chore: reproduce unnecessary statefulset restarts

Author: sweb

tests/templates/kuttl/restarter-content-identical-write/00-patch-ns.yaml.j2

@@ -0,0 +1,9 @@
+{% if test_scenario['values']['openshift'] == 'true' %}
+# see https://github.com/stackabletech/issues/issues/566
+---
+apiVersion: kuttl.dev/v1beta1
+kind: TestStep
+commands:
+  - script: kubectl patch namespace $NAMESPACE -p '{"metadata":{"labels":{"pod-security.kubernetes.io/enforce":"privileged"}}}'
+    timeout: 120
+{% endif %}

tests/templates/kuttl/restarter-content-identical-write/10-assert.yaml

@@ -0,0 +1,14 @@
+---
+apiVersion: kuttl.dev/v1beta1
+kind: TestAssert
+timeout: 300
+---
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: test
+ generation: 1
+status:
+  readyReplicas: 2
+  replicas: 2
+  observedGeneration: 1

tests/templates/kuttl/restarter-content-identical-write/10-statefulset.yaml

@@ -0,0 +1,38 @@
+---
+# A minimal StatefulSet opted in to the restarter, mounting a ConfigMap.
+
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: test-config
+data:
+  foo: bar
+---
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: test
+  labels:
+    restarter.stackable.tech/enabled: "true"
+spec:
+  selector:
+    matchLabels:
+      app: test
+  serviceName: test
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: test
+    spec:
+      terminationGracePeriodSeconds: 1
+      containers:
+        - name: nginx
+          image: nginxinc/nginx-unprivileged:1.27
+          volumeMounts:
+            - name: config
+              mountPath: /config
+      volumes:
+        - name: config
+          configMap:
+            name: test-config

tests/templates/kuttl/restarter-content-identical-write/20-assert.yaml

@@ -0,0 +1,23 @@
+---
+apiVersion: kuttl.dev/v1beta1
+kind: TestAssert
+timeout: 30
+---
+# The ConfigMap content never changed.
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: test-config
+data:
+  foo: bar
+---
+# This should stay on generation 1
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: test
+  generation: 1
+status:
+  readyReplicas: 2
+  replicas: 2
+  observedGeneration: 1

tests/templates/kuttl/restarter-content-identical-write/20-content-identical-write.yaml

@@ -0,0 +1,19 @@
+---
+apiVersion: kuttl.dev/v1beta1
+kind: TestStep
+timeout: 120
+commands:
+  # Do a change that should (tm) not have an impact on a pod mounting/needing this cm.
+  - script: |
+      kubectl apply --server-side --field-manager=third-party-controller --force-conflicts -f - <<EOF
+      apiVersion: v1
+      kind: ConfigMap
+      metadata:
+        name: test-config
+        namespace: $NAMESPACE
+      data:
+        foo: bar
+      EOF
+
+  # Bit of time before the restart-controller can react, otherwise we directly pass.
+  - script: sleep 15

tests/test-definition.yaml

@@ -10,6 +10,9 @@ tests:
   - name: restarter-no-unneeded-restart
     dimensions:
       - openshift
+  - name: restarter-content-identical-write
+    dimensions:
+      - openshift
 suites:
   - name: nightly
   - name: openshift