Merge pull request #24041 from awanlin/topic/nbs-kubernetes

Updated Kubernetes installation with new backend system examples

docs/features/kubernetes/installation.md

@@ -103,6 +103,31 @@ async function main() {
 That's it! The Kubernetes frontend and backend have now been added to your
 Backstage app.
 
+### New Backend System
+
+To get the Kubernetes plugin install using the New Backend System you will need to do the following:
+
+Run this command to add the package:
+
+```bash
+# From your Backstage root directory
+yarn --cwd packages/backend add @backstage/plugin-kubernetes-backend
+```
+
+Then add it to your backend `index.ts` file:
+
+```ts title="packages/backend/src/index.ts"
+const backend = createBackend();
+
+// Other plugins...
+
+/* highlight-add-start */
+backend.add(import('@backstage/plugin-kubernetes-backend/alpha'));
+/* highlight-add-end */
+
+backend.start();
+```
+
 ### Custom cluster discovery
 
 If either existing
@@ -174,6 +199,45 @@ export default async function createPlugin(
 }
 ```
 
+### New Backend System Custom cluster discovery
+
+To use Custom cluster discovery with the New Backend System you'll need to create a module and add it to your backend. Here's a very simplified example:
+
+```ts title="packages/backend/src/index.ts"
+import { createBackend } from '@backstage/backend-defaults';
+import { createBackendModule } from '@backstage/backend-plugin-api';
+import { Duration } from 'luxon';
+import { kubernetesClusterSupplierExtensionPoint } from '@backstage/plugin-kubernetes-node';
+import { CustomClustersSupplier } from './path/to/class';
+
+const backend = createBackend();
+
+export const kubernetesModuleCustomClusterDiscovery = createBackendModule({
+  pluginId: 'kubernetes',
+  moduleId: 'custom-cluster-discovery',
+  register(env) {
+    env.registerInit({
+      deps: {
+        kubernetes: kubernetesClusterSupplierExtensionPoint,
+      },
+      async init({ kubernetes }) {
+        kubernetes.addClusterSupplier(
+          CustomClustersSupplier.create(Duration.fromObject({ minutes: 60 })),
+        );
+      },
+    });
+  },
+});
+
+// Other plugins...
+backend.add(import('@backstage/plugin-kubernetes-backend/alpha'));
+backend.add(kubernetesModuleCustomClusterDiscovery);
+
+backend.start();
+```
+
+> Note: this example assumes the `CustomClustersSupplier` class is the same from the [previous example](#custom-cluster-discovery)
+
 ## Configuration
 
 After installing the plugins in the code, you'll need to then