kubernetes-client

kubernetes-client

Simplified Kubernetes API client for Node.js.

Installation

Install via npm:

npm i kubernetes-client --save

Initializing

kubernetes-client generates a Kubernetes API client at runtime based on a Swagger / OpenAPI specification. You can generate a client using the cluster's kubeconfig file and that cluster's API specification.

To create the config required to make a client, you can either:

let kubernetes-client configure automatically by trying the KUBECONFIG environment variable first, then ~/.kube/config, then an in-cluster service account, and lastly settling on a default proxy configuration:

const client = new Client({ version: '1.13' })

provide your own path to a file:

const { KubeConfig } = require('kubernetes-client')
const kubeconfig = new KubeConfig()
kubeconfig.loadFromFile('~/some/path')
const Request = require('kubernetes-client/backends/request')

const backend = new Request({ kubeconfig })
const client = new Client({ backend, version: '1.13' })

provide a configuration object from memory:

// Should match the kubeconfig file format exactly
const config = {
  apiVersion: 'v1',
  clusters: [],
  contexts: [],
  'current-context': '',
  kind: 'Config',
  users: []
}
const { KubeConfig } = require('kubernetes-client')
const kubeconfig = new KubeConfig()
kubeconfig.loadFromString(JSON.stringify(config))

const Request = require('kubernetes-client/backends/request')
const backend = new Request({ kubeconfig })
const client = new Client({ backend, version: '1.13' })

and you can also specify the context by setting it in the kubeconfig object:

kubeconfig.setCurrentContext('dev')

You can also elide the .version and pass an OpenAPI specification:

const spec = require('./swagger.json')
const client = new Client({ spec })

or load a specification dynamically from the kube-apiserver:

const client = new Client()
await client.loadSpec()

See Examples for more configuration examples.

Basic usage

kubernetes-client translates Path Item Objects [1] (e.g., /api/v1/namespaces) to object chains ending in HTTP methods (e.g., api.v1.namespaces.get).

So, to fetch all Namespaces:

const namespaces = await client.api.v1.namespaces.get()

kubernetes-client translates Path Templating [2] (e.g., /apis/apps/v1/namespaces/{namespace}/deployments) to function calls (e.g., apis.apps.v1.namespaces('default').deployments).

So, to create a new Deployment in the default Namespace:

const deploymentManifest = require('./nginx-deployment.json')
const create = await client.apis.apps.v1.namespaces('default').deployments.post({ body: deploymentManifest })

and then fetch your newly created Deployment:

const deployment = await client.apis.apps.v1.namespaces('default').deployments(deploymentManifest.metadata.name).get()

and finally, remove the Deployment:

await client.apis.apps.v1.namespaces('default').deployments(deploymentManifest.metadata.name).delete()

kubernetes-client supports .delete, .get, .patch, .post, and .put.

Documentation

kubernetes-client generates documentation for the included specifications:

• Kubernetes API v1.7
• Kubernetes API v1.8
• Kubernetes API v1.9
• Kubernetes API v1.10
• Kubernetes API v1.11
• Kubernetes API v1.12
• Kubernetes API v1.13

TypeScript

kubernetes-client includes a typings declartion file for Kubernetes API 1.13 and a complimentry Client1_13 class:

import * as Api from 'kubernetes-client';

const Client = Api.Client1_13;
const config = Api.config;
const client = new Client({ config: config.fromKubeconfig() });

When using TypeScript, kubernetes-client does not support dynamically generating a client via .loadSpec().

Examples

examples/ has snippets for using kubernetes-client:

• The basic usage example from above: basic.js
• Use error handling to simulate kubectl apply -f: apply-deploy.js
• Create a client from your kube-apiserver's swagger.json: client-from-apiserver-swagger.js
• Create a client from one of the included Swagger specifications: sync-client-version.js
• Using resource aliases supported by kubectl (e.g., .po vs .pods): convenience-properties.js
• Use watch endpoints to get a JSON stream of Deployment events: watch.js
• Extend the Kubernetes API and a client with a CustomerResourceDefinition: using-crds.js
• An extended CustomResourceDefinition example that implements a controller to "notify" on changes to Deployment objects: deployment-notifier.js
• A basic canary controller that removes Pods from a Service if they log an error: canary-controller.js
• Create a client using basic-auth: basic-auth.js
• Create a client using IAM authenticator and cmd auth (works with Amazon EKS): iam-auth.js
• Generate badges showing the status of your Deployments. Illustrates using the in-cluster config: kubernetes-badges
• Create a deployment, patch a change, and rollback to the original version: deployment-create-patch-rollback.js
• Access VerticalPodAutoscalers: vpas/
• Create a client using an in-cluster configuration: in-cluster-auth.js

Contributing

See the kubernetes-client Issues if you're interested in helping out; and look over the CONTRIBUTING.md before submitting new Issues and Pull Requests.

Testing

Run the unit tests:

npm test

The integration tests use the current-context in your kubeconfig file. Run the integration tests:

npm run test-integration

Run integration tests with the @kubernetes/client-node backend:

KUBERNETES_CLIENT_BACKEND=client-node npm run test-integration

References

• An Intuitive Node.js Client for the Kubernetes API
• Kubernetes Reference Documentation

License

MIT