Installation

The Kubernetes feature is a plugin to Backstage, and it is exposed as a tab when viewing entities in the software catalog.

If you haven't setup Backstage already, read the Getting Started guide.

Adding the Kubernetes frontend plugin

The first step is to add the Kubernetes frontend plugin to your Backstage application.

From your Backstage root directory

yarn --cwd packages/app add @backstage/plugin-kubernetes

Once the package has been installed, you need to import the plugin in your app by adding the "Kubernetes" tab to the respective catalog pages.

packages/app/src/components/catalog/EntityPage.tsx

import { EntityKubernetesContent } from '@backstage/plugin-kubernetes';

// You can add the tab to any number of pages, the service page is shown as an
// example here
const serviceEntityPage = (
  <EntityLayout>
    {/* other tabs... */}
    <EntityLayout.Route path="/kubernetes" title="Kubernetes">
      <EntityKubernetesContent refreshIntervalMs={30000} />
    </EntityLayout.Route>
  </EntityLayout>
);

Notes:

• The optional refreshIntervalMs property on the EntityKubernetesContent defines the interval in which the content automatically refreshes, if not set this will default to 10 seconds.

That's it! But now, we need the Kubernetes Backend plugin for the frontend to work.

Adding Kubernetes Backend plugin

Navigate to packages/backend of your Backstage app, and install the @backstage/plugin-kubernetes-backend package.

From your Backstage root directory

yarn --cwd packages/backend add @backstage/plugin-kubernetes-backend

Create a file called kubernetes.ts inside packages/backend/src/plugins/ and add the following:

packages/backend/src/plugins/kubernetes.ts

import { KubernetesBuilder } from '@backstage/plugin-kubernetes-backend';
import { Router } from 'express';
import { PluginEnvironment } from '../types';
import { CatalogClient } from '@backstage/catalog-client';

export default async function createPlugin(
  env: PluginEnvironment,
): Promise<Router> {
  const catalogApi = new CatalogClient({ discoveryApi: env.discovery });
  const { router } = await KubernetesBuilder.createBuilder({
    logger: env.logger,
    config: env.config,
    catalogApi,
    discovery: env.discovery,
    permissions: env.permissions,
  }).build();
  return router;
}

And import the plugin to packages/backend/src/index.ts. There are three lines of code you'll need to add, and they should be added near similar code in your existing Backstage backend.

packages/backend/src/index.ts

// ..
import kubernetes from './plugins/kubernetes';

async function main() {
  // ...
  const kubernetesEnv = useHotMemoize(module, () => createEnv('kubernetes'));
  // ...
  apiRouter.use('/kubernetes', await kubernetes(kubernetesEnv));
}

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:

From your Backstage root directory

yarn --cwd packages/backend add @backstage/plugin-kubernetes-backend

Then add it to your backend index.ts file:

packages/backend/src/index.ts

const backend = createBackend();

// Other plugins...

backend.add(import('@backstage/plugin-kubernetes-backend'));

backend.start();

Custom cluster discovery

If either existing cluster locators don't work for your use-case, it is possible to implement a custom KubernetesClustersSupplier.

Change the following in packages/backend/src/plugins/kubernetes.ts:

packages/backend/src/plugins/kubernetes.ts

import {
  ClusterDetails,
  KubernetesBuilder,
  KubernetesClustersSupplier,
} from '@backstage/plugin-kubernetes-backend';
import { Router } from 'express';
import { PluginEnvironment } from '../types';
import { Duration } from 'luxon';

export class CustomClustersSupplier implements KubernetesClustersSupplier {
  constructor(private clusterDetails: ClusterDetails[] = []) {}

  static create(refreshInterval: Duration) {
    const clusterSupplier = new CustomClustersSupplier();
    // setup refresh, e.g. using a copy of https://github.com/backstage/backstage/blob/master/plugins/kubernetes-backend/src/service/runPeriodically.ts
    runPeriodically(
      () => clusterSupplier.refreshClusters(),
      refreshInterval.toMillis(),
    );
    return clusterSupplier;
  }

  async refreshClusters(): Promise<void> {
    this.clusterDetails = []; // fetch from somewhere
  }

  async getClusters(): Promise<ClusterDetails[]> {
    return this.clusterDetails;
  }
}

export default async function createPlugin(
  env: PluginEnvironment,
): Promise<Router> {

  const { router } = await KubernetesBuilder.createBuilder({
  const builder = await KubernetesBuilder.createBuilder({
     logger: env.logger,
     config: env.config,
  }).build();
  });
  builder.setClusterSupplier(
    CustomClustersSupplier.create(Duration.fromObject({ minutes: 60 })),
  );
  const { router } = await builder.build();

  // ..
  return router;
}

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:

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'));
backend.add(kubernetesModuleCustomClusterDiscovery);

backend.start();

Note

This example assumes the CustomClustersSupplier class is the same from the previous example

Configuration

After installing the plugins in the code, you'll need to then configure them.

Troubleshooting

After installing the plugins in the code, if the Kubernetes information is not showing up, you'll need to troubleshoot it.