant**: keeps its upstream-style flexible ingress values (host/tls lists, no required values); only its `ingress.className` default follows the standard (`nginx`, clearable to omit the field).
- **A shared domain with sub-paths is the second admissible ingress shape.** Where a chart exposes several apps, they may either each take a host of their own or share one host and be told apart by path (`domain.tld/sonarr`, `domain.tld/radarr`, …) — one DNS name and one certificate for the whole bundle. The rules for the shared shape: the domain is a single value (`ingress.host`), each app's path is its own value defaulting to `/<app>`, the paths render in one Ingress object `<release>-<chart>-ingress` with the standard TLS secret `tls-<release>-<chart>-ingress`, and an app that carries a host of its own always wins and keeps its own object — so both shapes mix without extra values. An app that needs a per-path proxy annotation (`rewrite-target` is per **object**, not per path) gets its own object on the same host, repeating the same TLS secret name and **omitting** the cert-manager annotation, so that exactly one certificate is requested. Apps that cannot serve a base path must be rendered at `/` or refused with a `fail` — never rendered somewhere they provably cannot work.
- **Documented exception — freesailarr**: the chart bundles several independently exposed apps in one pod, so it has **no** `ingress.domain`. It offers both shapes. By default each app carries its own `<app>.ingress.enabled` plus a required `<app>.ingress.host` (required only while that app's ingress is enabled and it is not on the shared domain) and renders its own Ingress object `<release>-<chart>-<app>-ingress` with its own TLS secret `tls-<release>-<chart>-<app>-ingress`. Setting the global `ingress.host` switches every app without a host of its own to the shared-domain shape under `<app>.ingress.path`; qBittorrent (no base path, needs a prefix-stripping rewrite) gets the extra object described above, and seerr as well as mediathekarr are pinned to `/` — mediathekarr because its UI links assets with root-absolute paths, which a rewrite cannot fix; with both of them on one shared host the duplicate-path guard fires and one of them needs a host of its own (its ingress is therefore off by default). `clusterIssuer`, `className` and `annotations` stay global defaults under `ingress.` and are overridable per app.

### 5. Security hardening

- Defaults on every workload: `automountServiceAccountToken: false`, non-root user, `readOnlyRootFilesystem: true`, all capabilities dropped, `allowPrivilegeEscalation: false`.
- Pod and container contexts are values-configurable via `securityContext.pod` / `securityContext.container`.
- Writable paths (e.g. `/tmp`, nginx cache dirs, s6-overlay's `/run`) are emptyDirs so the root filesystem stays read-only.
- Where an image cannot satisfy the full standard (e.g. Home Assistant must start as root for s6-overlay, paperless needs a root init container to hand over `/run`, samba needs its capabilities), the deviation is minimal and **must** be justified with a comment in that chart's `values.yaml`.

### 6. Probes

- Every workload has liveness, readiness and startup probes (documented exception: the paperless-ngx consume CronJob).
- Probes are values-configurable with calibrated defaults (the startup probe gates liveness/readiness; its budget is documented in a values comment per chart).

### 7. Resources (auto-limits)

- Resource requests ship as chart defaults in `values.yaml` and are user-overridable.
- Limits are computed by a per-chart `_helpers.tpl` helper (reference implementation in `template-chart/templates/_helpers.tpl`): an explicitly set limit always wins, missing memory and ephemeral-storage limits default to `resources.limitFactor` × the request (factor default `3`), and a CPU limit is only rendered when set explicitly — otherwise CPU stays unlimited (it is compressible, throttling instead of OOM-killing). The helper is copied into every chart rather than shared through a library chart — which would be a second artifact to publish, version and pull for a helper that changes about once a year; the resource-quantity render test above exists because a copy can carry an old bug into a diff nobody reads.

### 8. Secrets

- Secrets are **1Password `OnePasswordItem` CRs**: values expose `secrets.<name>SecretRef` holding an `op://` item path; the 1Password operator materializes the Kubernetes Secret in-cluster.

### 9. Config changes must restart the workload (#82)

- **Every workload that consumes a ConfigMap carries a `checksum/config` annotation on its pod template** — one line per ConfigMap it consumes:

  ```yaml
  template:
    metadata:
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/<chart>.configmap.yaml") . | sha256sum }}
  ```

  Reference implementation: `template-chart/templates/xxx.deployment.yaml` and `xxx.sfs.yaml`. Where a workload consumes several ConfigMaps, use one annotation per file with a distinguishing suffix (`checksum/config-<name>`).
- **Why it is mandatory, not optional**: without it a changed ConfigMap does not change the pod template, so nothing restarts and the running container keeps the old config — silently. `subPath` mounts (the usual form here) are never refreshed by the kubelet at all, and most apps read their config only at start. In #82 this produced a real outage: the router kept routing to Services that no longer existed while every bundle was green and the pod was Ready.
- **The annotation is content-based, not time-based**: the hash is taken over the rendered ConfigMap, so an unchanged config renders an identical hash and `helm upgrade` is a no-op. It never degenerates into a restart-on-every-upgrade.
- Adding the annotation to an existing chart is a **major** bump (§2): runtime behavior changes — a config change now costs a restart. Name that cost in the PR (some workloads take minutes to come back).
- **Secrets from `OnePasswordItem` cannot use this mechanism.** Helm never sees their content — the 1Password operator fills the Secret in-cluster after rendering, so there is nothing to hash. A chart that mounts such a Secret as a file documents the limitation in its `values.yaml` where it cannot close the gap.
- **What *can* be covered is the secret's `op://` path**, via a **separately named** `checksum/secret-ref` annotation over the rendered `OnePasswordItem`:

  ```yaml
  checksum/secret-ref: {{ include (print $.Template.BasePath "/<chart>.secret.yaml") . | sha256sum }}
  ```

  Repointing `secrets.<name>SecretRef` at a different vault item then takes effect instead of silently leaving the old credentials in the running pod. The separate name is deliberate: `checksum/config` promises "the config changed", `checksum/secret-ref` only "the config *source* changed" — merging them into one annotation would overstate the weaker guarantee. Reference implementations: `minecraft-server`, `homeassistant`.
- **`operator.1password.io/auto-restart` only works for Deployments — do not set it on a StatefulSet.** Verified against onepassword-operator **1.12.0** (`pkg/onepassword/secret_update_handler.go`): `restartWorkloadsWithUpdatedSecrets` enumerates exactly one workload type, `appsv1.DeploymentList`, and `getPodTemplate` accepts only `*appsv1.Deployment`. The RBAC role grants `statefulsets`, and v1.11.0 generalized the restart code (`restartWorkload`, pod-template stamping via `operator.1password.io/last-restarted`), but the PR that would add StatefulSets is still open — so the annotation on a StatefulSet is a silent no-op. Setting it there is **worse than not setting it**: it advertises a guarantee that does not exist. Affected charts (`matrix-synapse`, `samba`, `homeassistant`) instead document the manual `kubectl rollout restart statefulset <release>-<chart>-sfs`. Re-check this when the operator version is bumped; a Deployment-based chart may set the annotation.
- If a Deployment-based chart ever does set it, mind the precedence: the annotation on the **`OnePasswordItem`** is copied onto the Kubernetes Secret and read first, so a `false` there **overrides** a `true` on the workload — the opposite of what the operator's usage guide suggests. Lookup order is Secret (from the `OnePasswordItem`) → workload → namespace → the operator-global `AUTO_RESTART` env var. The trigger is the 1Password item's **version counter**, not its content, so a re-save with identical values still restarts.

### 10. Environment variables

- Every workload container offers an additive `env` value block, appended to the env entries the chart always sets.
- Entries are rendered through `tpl` (so values may contain Helm templating) and support the `value`, `secretKeyRef` and `configMapKeyRef` forms (pattern: `template-chart/templates/xxx.deployment.yaml`).
- **Additive means additive: an entry repeating a name the chart already sets does not replace it, and what the pair does depends on when it arrives.** At install both entries reach the pod and the later one — the user's — wins. On an *existing* release the same entry is lost: Kubernetes merges `env` by name, the pair collapses to the chart's own value, and `helm upgrade` still reports success. Measured on `urlaubsverwaltung` (helm 3.19.0, Kubernetes 1.35): `helm get manifest` shows the variable twice while the live Deployment shows it once, carrying the chart's value. The failure mode is silence, so a chart whose `NOTES.txt` tells operators to override one of its own variables has to say that the override only takes at install time — and that a green upgrade proves nothing, the value belongs read back off the Deployment.

### 11. Scaling

- Every Deployment/StatefulSet has a `replicas` value (default `1`, the values path per workload matches its section) that also accepts an explicit `0` for per-workload fine control.
- Every chart has a global `scaleDown` flag (default `false`): `scaleDown: true` takes precedence over all `replicas` values, renders every Deployment/StatefulSet with `replicas: 0` and suspends CronJobs. It **stops** the app but does not uninstall it — PVCs, Secrets, Services and Ingress stay in place; setting it back to `false` brings the workloads back up.
- Implemented via a per-chart `<chart>.replicas` helper in `_helpers.tpl` (reference in `template-chart`); the helper uses an explicit nil check (`kindIs "invalid"`) because Helm's `default` would swallow an explicit `0`.

### 12. Values that must not lie (#68, #93, #99, #215)

Every chart ships a **`values.schema.json`** with `additionalProperties: false` on **every chart-owned object level** — not just the top one. The gap this closes is a key that looks like configuration and does nothing: the pilot (#68) found three of them in one chart, one of them nested three levels deep and quietly leaving a game world unpinned. Objects that are passed **verbatim** into the pod spec stay open (probes, `securityContext.pod`/`.container`, `global`, free-form annotation maps): Kubernetes owns their schema, and restricting them would only reject fields that do not exist yet. The schema **adds to** `required()`, it does not replace it.

Reference implementation: `template-chart/values.schema.json` and `template-chart/templates/_helpers.tpl`.

**1. A value read outside its obvious template needs its own guard.** Before putting an Ingress behind `ingress.enabled`, check whether anything else reads `ingress.domain` — **in `templates/` and in `values.yaml`**, because `env` entries are rendered through `tpl` and hide such reads. If something does, that read needs its own `required()`; the gate then frees `clusterIssuer` but *not* `domain`. This happened in six charts, and matrix-synapse shows why it matters more than the count: its delegation nginx serves `ingress.domain` in the `/.well-known/matrix/{server,client}` endpoints through which **federation finds the homeserver**. Gating without the guard publishes

```
{"m.server": ":443"}     {"m.homeserver": {"base_url": "https://"}}
```

— rendered cleanly, pod green, federation broken. Check per chart and in both directions: in `calibre-web-automated` nothing outside the Ingress reads the domain, and there the gate frees both values.

**2. Probes, security contexts and resources go through the null-safe helper, never behind an `if`.** An override written without children is YAML null and erases the block: the container renders `securityContext: null` (unhardened, healthy, silent), a probe disappears, or `resources` loses its requests and computed limits. The `defaultedDict` helper defines the opposite semantics — an empty block means "chart defaults apply" — while an explicitly set value still wins, **including `false` and `0`** (hence the `kindIs "invalid"` check; `default` and `mergeOverwrite` both swallow zero values). Do **not** wrap these blocks in `{{- if }}`: a guard does not render a visible `null`, it removes the probe entirely, which is the same bug with no evidence left.

  The rule is about the **shape, not about those three block kinds**. `satisfactory` shipped 7.0.0 with `game` null-safe and its two neighbours not (Gitea #16): `--set server=null` aborted the render, and a single erased key was the quieter half — a nulled `server.gamePort` rendered `port:` and `nodePort:` empty into the Service and an empty `containerPort` into the StatefulSet, rejected by nothing until the API server saw it. Every chart-owned block a template dereferences belongs behind the helper, and a chart where only *some* of them do is worse than one where none do: whoever sees `game=null` fall back cleanly assumes `server=null` does too.

  **A deliberate exception is fine; an undocumented one is the bug.** `satisfactory.storage` is left un-defaulted on purpose — an erased size yields an invalid PVC that fails at apply time rather than a volume quietly sized by the chart — so `server: null` still renders a PVC without a size. That is a defensible trade and it is *not* the null-safety bug next to it; what makes it safe to leave standing is that the schema, `values.yaml` and the chart page all name it as an exception and point at the issue where it is argued (Gitea #39). Note also where the trade actually bites: only on a **new** install. For an existing release a fallback to the default size would fail too, because a PVC cannot shrink. Do not overturn a reasoned exception inside a bugfix patch — the patch then stops being one.

  **And `helm template` does not render `NOTES.txt`.** A value read there — `server` is read in four files in that chart — stays broken after a fix that looks green in every render, until someone runs a real `helm install`. `helm install --dry-run=client` is not the way around it either: it still wants a reachable API server (measured on helm v3.22.0). What works without a cluster: in a throwaway copy of the chart, wrap the verbatim `NOTES.txt` body in a `{{- define }}` and `include` it into a scratch ConfigMap, which `helm template` *does* render — same engine, same root context, only the sink differs.

**3. Do not hang liveness on an external dependency where a dependency-free path exists.** `zipline` deliberately probes `/` for liveness and `/api/healthcheck` only for readiness and startup, so a database outage cannot restart the pod. Where no such path exists — `outline` returns 500 on `/` when the database is down — all three probes may share the endpoint, but the reason belongs in a comment on the helper, or the next reader will "fix" the inconsistency.

  The other half of the same rule: readiness **must** hang on the dependency, and a separate path is not proof that it does. `urlaubsverwaltung` probed `/actuator/health/liveness` and `/actuator/health/readiness` for two years and still stayed 1/1 Ready through a total database outage (#218), because Spring Boot's `readiness` group contains `readinessState` **alone** — the split paths were right, the group content was empty of anything external. Whatever aggregates behind a probe path (Spring health groups, a `/healthz` a framework assembles for you) has to be read off the **running** endpoint, not off the path name; the chart names the members explicitly (`MANAGEMENT_ENDPOINT_HEALTH_GROUP_READINESS_INCLUDE=readinessState,db`) so the composition is in the template rather than in an upstream default.

**4. A fallback reproduces *this chart's* defaults, not the repo standard.** Five charts deviate from the hardening baseline on purpose. A "cleaned up" standard default is not tidying, it is an outage: `calibre-web-automated` must keep `readOnlyRootFilesystem: false`, because in read-only mode the image disables its PUID/PGID remapping and the runtime uid silently moves from 1000 to 911 — **making existing volume data inaccessible**. The same applies to non-standard values that look like mistakes: `satisfactory` keeps `limitFactor: 2` (that is what holds the memory limit at the published 8Gi) and `fsGroupChangePolicy: OnRootMismatch` (which avoids a recursive chown of multi-GB game files on every start).

**5. A probe default carries the probe's context, not just its timings.** Two different symptoms, both from real charts: `teamspeak-server` addresses its TCP port by the name `file-transfer` because the voice service is UDP and cannot be probed — a default without that name leaves the workload **with no working probe at all**. `patchmon` sends a `Host` header because the server answers **403** to any request whose Host is neither loopback nor a CORS_ORIGIN host — a default without it means the pod never becomes Ready. Port names, `Host` headers and `exec` commands belong in the fallback; where the context is dynamic, pass the root context in and rebuild it (patchmon derives the header from `ingress.domain`).

**6. A value that reads as the negation of the variable it feeds must actually be negated — and `not` cannot do it.** `satisfactory` shipped `game.seasonalEvents` straight into the image's `DISABLESEASONALEVENTS` (#215): the default `true` switched the events **off** in every install for the chart's whole life, while the schema described the same key as "true means events are enabled". The fix is the loud one — rename the key so it says what it does (`game.enableSeasonalEvents`) rather than silently inverting the template under existing releases, because the old key then fails schema validation instead of quietly meaning the opposite. Two mechanics come with it: Go's `not` treats **every non-empty string as true**, so `not "false"` is `false` and the string form these schemas deliberately accept flips the wrong way — compare explicitly (`eq (lower (printf "%v" $v)) "true"`) instead. And a value that cannot be read as either boolean belongs in a `fail`, not in an implicit branch: `enableSeasonalEvents: "yes"` must abort the render, not be quietly filed under "off". When such a rename lands, the new default is the one that **reproduces what the chart already rendered**; changing the meaning and the behaviour in the same release turns the loud fix back into a silent one.

**Two things about the mechanics that are easy to lose:**

- **`null` reaches the schema in one case and not the other.** For a key **with** a chart default, Helm's coalescing treats the `null` as a deletion and removes it *before* schema validation — the schema never sees it, and only the helper can catch it. For a key **without** a default (e.g. `resources.limits`), there is nothing to delete, the `null` survives into validation, and a strict `"type": "object"` aborts the render. That is why the helper **and** the widened `["object", "null"]` types are both needed: each covers a case the other cannot. Everything else stays strictly typed.
- **Validate every schema against the real values, not only against chart defaults.** Defaults are valid by construction, so they prove nothing. Render each chart against its bundle in `cluster-config/fleet-cd/` **and** against `helm get values` — the two differ more often than expected (four of ten bundles in one wave, always with the repo file being the worse one). This step caught a schema of mine that would have broken three live paperless releases, because all three write `tikaGotenberg.enabled` as the string `"true"` and the first draft demanded a boolean. Result per chart is a **list of rejected keys**, which is the cluster side's work order before the version is pulled up.

### 13. Everything else

- `icon:` is mandatory in every `Chart.yaml`. **Documented exception — freesailarr, the only chart without one**: the rule everywhere else is "the icon is this chart's one upstream's logo", and a chart bundling ten independently versioned projects has no such upstream — picking one of the ten would imply a "main app" the stack deliberately does not have. That is the whole criterion, and it applies to no other chart in the repo: a single-upstream chart without an icon is a missing icon, not an exception. The omission costs an INFO line in `helm lint --strict` (`icon is recommended`), which still exits 0.
- `helm lint --strict` must pass without findings.
- **Every chart ships a `templates/NOTES.txt`** (#43), `template-chart` included — so this is a requirement for a new chart, not a nice-to-have it can defer. No list of names here on purpose: a count goes stale the moment the next chart lands, which is exactly how the previous wording came to claim a number it never matched. Reference implementation: `template-chart/templates/NOTES.txt`, a placeholder-carrying template rather than finished prose, so a new chart adapts it instead of starting from an empty file. The bar it sets: print what an operator would otherwise have to look up in the templates (the rendered access URL, **which fields the 1Password item must carry**, the options actually active in this release, and the chart's known traps), conditional on the values really set. A `NOTES.txt` that only repeats the values is skimmed once and never read again. **No real domain anywhere** — the URL renders from `ingress.domain`, and where an example is unavoidable it is `example.com`. A `NOTES.txt` renders no Kubernetes object, so writing or reworking one is purely additive: a minor bump.
- CI: every installable chart has fixtures under `ci/<chart>/` (`test-values.yaml`, optionally `fixtures.yaml`/`fixtures.env.yaml`/`settings.env`) or a justified entry in `ci/excluded-charts.txt` — the install-test fails if both are missing.
### 14. Chart dependencies

Until `ytdlp-web-player` (#214) this section read "charts have no dependencies (`charts/` directories are empty)". That rule is gone, replaced by a bar rather than a ban — a dependency is **admissible, not free**, and the reason it stopped being a ban is worth keeping: the chart needed an oauth2-proxy in the data path in front of an application that ships no authentication at all, and proxy and app are only useful wired to each other.

**When a dependency earns its place.** All three, not two of three:

1. The dependent piece would otherwise be a second Helm release that only exists to serve this one, with the wiring between them living in neither chart.
2. Upstream is the right owner of it. We consume their chart as it comes: **we do not patch it, do not re-harden it, do not re-implement its values.** Where their defaults fall short of the guidelines above, that is **documented in our `values.yaml`**, not fixed by us — and a values-level fix stays available to whoever installs it.
3. It is **optional and off by default** (`condition:` in `Chart.yaml`), so the chart is complete without it and a default install renders none of its objects.

**What it costs, all of it visible before the next one is added:**

- **The subchart is invisible to everything downstream.** Its version is inside our packaged `.tgz`, so anything that watches Helm release versions — Fleet's `fleet.yaml` in `cluster-config` included — sees only *our* chart version. A new upstream release, security fix included, reaches a cluster **only** when we publish a new version of the outer chart. Nothing reports the gap. Renovate's built-in `helmv3` manager opens the PR (no `customManagers` entry needed — the repository URL and version sit together in one file) and `ci/renovate-bump-chart.sh` bumps the chart patch that ships it; that chain is the entire safety net. State this in a comment at the pinned version, not only in a review.
- **Every pipeline that touches the chart needs a network fetch first.** `helm lint`, `helm package`, `helm template` and `helm install` all exit 1 while a declared dependency is missing from `charts/`, so `ci/helm-dependencies.sh` runs before each of them (see CI/CD above). One of those call sites is the resource-quantity render test, which runs over **every** chart on **every** PR — a dependency-carrying chart can therefore turn a third-party Helm repository's bad day into a red pipeline on a PR that touched nothing related.
- **`charts/*.tgz` and `Chart.lock` are not committed** (`.gitignore` says why): the archive is a third-party binary nobody reviews in a diff, and a committed lock would arrive stale because Renovate rewrites `Chart.yaml` and cannot regenerate it — which is also why the pipelines run `helm dependency update` and not `helm dependency build`.
- **The repo's own mechanisms stop at the subchart boundary.** `checksum/config`, the 1Password auto-restart annotation and the `scaleDown` flag reach our templates only. A chart that renders a `OnePasswordItem` for its subchart documents the manual `kubectl rollout restart` that replaces the missing restart-on-change.

Two implementation notes that cost time otherwise: a values key containing a dash is unreachable as `.Values.oauth2-proxy` (that parses as a subtraction) and needs `index .Values "oauth2-proxy"`, while `condition:` in `Chart.yaml` splits on dots only and needs no escaping. And inside a subchart `.Chart.Name` is the **subchart's** name — a value templated into it (`config.configFile` in this case) must spell the parent chart out literally; only `.Release.Name` is shared.

Charts that need no dependency still have none, and `charts/` stays empty for all of them. `template-chart` remains dependency-free: the scaffold should not carry a `dependencies:` block a new chart has to remember to delete.