feat(k8s): Helm chart for the whole stack on a single-node cluster (refs #25)

One chart whose values.yaml is a near-literal transcription of
infra/docker-compose.yml, rendered by three generic templates (Deployment, Job,
Service) over a `workloads` map — so the two stacks can be diffed by eye instead
of by archaeology, and adding a service is a values edit.

Platform-forced deviations, each commented where it appears:
- `args`, never `command`: compose replaces the image CMD, Kubernetes replaces the
  ENTRYPOINT. The chart fails to render on `command`, because the symptom (postgres
  refusing to run as root, Keycloak exec-ing `start-dev`) is nothing like the cause.
- The four Django services apply their own setup_configuration in the web pod
  rather than in a separate init Job: both scripts migrate, and without compose's
  depends_on they race the same database.
- OpenZaak and Objecten are addressed by service FQDN, because Django rejects a
  single-label host in a URL — the reason compose passes container IPs around.
- NodePorts, no ingress; databases are emptyDir until persistence.storageClass is
  set, so the stack comes up on a cluster with no CSI driver.

The upstream config inputs stay in the repo and become ConfigMaps via
infra/helm/seed-configmaps.sh — the Kubernetes sibling of infra/seed-config.sh —
so the compose stack and the chart cannot fork. infra/helm/registry.yaml runs an
in-cluster registry because Talos cannot side-load an image and a laptop-side one
needs a root-level firewall change.
This commit is contained in:
not
2026-09-04 17:51:21 +02:00
parent 916d671d49
commit 7a5840149c
12 changed files with 1124 additions and 1 deletions
@@ -0,0 +1,25 @@
{{ .Chart.Name }} {{ .Chart.Version }} deployed to namespace {{ .Release.Namespace }}.
Watch it converge (the upstream Django services migrate on first boot, so the
first bring-up takes a few minutes):
kubectl -n {{ .Release.Namespace }} get pods -w
kubectl -n {{ .Release.Namespace }} get jobs
Every bootstrap Job must reach Completions 1/1:
{{- range $name, $w := .Values.workloads }}
{{- if and (ne $w.enabled false) $w.job }}
- {{ $name }}
{{- end }}
{{- end }}
Open in a browser (add {{ .Values.host }} to /etc/hosts if you use a name):
{{- range $name, $port := .Values.nodePorts }}
{{- $w := index $.Values.workloads $name }}
{{- if ne $w.enabled false }}
{{ printf "%-16s http://%s:%v" $name $.Values.host $port }}
{{- end }}
{{- end }}
Test users are in docs/synthetic-data.md. If a pod is stuck in
ContainerCreating on a missing ConfigMap, run: make k8s-seed
@@ -0,0 +1,142 @@
{{/*
One pod spec for every workload, Deployment and Job alike. The chart is
values-driven on purpose: `.Values.workloads` is a near-literal transcription of
infra/docker-compose.yml, so the two stacks can be diffed by eye instead of by
archaeology. Adding a service is a values edit, not a template edit.
Called as: include "big.podspec" (dict "root" $ "name" $name "w" $w)
*/}}
{{- define "big.podspec" -}}
{{- $root := .root -}}
{{- $name := .name -}}
{{- $w := .w -}}
{{- with $root.Values.imagePullSecrets }}
imagePullSecrets:
{{- toYaml . | nindent 2 }}
{{- end }}
{{- with $w.waitFor }}
initContainers:
- name: wait-for-deps
image: {{ $root.Values.images.busybox }}
command:
- sh
- -c
- |
for t in {{ join " " . }}; do
echo "waiting for $t"
until nc -z "${t%:*}" "${t#*:}"; do sleep 2; done
done
{{- end }}
containers:
- name: {{ $name }}
image: {{ include "big.image" (dict "root" $root "name" $name "w" $w) }}
# Only this repo's images get the configured policy: their `dev` tag is mutable.
# Upstream tags are pinned, so IfNotPresent keeps them out of pod-template diffs —
# which matters because a changed template makes a Job unpatchable (immutable).
imagePullPolicy: {{ if $w.own }}{{ $root.Values.images.pullPolicy }}{{ else }}IfNotPresent{{ end }}
{{- if $w.command }}
{{- fail (printf "workload %s: use `args`, not `command` — compose's `command:` replaces CMD, but Kubernetes' `command:` replaces the image ENTRYPOINT (postgres would run as root, keycloak would exec `start-dev`)" $name) }}
{{- end }}
{{- with $w.args }}
args:
{{- toYaml . | nindent 6 }}
{{- end }}
{{- with $w.envFrom }}
envFrom:
{{- range . }}
- configMapRef:
# optional: an env group whose feature is disabled (e.g. otel) simply
# isn't rendered, and the pod must still start.
name: {{ printf "%s-env" . }}
optional: true
{{- end }}
{{- end }}
{{- with $w.env }}
env:
{{- include "big.env" (list $root .) | nindent 6 }}
{{- end }}
{{- with $w.ports }}
ports:
{{- range . }}
- name: {{ .name }}
containerPort: {{ .targetPort | default .port }}
{{- end }}
{{- end }}
{{- with $w.probe }}
readinessProbe:
{{- toYaml . | nindent 6 }}
{{- end }}
{{- with $w.resources }}
resources:
{{- toYaml . | nindent 6 }}
{{- end }}
{{- if or $w.files $w.data }}
volumeMounts:
{{- range $w.files }}
- name: {{ .configMap }}
mountPath: {{ .mountPath }}
{{- with .subPath }}
subPath: {{ . }}
{{- end }}
readOnly: true
{{- end }}
{{- with $w.data }}
- name: data
mountPath: {{ .mountPath }}
{{- end }}
{{- end }}
{{- if or $w.files $w.data }}
volumes:
{{- range $w.files }}
- name: {{ .configMap }}
configMap:
name: {{ .configMap }}
{{- with .defaultMode }}
defaultMode: {{ . }}
{{- end }}
{{- end }}
{{- with $w.data }}
- name: data
{{- if $root.Values.persistence.storageClass }}
persistentVolumeClaim:
claimName: {{ $name }}-data
{{- else }}
# No StorageClass configured: the databases are emptyDir, so the stack needs
# no CSI driver to come up. Data then lives as long as the pod does — see
# docs/runbooks/kubernetes-talos.md for switching on local-path.
emptyDir: {}
{{- end }}
{{- end }}
{{- end }}
{{- end -}}
{{/* Image ref: `own: true` workloads are built from this repo, everything else is upstream. */}}
{{- define "big.image" -}}
{{- $root := .root -}}
{{- $w := .w -}}
{{- if $w.own -}}
{{- $ref := printf "%s/%s:%s" $root.Values.images.repositoryPrefix .name $root.Values.images.tag -}}
{{- with $root.Values.images.registry }}{{ printf "%s/%s" . $ref }}{{ else }}{{ $ref }}{{ end }}
{{- else -}}
{{- $w.image -}}
{{- end -}}
{{- end -}}
{{/*
Env list from a map. Every value is run through `tpl`, so values.yaml can name
cluster-internal hosts ({{ .Release.Namespace }}) and the node address
({{ .Values.host }}) without the chart hard-coding either.
*/}}
{{- define "big.env" -}}
{{- $root := index . 0 -}}
{{- range $k, $v := index . 1 }}
- name: {{ $k }}
value: {{ tpl (toString $v) $root | quote }}
{{- end }}
{{- end -}}
{{- define "big.labels" -}}
app.kubernetes.io/name: {{ .name }}
app.kubernetes.io/instance: {{ .root.Release.Name }}
app.kubernetes.io/managed-by: Helm
{{- end -}}
@@ -0,0 +1,44 @@
{{- /*
Shared env blocks — the Kubernetes equivalent of the YAML anchors in
infra/docker-compose.yml (&oz-env, &nrc-env, &objecttypen-env, &objecten-env).
A workload picks them up with `envFrom`, so the web/celery/init variants of an
upstream image stay guaranteed-identical, and `kubectl get cm oz-env -o yaml`
shows what a pod actually got.
The *file* inputs (setup_configuration data.yaml, Keycloak realms, BPMN/DMN, the
seed scripts) are NOT here: they live in the repo and are turned into ConfigMaps
by infra/helm/seed-configmaps.sh, exactly as infra/seed-config.sh streams them
into the compose config volumes. Copying them into the chart would fork them.
*/ -}}
{{- range $group, $env := .Values.envGroups }}
---
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ $group }}-env
labels:
{{- include "big.labels" (dict "root" $ "name" (printf "%s-env" $group)) | nindent 4 }}
data:
{{- range $k, $v := $env }}
{{ $k }}: {{ tpl (toString $v) $ | quote }}
{{- end }}
{{- end }}
{{- /*
Portal OIDC config. The images bake config.json with the compose authority
(keycloak:8080), which a browser outside the cluster cannot resolve; these
ConfigMaps mount over it with the node address Keycloak's issuer is pinned to
(KC_HOSTNAME below), so the token the browser gets and the issuer the BFF
discovers are the same string. Same mechanism as infra/host-browser.yml.
*/ -}}
{{- range $realm := list "digid" "medewerker" }}
---
apiVersion: v1
kind: ConfigMap
metadata:
name: portal-config-{{ $realm }}
labels:
{{- include "big.labels" (dict "root" $ "name" (printf "portal-config-%s" $realm)) | nindent 4 }}
data:
config.json: |
{ "authority": "{{ printf "http://%s:%v" $.Values.host (index $.Values.nodePorts "keycloak") }}/realms/{{ $realm }}" }
{{- end }}
@@ -0,0 +1,39 @@
{{- range $name, $w := .Values.workloads }}
{{- if and (ne $w.enabled false) (not $w.job) }}
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: {{ $name }}
labels:
{{- include "big.labels" (dict "root" $ "name" $name) | nindent 4 }}
spec:
replicas: 1
# Recreate, not RollingUpdate: single node, ReadWriteOnce volumes, and nothing
# here is HA — a second pod would just fight the first for the disk.
strategy:
type: Recreate
selector:
matchLabels:
app.kubernetes.io/name: {{ $name }}
app.kubernetes.io/instance: {{ $.Release.Name }}
template:
metadata:
{{- /*
A ConfigMap mounted with subPath never picks up updates, so a portal whose
config.json content changed has to be rolled. Hashing only the values that
render it keeps the churn off the databases — an emptyDir database that is
recreated for no reason loses its data (see the runbook §6).
*/}}
{{- range $w.files }}
{{- if hasPrefix "portal-config-" .configMap }}
annotations:
checksum/portal-config: {{ printf "%s|%v" $.Values.host (index $.Values.nodePorts "keycloak") | sha256sum }}
{{- end }}
{{- end }}
labels:
{{- include "big.labels" (dict "root" $ "name" $name) | nindent 8 }}
spec:
{{- include "big.podspec" (dict "root" $ "name" $name "w" $w) | nindent 6 }}
{{- end }}
{{- end }}
@@ -0,0 +1,29 @@
{{- /*
The one-shot bootstrap containers from compose (oz-init, nrc-init, flowable-init,
the *-init setup_configuration runs, the zaaktype seed and the NRC abonnement)
become Jobs. All of them are idempotent, so ordering is not enforced with hooks:
each waits for the ports it needs (waitFor) and Kubernetes retries the rest.
A wiped database is re-seeded by `make k8s-reseed`.
*/ -}}
{{- range $name, $w := .Values.workloads }}
{{- if and (ne $w.enabled false) $w.job }}
---
apiVersion: batch/v1
kind: Job
metadata:
name: {{ $name }}
labels:
{{- include "big.labels" (dict "root" $ "name" $name) | nindent 4 }}
app.kubernetes.io/component: init
spec:
backoffLimit: 20
template:
metadata:
labels:
{{- include "big.labels" (dict "root" $ "name" $name) | nindent 8 }}
app.kubernetes.io/component: init
spec:
restartPolicy: OnFailure
{{- include "big.podspec" (dict "root" $ "name" $name "w" $w) | nindent 6 }}
{{- end }}
{{- end }}
@@ -0,0 +1,22 @@
{{- if .Values.persistence.storageClass }}
{{- range $name, $w := .Values.workloads }}
{{- if and (ne $w.enabled false) $w.data }}
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: {{ $name }}-data
labels:
{{- include "big.labels" (dict "root" $ "name" $name) | nindent 4 }}
# Keep the databases when the release is uninstalled; `make k8s-purge` drops them.
annotations:
helm.sh/resource-policy: keep
spec:
accessModes: [ReadWriteOnce]
storageClassName: {{ $.Values.persistence.storageClass }}
resources:
requests:
storage: {{ $w.data.size | default "2Gi" }}
{{- end }}
{{- end }}
{{- end }}
@@ -0,0 +1,35 @@
{{- /*
Service names are the compose service names, verbatim: the portals' Caddy
proxies to http://bff:8080 and the upstream setup_configuration files name
http://openzaak:8000 / http://nrc-web:8000, so in-cluster DNS has to answer to
exactly those names. Do not rename a workload without checking both.
.Values.nodePorts is the single place a port is published outside the cluster;
a workload listed there gets a NodePort on its first (only) port.
*/ -}}
{{- range $name, $w := .Values.workloads }}
{{- if and (ne $w.enabled false) $w.ports }}
{{- $nodePort := index $.Values.nodePorts $name }}
---
apiVersion: v1
kind: Service
metadata:
name: {{ $name }}
labels:
{{- include "big.labels" (dict "root" $ "name" $name) | nindent 4 }}
spec:
type: {{ if $nodePort }}NodePort{{ else }}ClusterIP{{ end }}
selector:
app.kubernetes.io/name: {{ $name }}
app.kubernetes.io/instance: {{ $.Release.Name }}
ports:
{{- range $i, $p := $w.ports }}
- name: {{ $p.name }}
port: {{ $p.port }}
targetPort: {{ $p.targetPort | default $p.port }}
{{- if and $nodePort (eq $i 0) }}
nodePort: {{ $nodePort }}
{{- end }}
{{- end }}
{{- end }}
{{- end }}