kr8s

A simple, extensible Python client library for Kubernetes that feels familiar for folks who already know how to use kubectl.

Highlights

• API inspired by kubectl for a shallow learning curve.
• Sensible defaults to reduce boiler plate.
• No swagger generated code, human readable code only.
• Has both a standard and an async API that can be used with asyncio and trio.
• Client caching to reduce passing API objects around.
• Batteries included by providing useful utilities and methods inspired by kubectl.

Quickstart

Installation

$ pip install kr8s

Examples

> [!TIP] > See the Examples Documentation for a full set of examples including asyncio examples.

List Nodes

Print out all of the node names in the cluster.

import kr8s

for node in kr8s.get("nodes"):
    print(node.name)

Create a Pod

Create a new Pod.

from kr8s.objects import Pod

pod = Pod({
        "apiVersion": "v1",
        "kind": "Pod",
        "metadata": {
            "name": "my-pod",
        },
        "spec": {
            "containers": [{"name": "pause", "image": "gcr.io/google_containers/pause",}]
        },
    })

pod.create()

Scale a Deployment

Scale the Deployment metrics-server in the Namespace kube-system to 1 replica.

from kr8s.objects import Deployment

deploy = Deployment.get("metrics-server", namespace="kube-system")
deploy.scale(1)

List Pods by label selector

Get all Pods from all Namespaces matching a label selector.

import kr8s

selector = {'component': 'kube-scheduler'}

for pod in kr8s.get("pods", namespace=kr8s.ALL, label_selector=selector):
    print(pod.namespace, pod.name)

Add a label to a Pod

Add the label foo with the value bar to an existing Pod.

from kr8s.objects import Pod

pod = Pod("kube-apiserver", namespace="kube-system")
pod.label({"foo": "bar"})

Generate a Pod

Generate a simple Pod with a couple of keyword arguments.

from kr8s.objects import Pod

pod = Pod.gen(name="example-1", image="nginx:latest")
pod.create()

Cordon a Node

Cordon a Node to mark it as unschedulable.

from kr8s.objects import Node

node = Node("k8s-node-1")

node.cordon()

Pod Exec

Exec a command in a Pod.

from kr8s.objects import Pod

pod = Pod.get("my-pod")

command = pod.exec(["uptime"])
print(command.stdout.decode())
# 13:49:05 up 23:03,  0 users,  load average: 0.66, 0.87, 0.85

Port forward a Pod

Open a port forward to a Pod as a background task/thread.

from kr8s.objects import Pod

pod = Pod.get("my-pod")
pf = pod.portforward(remote_port=1234, local_port=5678)

# Starts the port forward in a background thread
pf.start()

# Your other code goes here

# Optionally stop the port forward thread (it will exit with Python anyway)
pf.stop()

> [!TIP] > See the Examples Documentation for a full set of examples including asyncio examples.