Add per-workload replicas values and a chart-global scaleDown flag

Every Deployment/StatefulSet now takes its replica count from a replicas
value (default 1, explicit 0 allowed) via a new per-chart <chart>.replicas
helper; the helper uses a kindIs "invalid" nil check so an explicit 0 is
not swallowed by Helm's default function. A chart-global scaleDown flag
(default false) takes precedence: it renders every workload with
replicas: 0 and suspends the paperless-ngx consume CronJob, stopping the
app without uninstalling it (PVCs, Secrets, Services and Ingress remain).

Defaults leave the rendered manifests byte-identical to main, so all
published charts get a minor version bump; the template-chart carries the
reference helper implementation and stays unversioned.

Fixes #25

urlaubsverwaltung/Chart.yaml

@@ -3,5 +3,5 @@ name: urlaubsverwaltung
 description: A Helm chart to deploy urlaubsverwaltung on Kubernetes
 type: application
 
-version: 4.0.0+up6.5.0
+version: 4.1.0+up6.5.0
 appVersion: 6.5.0

urlaubsverwaltung/templates/_helpers.tpl

@@ -83,3 +83,34 @@ results are printed without a decimal point.
 {{- printf "%v%s" $product $suffix -}}
 {{- end -}}
 {{- end -}}
+
+{{/*
+Render the replica count for a Deployment/StatefulSet.
+
+Input: dict
+  "scaleDown"  the chart-global .Values.scaleDown flag (may be nil)
+  "replicas"   the workload's replicas value (may be nil)
+
+Rules (issue #25):
+  - scaleDown: true takes precedence and always yields 0.
+  - otherwise an explicitly set replicas value is used as given, including an
+    explicit 0 — Helm's "default" would swallow 0, hence the explicit
+    kindIs "invalid" nil check.
+  - a missing replicas value defaults to 1.
+
+Usage (the values path to the workload's replicas varies per chart):
+  replicas: {{ include "urlaubsverwaltung.replicas" (dict "scaleDown" .Values.scaleDown "replicas" .Values.<app>.replicas) }}
+
+NOTE: like the resources helper above, this is duplicated into every chart's
+templates/_helpers.tpl with the chart's name as define prefix. This file in
+template-chart is the reference implementation.
+*/}}
+{{- define "urlaubsverwaltung.replicas" -}}
+{{- if .scaleDown -}}
+0
+{{- else if not (kindIs "invalid" .replicas) -}}
+{{- .replicas -}}
+{{- else -}}
+1
+{{- end -}}
+{{- end -}}

urlaubsverwaltung/templates/urlaubsverwaltung.deployment.yaml

@@ -5,7 +5,7 @@ metadata:
   labels:
     app: {{ .Chart.Name }}-{{ .Release.Name }}
 spec:
-  replicas: 1
+  replicas: {{ include "urlaubsverwaltung.replicas" (dict "scaleDown" .Values.scaleDown "replicas" .Values.urlaubsverwaltung.replicas) }}
   selector:
     matchLabels:
       app: {{ .Chart.Name }}-{{ .Release.Name }}-uv-deployment

urlaubsverwaltung/values.yaml

@@ -1,3 +1,9 @@
+# Scale the whole chart down without uninstalling it: scaleDown: true renders
+# every Deployment/StatefulSet with replicas: 0 (and suspends CronJobs) and
+# takes precedence over any per-workload replicas value. PVCs, Secrets and
+# Services stay in place; scaleDown: false brings the workloads back up.
+scaleDown: false
+
 secrets:
   databaseSecretRef: null
   oidcSecretRef: null
@@ -7,6 +13,9 @@ ingress:
   domain: null
 
 urlaubsverwaltung:
+  # Replica count for this workload; 0 is allowed and scales it down.
+  # The chart-global scaleDown flag takes precedence.
+  replicas: 1
   # The official image is built with Cloud Native Buildpacks and runs as the
   # non-root cnb user (uid 1002, gid 1001). /tmp is a writable emptyDir for
   # the JVM's temp/work files.
@@ -30,4 +39,4 @@ urlaubsverwaltung:
     requests:
       cpu: 0.1
       memory: 768Mi
-      ephemeralStorage: 10Mi
+      ephemeralStorage: 10Mi