new way of doin

helm-charts/dashy/charts/common/templates/lib/serviceAccount/_validation.tpl

@@ -0,0 +1,38 @@
+{{/* Service Account Primary Validation */}}
+{{/* Call this template:
+{{ include "tc.v1.common.lib.serviceAccount.primaryValidation" $ -}}
+*/}}
+
+{{- define "tc.v1.common.lib.serviceAccount.primaryValidation" -}}
+
+  {{/* Initialize values */}}
+  {{- $hasPrimary := false -}}
+  {{- $hasEnabled := false -}}
+
+  {{- range $name, $serviceAccount := .Values.serviceAccount -}}
+
+    {{/* If service account is enabled */}}
+    {{- if $serviceAccount.enabled -}}
+      {{- $hasEnabled = true -}}
+
+      {{/* And service account is primary */}}
+      {{- if and (hasKey $serviceAccount "primary") ($serviceAccount.primary) -}}
+
+        {{/* Fail if there is already a primary service account */}}
+        {{- if $hasPrimary -}}
+          {{- fail "Service Account - Only one service account can be primary" -}}
+        {{- end -}}
+
+        {{- $hasPrimary = true -}}
+
+      {{- end -}}
+
+    {{- end -}}
+  {{- end -}}
+
+  {{/* Require at least one primary service account, if any enabled */}}
+  {{- if and $hasEnabled (not $hasPrimary) -}}
+    {{- fail "Service Account - At least one enabled service account must be primary" -}}
+  {{- end -}}
+
+{{- end -}}