chore: Describe RBAC rules, remove unnecessary rules (#810)

* chore: Describe RBAC rules, remove unnecessary rules

* chore: Update changelog

* fix: CRD permissions

- Add missing description
- Remove `get`, it is never used
- Make list/watch unconditional

* chore: Keep rbac.authorization.k8s.io rules together

* chore: Update changelog

* chore: Update descriptions on RBAC permissions

* chore: Remove unused permissions for the product ClusterRole

* chore(nix): Update crate hashes

* chore: Split clusterroles into separate files for operator and product

* chore: Correct roles mentioned

* Apply suggestions from code review

Co-authored-by: Techassi <git@techassi.dev>

* chore: Remove superfluous permissions from the product clusterrole

Co-authored-by: Nick <10092581+NickLarsenNZ@users.noreply.github.com>

---------

Co-authored-by: Techassi <git@techassi.dev>

Author: NickLarsenNZ

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 ([#810]).
+
+- [#810]: https://github.com/stackabletech/druid-operator/pull/810
+
 ## [26.3.0] - 2026-03-16
 
 ## [26.3.0-rc1] - 2026-03-16

Cargo.nix

@@ -6,73 +6,87 @@ metadata:
   labels:
   {{- include "operator.labels" . | nindent 4 }}
 rules:
-  - apiGroups:
-      - ""
-    resources:
-      - nodes
-    verbs:
-      - list
-      - watch
   # For automatic cluster domain detection
   - apiGroups:
       - ""
     resources:
       - nodes/proxy
     verbs:
       - get
+  # Manage core workload resources created per DruidCluster.
+  # All resources are applied via Server-Side Apply (create + patch) and tracked for
+  # orphan cleanup (list + delete).
   - apiGroups:
       - ""
     resources:
-      - pods
       - configmaps
-      - secrets
       - services
-      - endpoints
-      - serviceaccounts
     verbs:
       - create
       - delete
       - get
       - list
       - patch
-      - update
       - watch
+  # Shared internal authentication secret (cookie passphrase and internal client password).
+  # Orphan cleanup not needed (instead, Kubernetes GC via owner reference).
   - apiGroups:
-      - rbac.authorization.k8s.io
+      - ""
     resources:
-      - rolebindings
+      - secrets
     verbs:
       - create
       - delete
       - get
-      - list
       - patch
-      - update
-      - watch
+  # ServiceAccount created per DruidCluster for workload pod identity.
+  # Applied via SSA and tracked for orphan cleanup. Not watched by the controller.
   - apiGroups:
-      - apps
+      - ""
     resources:
-      - statefulsets
+      - serviceaccounts
     verbs:
+      - create
+      - delete
       - get
+      - list
+      - patch
+  # RoleBinding created per DruidCluster to bind the product ClusterRole to the workload
+  # ServiceAccount. Applied via SSA and tracked for orphan cleanup. Not watched by the controller.
+  - apiGroups:
+      - rbac.authorization.k8s.io
+    resources:
+      - rolebindings
+    verbs:
       - create
       - delete
+      - get
       - list
       - patch
-      - update
-      - watch
+  # Required to bind the product ClusterRole to the per-cluster 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:
-      - batch
+      - apps
     resources:
-      - jobs
+      - statefulsets
     verbs:
       - create
       - delete
       - get
       - list
       - patch
-      - update
       - watch
+  # PodDisruptionBudget created per role. Applied via SSA and tracked for orphan cleanup.
+  # Not watched by the controller.
   - apiGroups:
       - policy
     resources:
@@ -83,23 +97,24 @@ 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 and tracked for orphan
+  # cleanup.
   - apiGroups:
       - listeners.stackable.tech
     resources:
@@ -110,29 +125,31 @@ rules:
       - get
       - list
       - patch
-      - watch
+  # Required to report reconciliation results and warnings back to the DruidCluster object.
   - apiGroups:
       - events.k8s.io
     resources:
       - events
     verbs:
       - create
       - patch
+  # Primary CRD: watched by Controller::new() 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
+  # Read S3 connection and bucket configuration referenced in the DruidCluster spec.
   - apiGroups:
       - s3.stackable.tech
     resources:
@@ -142,6 +159,7 @@ rules:
       - get
       - list
       - watch
+  # Read authentication class configuration referenced in the DruidCluster spec.
   - apiGroups:
       - authentication.stackable.tech
     resources:
@@ -150,45 +168,3 @@ rules:
       - get
       - list
       - watch
-  - 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
-{{ if .Capabilities.APIVersions.Has "security.openshift.io/v1" }}
-  - apiGroups:
-      - security.openshift.io
-    resources:
-      - securitycontextconstraints
-    resourceNames:
-      - nonroot-v2
-    verbs:
-      - use
-{{ end }}

crate-hashes.json

@@ -0,0 +1,21 @@
+---
+# Product ClusterRole: bound (via per DruidCluster RoleBinding) to the ServiceAccount that Druid
+# workload pods (brokers, coordinators, historicals, middleManagers, routers) 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 Druid pods to run as a non-root user.
+  - apiGroups:
+      - security.openshift.io
+    resources:
+      - securitycontextconstraints
+    resourceNames:
+      - nonroot-v2
+    verbs:
+      - use
+{{ end }}