chore: Describe RBAC rules, remove unnecessary rules

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+### Changed
+
+- Document Helm deployed RBAC permissions and remove unnecessary permissions ([#129]).
+
+[#129]: https://github.com/stackabletech/opensearch-operator/pull/129
+
 ## [26.3.0] - 2026-03-16
 
 ## [26.3.0-rc1] - 2026-03-16

deploy/helm/opensearch-operator/templates/roles.yaml → deploy/helm/opensearch-operator/templates/clusterrole-operator.yaml

@@ -1,30 +1,24 @@
+---
 apiVersion: rbac.authorization.k8s.io/v1
 kind: ClusterRole
 metadata:
   name: {{ include "operator.fullname" . }}-clusterrole
   labels:
   {{- include "operator.labels" . | nindent 4 }}
 rules:
-  - apiGroups:
-      - ""
-    resources:
-      - nodes
-    verbs:
-      - list
-      - watch
-  # For automatic cluster domain detection
+  # For automatic cluster domain detection.
   - apiGroups:
       - ""
     resources:
       - nodes/proxy
     verbs:
       - get
+  # Manage core workload resources created per OpenSearchCluster.
+  # Applied via SSA, tracked for orphan cleanup, and owned by the controller.
   - apiGroups:
       - ""
     resources:
       - configmaps
-      - endpoints
-      - pods
       - serviceaccounts
       - services
     verbs:
@@ -33,8 +27,9 @@ rules:
       - get
       - list
       - patch
-      - update
       - watch
+  # RoleBinding created per role group to bind the product ClusterRole to the workload
+  # ServiceAccount. Applied via SSA, tracked for orphan cleanup, and owned by the controller.
   - apiGroups:
       - rbac.authorization.k8s.io
     resources:
@@ -45,8 +40,18 @@ rules:
       - get
       - list
       - patch
-      - update
       - watch
+  # Required to bind the product ClusterRole to the per-rolegroup ServiceAccount.
+  - apiGroups:
+      - rbac.authorization.k8s.io
+    resources:
+      - clusterroles
+    verbs:
+      - bind
+    resourceNames:
+      - {{ include "operator.name" . }}-clusterrole
+  # StatefulSet created per role group. Applied via SSA, tracked for orphan cleanup, and
+  # owned by the controller.
   - apiGroups:
       - apps
     resources:
@@ -57,8 +62,9 @@ rules:
       - get
       - list
       - patch
-      - update
       - watch
+  # PodDisruptionBudget created per role group. Applied via SSA, tracked for orphan cleanup,
+  # and owned by the controller.
   - apiGroups:
       - policy
     resources:
@@ -69,92 +75,57 @@ rules:
       - get
       - list
       - patch
-      - update
       - watch
+  # Required for maintaining the CRDs within the operator (including the conversion webhook info).
+  # Also for the startup condition check before the controller can run.
   - apiGroups:
       - apiextensions.k8s.io
     resources:
       - customresourcedefinitions
     verbs:
-      - get
       # Required to maintain the CRD. The operator needs to do this, as it needs to enter e.g. it's
       # generated certificate in the conversion webhook.
       {{- if .Values.maintenance.customResourceDefinitions.maintain }}
       - create
       - patch
+      {{- end }}
       # Required for startup condition
       - list
       - watch
-      {{- end }}
+  # Listener created per role group for external access. Applied via SSA, tracked for orphan
+  # cleanup, and owned by the controller.
   - apiGroups:
       - listeners.stackable.tech
     resources:
       - listeners
     verbs:
+      - create
+      - delete
       - get
       - list
-      - watch
       - patch
-      - create
-      - delete
+      - watch
+  # Required to report reconciliation results and warnings back to the OpenSearchCluster object.
   - apiGroups:
       - events.k8s.io
     resources:
       - events
     verbs:
       - create
       - patch
+  # Primary CRD: watched by the controller and read during reconciliation.
   - apiGroups:
       - {{ include "operator.name" . }}.stackable.tech
     resources:
       - {{ include "operator.name" . }}clusters
     verbs:
       - get
       - list
-      - patch
       - watch
+  # Status subresource: updated at the end of every reconciliation.
   - apiGroups:
       - {{ include "operator.name" . }}.stackable.tech
     resources:
       - {{ include "operator.name" . }}clusters/status
     verbs:
       - patch
-  - apiGroups:
-      - rbac.authorization.k8s.io
-    resources:
-      - clusterroles
-    verbs:
-      - bind
-    resourceNames:
-      - {{ include "operator.name" . }}-clusterrole
----
-apiVersion: rbac.authorization.k8s.io/v1
-kind: ClusterRole
-metadata:
-  name: {{ include "operator.name" . }}-clusterrole
-  labels:
-  {{- include "operator.labels" . | nindent 4 }}
-rules:
-  - apiGroups:
-      - ""
-    resources:
-      - configmaps
-      - secrets
-      - serviceaccounts
-    verbs:
-      - get
-  - apiGroups:
-      - events.k8s.io
-    resources:
-      - events
-    verbs:
-      - create
-      - patch
-  - apiGroups:
-      - security.openshift.io
-    resources:
-      - securitycontextconstraints
-    resourceNames:
-      - nonroot-v2
-    verbs:
-      - use

deploy/helm/opensearch-operator/templates/clusterrole-product.yaml

@@ -0,0 +1,21 @@
+---
+# Product ClusterRole: bound (via per OpenSearchCluster RoleBinding) to the ServiceAccount that
+# OpenSearch workload pods run as.
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: {{ include "operator.name" . }}-clusterrole
+  labels:
+  {{- include "operator.labels" . | nindent 4 }}
+rules:
+{{ if .Capabilities.APIVersions.Has "security.openshift.io/v1" }}
+  # Required on OpenShift to allow the OpenSearch pods to run as a non-root user.
+  - apiGroups:
+      - security.openshift.io
+    resources:
+      - securitycontextconstraints
+    resourceNames:
+      - nonroot-v2
+    verbs:
+      - use
+{{ end }}