Pod Operations

Execute commands, attach to containers, forward ports, copy files, and stream logs.

Prerequisites

Install the client: npm install @kubernetes/client-node. These examples require a valid kubeconfig (default: ~/.kube/config) or in-cluster service account. Run with Node.js 18+.

Exec into a Pod

examples/typescript/exec/exec-example.ts

import * as k8s from '@kubernetes/client-node';
import stream from 'node:stream';

const command = process.argv[2];

const kc = new k8s.KubeConfig();
kc.loadFromDefault();

const exec = new k8s.Exec(kc);

const namespace = 'default';
const pod = 'nginx-4217019353-9gl4s';
const container = 'nginx';

exec.exec(
    namespace,
    pod,
    container,
    command,
    process.stdout as stream.Writable,
    process.stderr as stream.Writable,
    process.stdin as stream.Readable,
    true /* tty */,
    (status: k8s.V1Status) => {
        console.log('Exited with status:');
        console.log(JSON.stringify(status, null, 2));
    },
);

Related: KubeConfig · Exec

Attach to a Container

examples/typescript/attach/attach-example.ts

import * as k8s from '@kubernetes/client-node';

const kc = new k8s.KubeConfig();
kc.loadFromDefault();

const attach = new k8s.Attach(kc);

const namespace = 'default';
const pod = 'nginx-4217019353-9gl4s';
const container = 'nginx';

await attach.attach(
    namespace,
    pod,
    container,
    process.stdout,
    process.stderr,
    null /* stdin */,
    false /* tty */,
);

Related: KubeConfig · Attach

Port Forward (Pod)

examples/typescript/port-forward/port-forward.ts

import * as k8s from '@kubernetes/client-node';
import net from 'node:net';

const kc = new k8s.KubeConfig();
kc.loadFromDefault();

const forward = new k8s.PortForward(kc);

const namespace = 'default';
const pod = 'demo';
const port = 8080;

// This simple server just forwards traffic from itself to a service running in kubernetes
// -> localhost:8080 -> port-forward-tunnel -> kubernetes-pod
// This is basically equivalent to 'kubectl port-forward ...' but in TypeScript.
const server = net.createServer((socket) => {
    forward.portForward(namespace, pod, [port], socket, null, socket);
});

server.listen(port, '127.0.0.1');

Related: KubeConfig · PortForward

Port Forward (Deployment)

examples/typescript/port-forward/port-forward-deployment.ts

import * as k8s from '@kubernetes/client-node';
import net from 'node:net';

const kc = new k8s.KubeConfig();
kc.loadFromDefault();

const forward = new k8s.PortForward(kc);

const namespace = process.argv[2] ?? 'default';
const deploymentName = process.argv[3] ?? 'demo-deployment';
const localPort = parseInt(process.argv[4] ?? '8080', 10);
const remotePort = parseInt(process.argv[5] ?? '8080', 10);

// This creates a local server that forwards traffic to a deployment in Kubernetes
// by resolving the deployment to its first ready pod and port-forwarding to that pod.
// Usage: node port-forward-deployment.ts [namespace] [deploymentName] [localPort] [remotePort]
// Example: node port-forward-deployment.ts default my-app 8080 3000
// This is equivalent to: kubectl port-forward deployment/my-app 8080:3000 -n default

const server = net.createServer(async (socket) => {
    try {
        await forward.portForwardDeployment(namespace, deploymentName, [remotePort], socket, null, socket);
    } catch (error) {
        console.error(
            `Error port-forwarding to deployment ${namespace}/${deploymentName}:`,
            (error as Error).message,
        );
        socket.destroy();
    }
});

server.listen(localPort, '127.0.0.1', () => {
    console.log(`Port forward server listening on http://127.0.0.1:${localPort}`);
    console.log(`Forwarding to deployment: ${namespace}/${deploymentName}:${remotePort}`);
    console.log(`Press Ctrl+C to stop`);
});

server.on('error', (error: NodeJS.ErrnoException) => {
    console.error('Server error:', error);
});

process.on('SIGINT', () => {
    console.log('\nShutting down port-forward server...');
    server.close();
    process.exit(0);
});

Related: KubeConfig · PortForward

Port Forward (Service)

examples/typescript/port-forward/port-forward-service.ts

import * as k8s from '@kubernetes/client-node';
import net from 'node:net';

const kc = new k8s.KubeConfig();
kc.loadFromDefault();

const forward = new k8s.PortForward(kc);

const namespace = process.argv[2] ?? 'default';
const serviceName = process.argv[3] ?? 'demo-service';
const localPort = parseInt(process.argv[4] ?? '8080', 10);
const remotePort = parseInt(process.argv[5] ?? '8080', 10);

// This creates a local server that forwards traffic to a service in Kubernetes
// by resolving the service to its first ready pod and port-forwarding to that pod.
// Usage: node port-forward-service.ts [namespace] [serviceName] [localPort] [remotePort]
// Example: node port-forward-service.ts default my-service 8080 80
// This is equivalent to: kubectl port-forward svc/my-service 8080:80 -n default

const server = net.createServer(async (socket) => {
    try {
        await forward.portForwardService(namespace, serviceName, [remotePort], socket, null, socket);
    } catch (error) {
        console.error(`Error port-forwarding to service ${namespace}/${serviceName}:`, error.message);
        socket.destroy();
    }
});

server.listen(localPort, '127.0.0.1', () => {
    console.log(`Port forward server listening on http://127.0.0.1:${localPort}`);
    console.log(`Forwarding to service: ${namespace}/${serviceName}:${remotePort}`);
    console.log(`Press Ctrl+C to stop`);
});

server.on('error', (error: NodeJS.ErrnoException) => {
    console.error('Server error:', error);
});

process.on('SIGINT', () => {
    console.log('\nShutting down port-forward server...');
    server.close();
    process.exit(0);
});

Related: KubeConfig · PortForward

Copy Files

examples/typescript/cp/cp-example.ts

import * as k8s from '@kubernetes/client-node';

const kc = new k8s.KubeConfig();
kc.loadFromDefault();

const cp = new k8s.Cp(kc);

const namespace = 'default';
const pod = 'nginx-4217019353-9gl4s';
const container = 'nginx';
const srcPath = './test.txt';
const targetPath = '/tmp';

await cp.cpFromPod(namespace, pod, container, srcPath, targetPath);

Related: KubeConfig · Cp

Follow Logs

examples/follow-logs.js

import * as k8s from '@kubernetes/client-node';
import stream from 'node:stream';

const kc = new k8s.KubeConfig();
kc.loadFromDefault();

const log = new k8s.Log(kc);
const logStream = new stream.PassThrough();
const namespace = 'default';
const pod = 'pod1';
const container = 'container1';

logStream.on('data', (chunk) => {
    // use write rather than console.log to prevent double line feed
    process.stdout.write(chunk);
});

try {
    const req = await log.log(namespace, pod, container, logStream, {
        follow: true,
        tailLines: 50,
        pretty: false,
        timestamps: false,
    });

    // disconnects after 5 seconds
    setTimeout(() => {
        // Note: You might have to install AbortController if you are using Node version < 15.0.0
        req.abort();
    }, 5000);
} catch (err) {
    console.error(err);
}

Related: KubeConfig · Log