Custom Resources

  3 minute read  

Importing Custom Resources

The Kubernetes Fluent Client supports the creation of TypeScript typings directly from Kubernetes Custom Resource Definitions (CRDs). The files it generates can be directly incorporated into Pepr capabilities and provide a way to work with strongly-typed CRDs.

For example (below), Istio CRDs can be imported and used as though they were intrinsic Kubernetes resources.

Generating TypeScript Types from CRDs

Using the kubernetes-fluent-client to produce a new type looks like this:

npx kubernetes-fluent-client crd [source] [directory]

The crd command expects a [source], which can be a URL or local file containing the CustomResourceDefinition(s), and a [directory] where the generated code will live.

The following example creates types for the Istio CRDs:

user@workstation$  npx kubernetes-fluent-client crd https://raw.githubusercontent.com/istio/istio/master/manifests/charts/base/crds/crd-all.gen.yaml crds

Attempting to load https://raw.githubusercontent.com/istio/istio/master/manifests/charts/base/crds/crd-all.gen.yaml as a URL

- Generating extensions.istio.io/v1alpha1 types for WasmPlugin
- Generating networking.istio.io/v1alpha3 types for DestinationRule
- Generating networking.istio.io/v1beta1 types for DestinationRule
- Generating networking.istio.io/v1alpha3 types for EnvoyFilter
- Generating networking.istio.io/v1alpha3 types for Gateway
- Generating networking.istio.io/v1beta1 types for Gateway
- Generating networking.istio.io/v1beta1 types for ProxyConfig
- Generating networking.istio.io/v1alpha3 types for ServiceEntry
- Generating networking.istio.io/v1beta1 types for ServiceEntry
- Generating networking.istio.io/v1alpha3 types for Sidecar
- Generating networking.istio.io/v1beta1 types for Sidecar
- Generating networking.istio.io/v1alpha3 types for VirtualService
- Generating networking.istio.io/v1beta1 types for VirtualService
- Generating networking.istio.io/v1alpha3 types for WorkloadEntry
- Generating networking.istio.io/v1beta1 types for WorkloadEntry
- Generating networking.istio.io/v1alpha3 types for WorkloadGroup
- Generating networking.istio.io/v1beta1 types for WorkloadGroup
- Generating security.istio.io/v1 types for AuthorizationPolicy
- Generating security.istio.io/v1beta1 types for AuthorizationPolicy
- Generating security.istio.io/v1beta1 types for PeerAuthentication
- Generating security.istio.io/v1 types for RequestAuthentication
- Generating security.istio.io/v1beta1 types for RequestAuthentication
- Generating telemetry.istio.io/v1alpha1 types for Telemetry

✅ Generated 23 files in the istio directory

Observe that the kubernetes-fluent-client has produced the TypeScript types within the crds directory. These types can now be utilized in the Pepr module.

user@workstation$  cat crds/proxyconfig-v1beta1.ts
// This file is auto-generated by kubernetes-fluent-client, do not edit manually

import { GenericKind, RegisterKind } from "kubernetes-fluent-client";

export class ProxyConfig extends GenericKind {
    /**
     * Provides configuration for individual workloads. See more details at:
     * https://istio.io/docs/reference/config/networking/proxy-config.html
     */
    spec?:   Spec;
    status?: { [key: string]: any };
}

/**
 * Provides configuration for individual workloads. See more details at:
 * https://istio.io/docs/reference/config/networking/proxy-config.html
 */
export interface Spec {
    /**
     * The number of worker threads to run.
     */
    concurrency?: number;
    /**
     * Additional environment variables for the proxy.
     */
    environmentVariables?: { [key: string]: string };
    /**
     * Specifies the details of the proxy image.
     */
    image?: Image;
    /**
     * Optional.
     */
    selector?: Selector;
}

/**
 * Specifies the details of the proxy image.
 */
export interface Image {
    /**
     * The image type of the image.
     */
    imageType?: string;
}

/**
 * Optional.
 */
export interface Selector {
    /**
     * One or more labels that indicate a specific set of pods/VMs on which a policy should be
     * applied.
     */
    matchLabels?: { [key: string]: string };
}

RegisterKind(ProxyConfig, {
  group: "networking.istio.io",
  version: "v1beta1",
  kind: "ProxyConfig",
});

Using new types

The generated types can be imported into Pepr directly, there is no additional logic needed to make them to work.

import { Capability, K8s, Log, a, kind } from "pepr";

import { Gateway } from "../crds/gateway-v1beta1";
import {
  PurpleDestination,
  VirtualService,
} from "../crds/virtualservice-v1beta1";

export const IstioVirtualService = new Capability({
  name: "istio-virtual-service",
  description: "Generate Istio VirtualService resources",
});

// Use the 'When' function to create a new action
const { When, Store } = IstioVirtualService;

// Define the configuration keys
enum config {
  Gateway = "uds/istio-gateway",
  Host = "uds/istio-host",
  Port = "uds/istio-port",
  Domain = "uds/istio-domain",
}

// Define the valid gateway names
const validGateway = ["admin", "tenant", "passthrough"];

// Watch Gateways to get the HTTPS domain for each gateway
When(Gateway)
  .IsCreatedOrUpdated()
  .WithLabel(config.Domain)
  .Watch(vs => {
    // Store the domain for the gateway
    Store.setItem(vs.metadata.name, vs.metadata.labels[config.Domain]);
  });