docs: Extend the CRD documentation

deploy/helm/opensearch-operator/crds/crds.yaml

@@ -23,7 +23,7 @@ spec:
           description: Auto-generated derived type for OpenSearchClusterSpec via `CustomResource`
           properties:
             spec:
-              description: A OpenSearch cluster stacklet. This resource is managed by the Stackable operator for OpenSearch. Find more information on how to use it and the resources that the operator generates in the [operator documentation](https://docs.stackable.tech/home/nightly/opensearch/).
+              description: An OpenSearch cluster stacklet. This resource is managed by the Stackable operator for OpenSearch. Find more information on how to use it and the resources that the operator generates in the [operator documentation](https://docs.stackable.tech/home/nightly/opensearch/).
               properties:
                 clusterOperation:
                   default:
@@ -89,7 +89,7 @@ spec:
                       type: string
                   type: object
                 nodes:
-                  description: OpenSearch nodes
+                  description: This struct represents a role - e.g. HDFS datanodes or Trino workers. It has a key-value-map containing all the roleGroups that are part of this role. Additionally, there is a `config`, which is configurable at the role *and* roleGroup level. Everything at roleGroup level is merged on top of what is configured on role level. There is also a second form of config, which can only be configured at role level, the `roleConfig`. You can learn more about this in the [Roles and role group concept documentation](https://docs.stackable.tech/home/nightly/concepts/roles-and-role-groups).
                   properties:
                     cliOverrides:
                       additionalProperties:
@@ -138,6 +138,10 @@ spec:
                           nullable: true
                           type: string
                         nodeRoles:
+                          description: |-
+                            Roles of the OpenSearch node.
+
+                            Consult the [node roles documentation](https://docs.stackable.tech/home/nightly/opensearch/usage-guide/node-roles) for details.
                           items:
                             enum:
                               - cluster_manager
@@ -334,6 +338,10 @@ spec:
                                 nullable: true
                                 type: string
                               nodeRoles:
+                                description: |-
+                                  Roles of the OpenSearch node.
+
+                                  Consult the [node roles documentation](https://docs.stackable.tech/home/nightly/opensearch/usage-guide/node-roles) for details.
                                 items:
                                   enum:
                                     - cluster_manager

rust/operator-binary/src/crd/mod.rs

@@ -35,9 +35,9 @@ const DEFAULT_LISTENER_CLASS: &str = "cluster-internal";
 #[versioned(version(name = "v1alpha1"))]
 pub mod versioned {
 
-    /// A OpenSearch cluster stacklet. This resource is managed by the Stackable operator for OpenSearch.
-    /// Find more information on how to use it and the resources that the operator generates in the
-    /// [operator documentation](DOCS_BASE_URL_PLACEHOLDER/opensearch/).
+    /// An OpenSearch cluster stacklet. This resource is managed by the Stackable operator for
+    /// OpenSearch. Find more information on how to use it and the resources that the operator
+    /// generates in the [operator documentation](DOCS_BASE_URL_PLACEHOLDER/opensearch/).
     #[derive(Clone, CustomResource, Debug, Deserialize, JsonSchema, PartialEq, Serialize)]
     #[versioned(k8s(
         group = "opensearch.stackable.tech",
@@ -54,14 +54,14 @@ pub mod versioned {
     ))]
     #[serde(rename_all = "camelCase")]
     pub struct OpenSearchClusterSpec {
-        // no doc string - see ProductImage struct
+        // no doc - docs in ProductImage struct.
         pub image: ProductImage,
 
-        // no doc string - see ClusterOperation struct
+        // no doc - docs in ClusterOperation struct.
         #[serde(default)]
         pub cluster_operation: ClusterOperation,
 
-        /// OpenSearch nodes
+        // no doc - docs in Role struct.
         pub nodes:
             Role<OpenSearchConfigFragment, GenericRoleConfig, GenericProductSpecificCommonConfig>,
     }
@@ -130,6 +130,10 @@ pub mod versioned {
         #[fragment_attrs(serde(default))]
         pub graceful_shutdown_timeout: Duration,
 
+        /// Roles of the OpenSearch node.
+        ///
+        /// Consult the [node roles
+        /// documentation](DOCS_BASE_URL_PLACEHOLDER/opensearch/usage-guide/node-roles) for details.
         pub node_roles: NodeRoles,
 
         #[fragment_attrs(serde(default))]