fix(chart): make pre-upgrade-4-0-0 also delete the v3 Deployment and DaemonSets

chart/templates/migrations/pre-upgrade-3-20-0.yaml

@@ -14,7 +14,13 @@
     {{- $chartLabel := index $existingResource.metadata.labels "helm.sh/chart" }}
     {{- if $chartLabel }}
       {{- $prevVersion := trimPrefix "x509-certificate-exporter-" $chartLabel }}
-      {{- if semverCompare "<3.20.0" $prevVersion }}
+      {{/* Only fire when both the source release is pre-3.20.0 AND the
+           target release is still in the v3 line. Upgrades that cross
+           into v4+ are handled by pre-upgrade-4-0-0, which subsumes
+           the same Deployment/DaemonSet recreation alongside its own
+           Service migration. Without this gate the two hooks would run
+           in parallel and double-delete the same resources. */}}
+      {{- if and (semverCompare "<3.20.0" $prevVersion) (semverCompare "<4.0.0" .Chart.Version) }}
         {{- $needsMigration = true }}
       {{- end }}
     {{- end }}

chart/templates/migrations/pre-upgrade-4-0-0.yaml

@@ -1,25 +1,55 @@
 {{/*
 Pre-upgrade hook for v3 → v4 chart upgrades.
 
-Why: v4 flipped `service.headless` to `true` by default, which sets
-`clusterIP: None` on the Service. Kubernetes refuses to mutate a
-Service's clusterIP in place — `spec.clusterIPs[0]: may not change once
-set` — so an `helm upgrade` from a v3 release with an assigned ClusterIP
-to a v4 default install fails before any other reconciliation.
+Two unrelated immutable-field changes force a delete-and-recreate cycle:
 
-Strategy: if the existing Service carries a `helm.sh/chart` label
-matching a chart version <4.0.0, AND the new release will render a
-Service (`.Values.service.create` is true), delete it pre-upgrade so
-helm can recreate it from the new template — headless or otherwise,
-whichever the new values dictate.
+  1. Service.spec.clusterIP — v4 flipped `service.headless` to `true` by
+     default, which sets `clusterIP: None`. Kubernetes refuses to mutate
+     a Service's clusterIP in place (`spec.clusterIPs[0]: may not
+     change once set`).
+  2. Deployment.spec.selector and DaemonSet.spec.selector — v4 reworked
+     the per-component label set, which propagates to the immutable
+     selector. `helm upgrade` reports `field is immutable` on these.
+
+Strategy: if any v4-managed resource (Service, secrets-exporter
+Deployment, or any host-paths-exporter DaemonSet) still carries a
+`helm.sh/chart` label from a chart version <4.0.0, delete all of them
+pre-upgrade so helm can recreate them with the new schema. The pods
+they back are stateless: a few seconds of unavailability during the
+upgrade is the only side-effect.
+
+This hook also subsumes the responsibility of pre-upgrade-3-20-0 when
+the upgrade target is v4+ — see the version-gate inside that hook.
 */}}
 {{- $needsMigration := false }}
-{{- if and .Release.IsUpgrade .Values.service.create }}
+{{- if .Release.IsUpgrade }}
   {{- $ns := include "x509-certificate-exporter.namespace" . }}
-  {{- $svcName := include "x509-certificate-exporter.fullname" . }}
-  {{- $existingSvc := lookup "v1" "Service" $ns $svcName }}
-  {{- if $existingSvc }}
-    {{- $chartLabel := index $existingSvc.metadata.labels "helm.sh/chart" }}
+
+  {{/* Find any chart-managed resource still on chart <4.0.0. Probe the
+       Service first (always present unless the user disabled it), then
+       fall back to the Deployment, then any DaemonSet — covers users
+       who run with service.create=false. */}}
+  {{- $existingResource := dict }}
+  {{- if .Values.service.create }}
+    {{- $svc := lookup "v1" "Service" $ns (include "x509-certificate-exporter.fullname" .) }}
+    {{- if $svc }}{{ $existingResource = $svc }}{{ end }}
+  {{- end }}
+  {{- if not $existingResource }}
+    {{- $dep := lookup "apps/v1" "Deployment" $ns (include "x509-certificate-exporter.secretsExporterName" .) }}
+    {{- if $dep }}{{ $existingResource = $dep }}{{ end }}
+  {{- end }}
+  {{- if not $existingResource }}
+    {{- range $name, $_ := .Values.hostPathsExporter.daemonSets }}
+      {{- if not $existingResource }}
+        {{- $dsName := printf "%s-%s" (include "x509-certificate-exporter.fullname" $) $name }}
+        {{- $ds := lookup "apps/v1" "DaemonSet" $ns $dsName }}
+        {{- if $ds }}{{ $existingResource = $ds }}{{ end }}
+      {{- end }}
+    {{- end }}
+  {{- end }}
+
+  {{- if $existingResource }}
+    {{- $chartLabel := index $existingResource.metadata.labels "helm.sh/chart" }}
     {{- if $chartLabel }}
       {{- $prevVersion := trimPrefix "x509-certificate-exporter-" $chartLabel }}
       {{- if semverCompare "<4.0.0" $prevVersion }}
@@ -57,6 +87,9 @@ rules:
 - apiGroups: [""]
   resources: ["services"]
   verbs: ["get", "list", "delete"]
+- apiGroups: ["apps"]
+  resources: ["deployments", "daemonsets"]
+  verbs: ["get", "list", "delete"]
 ---
 apiVersion: rbac.authorization.k8s.io/v1
 kind: RoleBinding
@@ -125,5 +158,11 @@ spec:
         - --ignore-not-found=true
         - -n
         - {{ include "x509-certificate-exporter.namespace" . }}
+        {{- if .Values.service.create }}
         - service/{{ include "x509-certificate-exporter.fullname" . }}
+        {{- end }}
+        - deployment/{{ include "x509-certificate-exporter.secretsExporterName" . }}
+        {{- range $name, $_ := .Values.hostPathsExporter.daemonSets }}
+        - daemonset/{{ printf "%s-%s" (include "x509-certificate-exporter.fullname" $) $name }}
+        {{- end }}
 {{- end }}