Patch K8s Custom Resource with #kubernetes/client-node - node.js

Question

I'm building Istio/K8s-based platform for controlling traffic routing with NodeJS. I need to be able to programmatically modify Custom Resources and I'd like to use the #kubernetes/node-client for that. I wasn't able to find the right API for accessing Custome Resources in docs and the repo. Am I missing something? Thx in adv.
EDIT: When using CustomObjectApi.patchNamespacedCustomObject function, I'm getting the following error back from K8s API:
message: 'the body of the request was in an unknown format - accepted media types include: application/json-patch+json, application/merge-patch+json, application/apply-patch+yaml', reason: 'UnsupportedMediaType', code: 415
My Code:
const k8sYamls = `${path.resolve(path.dirname(__filename), '..')}/k8sYamls`
const vServiceSpec = read(`${k8sYamls}/${service}/virtual-service.yaml`)
const kc = new k8s.KubeConfig()
kc.loadFromDefault()
const client = kc.makeApiClient(k8s.CustomObjectsApi)
const result = await client.patchNamespacedCustomObject(vServiceSpec.apiVersion.split('/')[0], vServiceSpec.apiVersion.split('/')[1], namespace, 'virtualservices', vServiceSpec.metadata.name, vServiceSpec)
virtual-service.yaml:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: message-service
spec:
hosts:
- message-service
http:
- name: 'production'
route:
- destination:
host: message-service
weight: 100
retries:
attempts: 3
perTryTimeout: 2s
retryOn: 5xx

Answer 1

I was using the wrong type for the body object in that method. I got it to work following this example.
const patch = [
{
"op": "replace",
"path":"/metadata/labels",
"value": {
"foo": "bar"
}
}
];
const options = { "headers": { "Content-type": k8s.PatchUtils.PATCH_FORMAT_JSON_PATCH}};
k8sApi.patchNamespacedPod(res.body.items[0].metadata.name, 'default', patch, undefined, undefined, undefined, undefined, options)
.then(() => { console.log("Patched.")})
.catch((err) => { console.log("Error: "); console.log(err)});

Answer 2

You can use the patchClusterCustomObject or patchNamespacedCustomObject methods, depending on whether the given object is namespaced or not, of the customObjectsApi.

Answer 3

Since the edit queue is full for the accepted answer I'm going to provide a working example and more thorough answer here using patchNamespacedCustomObject:
Here are some helpful links:
patchNamespacedCustomObject Docs
Your patch object should be an array of this object
The op field should be one of these
import * as k8s from "#kubernetes/client-node";
import { CustomObjectsApi, KubeConfig } from "#kubernetes/client-node";
export async function patchCustomResource(newValue: any) {
const kc: KubeConfig = new k8s.KubeConfig();
kc.loadFromDefault();
const custObjApi: CustomObjectsApi = kc.makeApiClient(k8s.CustomObjectsApi);
const objectName = 'your-object';
const options = { "headers": { "Content-type": k8s.PatchUtils.PATCH_FORMAT_JSON_PATCH}};
const group = 'your-group'; // found in the CRD
const version = 'v1'; // found in the CRD
const plural = 'object-plural'; // found in the CRD
const namespace = `your-namespace`;
// this will replace the value at `"/spec/path/to/modify"` with the contents of `newValue`
const patch = [{
"op": "replace",
"path":"/spec/path/to/modify",
"value": newValue
}];
try {
await custObjApi.patchNamespacedCustomObject(group, version, namespace, plural, objectName, patch, undefined, undefined, undefined, options);
console.log(`Successfully updated custom resource`);
} catch (error) {
const {body} = error;
console.log(body.message);
}
}
I urge anyone to spend some time on the CustomObjectsAPI docs to get more familiar with the available methods. The docs are dense but it's at least worth it to glance over method names.

Answer 4

After fighting through endless body-parsing errors using #kubernetes/node-client, I opted to install kubectl on my NodeJS workers and use shell.js to run it with.
My conclusion is that the #kubernetes/node-client is buggy when used with Istio Custom Resources, but didn't want to spend time debugging exactly what's wrong. I will post the Github Issue about it in their repo soon.