Added legacy serviceAccount name to clusterrolebinding.

Author: soenkeliebau

rust/operator-binary/src/hdfs_clusterrolebinding_nodes_controller.rs

@@ -72,12 +72,29 @@ pub async fn reconcile(
                 }
             }
         })
-        .map(|(meta, sa_name)| Subject {
-            kind: "ServiceAccount".to_string(),
-            name: sa_name,
-            namespace: meta.namespace.clone(),
-            ..Subject::default()
+        .map(|(meta, sa_name)| {
+            vec![
+                Subject {
+                    kind: "ServiceAccount".to_string(),
+                    name: sa_name,
+                    namespace: meta.namespace.clone(),
+                    ..Subject::default()
+                },
+                // This extra Serviceaccount is being written for legacy/compatibility purposes
+                // to ensure that running clusters don't lose access to anything during an upgrade
+                // of the Stackable operators, this code can be removed in later releases
+                // The value is hardcoded here, as we have removed access to the private fns that
+                // would have built it, since this is a known target though, and will be removed soon
+                // this should not be an issue.
+                Subject {
+                    kind: "ServiceAccount".to_string(),
+                    name: "hdfs-serviceaccount".to_string(),
+                    namespace: meta.namespace.clone(),
+                    ..Subject::default()
+                },
+            ]
         })
+        .flat_map(|vec| vec.into_iter())
         .collect();
 
     let patch = Patch::Apply(json!({