kubernetes-fluent-client
v3.3.7
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A @kubernetes/client-node fluent API wrapper that leverages K8s Server Side Apply.
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Kubernetes Fluent Client for Node
The Kubernetes Fluent Client for Node is a fluent API for the Kubernetes JavaScript Client with some additional logic for Server Side Apply, Watch with retry/signal control, and Field Selectors. In addition to providing a human-friendly API, it also provides a simple way to create and manage resources in the cluster and integrate with K8s in a type-safe way.
To install the Kubernetes Fluent Client, run the following command:
npm install kubernetes-fluent-client
See below for some example uses of the library.
import { K8s, kind } from "kubernetes-fluent-client";
// Let's create a random namespace to work in
const namespace = "my-namespace" + Math.floor(Math.random() * 1000);
// This will be called after the resources are created in the cluster
async function demo() {
// Now, we can use the fluent API to query for the resources we just created
// You can use watch to monitor resources in the cluster and react to changes
const watcher = K8s(kind.Pod).Watch((pod, phase) => {
console.log(`Pod ${pod.metadata?.name} is ${phase}`);
});
// This will run until the process is terminated or the watch is aborted
await watcher.start();
// Let's abort the watch after 5 seconds
setTimeout(watcher.close, 5 * 1000);
// Passing the name to Get() will return a single resource
const ns = await K8s(kind.Namespace).Get(namespace);
console.log(ns);
// This time we'll use the InNamespace() method to filter the results by namespace and name
const cm = await K8s(kind.ConfigMap).InNamespace(namespace).Get("my-configmap");
console.log(cm);
// If we don't pass a name to Get(), we'll get a list of resources as KubernetesListObject
// The matching resources will be in the items property
const pods = await K8s(kind.Pod).InNamespace(namespace).Get();
console.log(pods);
// Now let's delete the resources we created, you can pass the name to Delete() or the resource itself
await K8s(kind.Namespace).Delete(namespace);
// Let's use the field selector to find all the running pods in the cluster
const runningPods = await K8s(kind.Pod).WithField("status.phase", "Running").Get();
runningPods.items.forEach(pod => {
console.log(`${pod.metadata?.namespace}/${pod.metadata?.name} is running`);
});
// Get logs from a Deployment named "nginx" in the namespace
const logs = await K8s(kind.Deployment).InNamespace(namespace).Logs("nginx");
console.log(logs);
}
// Create a few resources to work with: Namespace, ConfigMap, and Pod
Promise.all([
// Create the namespace
K8s(kind.Namespace).Apply({
metadata: {
name: namespace,
},
}),
// Create the ConfigMap in the namespace
K8s(kind.ConfigMap).Apply({
metadata: {
name: "my-configmap",
namespace,
},
data: {
"my-key": "my-value",
},
}),
// Create the Pod in the namespace
K8s(kind.Pod).Apply({
metadata: {
name: "my-pod",
namespace,
},
spec: {
containers: [
{
name: "my-container",
image: "nginx",
},
],
},
}),
])
.then(demo)
.catch(err => {
console.error(err);
});
Generating TypeScript Definitions from CRDs
The Kubernetes Fluent Client can generate TypeScript definitions from Custom Resource Definitions (CRDs) using the generate
command. This command will generate TypeScript interfaces for the CRDs in the cluster and save them to a file.
To generate TypeScript definitions from CRDs, run the following command:
kubernetes-fluent-client crd /path/to/input.yaml /path/to/output/folder
If you have a CRD in a file named crd.yaml
and you want to generate TypeScript definitions in a folder named types
, you can run the following command:
kubernetes-fluent-client crd crd.yaml types
This will generate TypeScript interfaces for the CRD in the crd.yaml
file and save them to the types
folder.
By default, the generated TypeScript interfaces will be post-processed to make them more user-friendly. If you want to disable this post-processing, you can use the --noPost
flag:
kubernetes-fluent-client crd crd.yaml types --noPost
Community
To chat with other users & see some examples of the fluent client in active use, go to Kubernetes Slack and join #pepr
channel.