python kubernetes client example

python kubernetes client example

Here is a Python example using the Kubernetes client library (kubernetes-client-python) to interact with a Kubernetes cluster:

Prerequisites:

pip install kubernetes

Example code:

import os
from kubernetes import client, config
Load configuration from the default location (~/.kube/config)
config.load_kube_config()
Create a V1Pod object to represent our deployment
api_instance = client.AppsV1Api()
namespace = 'default'  # Replace with your desired namespace
pod_name = 'my-pod'  # Replace with your desired pod name
Set the environment variables for our pod
env_vars = [
{"name": "FOO", "value": "bar"},
{"name": "BAZ", "value": "qux"}
]
Create a container specification for our pod
container_spec = client.V1Container(
name="my-container",
image="nginx:latest",
env=env_vars,
ports=[client.V1ContainerPort(container_port=80)]
)
Set up the pod's metadata (name, namespace, labels)
pod_meta = client.V1ObjectMeta(name=pod_name, namespace=namespace, labels={"app": "my-app"})
Create a Pod object using our V1Pod and container spec
pod_obj = client.V1Pod(
api_version="v1",
kind="Pod",
metadata=pod_meta,
spec=client.V1PodSpec(containers=[container_spec])
)
try:
Call the Kubernetes API to create the pod
response = api_instance.create_namespaced_pod(namespace, pod_obj)
print(f"Created pod {pod_name} in namespace {namespace}: {response.status}")
except client.exceptions.ApiException as e:
print(f"Error creating pod: {e.status} {e.reason}")
finally:
Clean up (optional)
if not config.api_client.configuration.ssl_ca_certs:
config.api_client.configuration.ssl_ca_certs = None
print("Example complete!")

This example demonstrates the following:

Note:

Python kubernetes example

I'd be happy to help!

Here's an example of how you can use Python with Kubernetes:

Running a Python Application on Kubernetes

Let's say we have a simple Python web application that serves a "Hello World" page. We'll create a deployment for this application in Kubernetes.

First, create a requirements.txt file and add the necessary dependencies:

flask

Create a app.py file with the following code:

from flask import Flask
app = Flask(name)
@app.route('/')
def hello_world():
return 'Hello World!'
if name == 'main':
app.run(debug=True, port=80)

This is a simple Flask application that serves a "Hello World" page at the root URL (/).

Create a Kubernetes Deployment

Next, create a deployment.yaml file with the following content:

apiVersion: apps/v1
kind: Deployment
metadata:
name: python-app
spec:
replicas: 2
selector:
matchLabels:
app: python-app
template:
metadata:
labels:
app: python-app
spec:
containers:

name: python-app

image: python:3.9-slim
command: ["python"]
args: ["app.py"]
ports:

containerPort: 80

This YAML file defines a deployment named python-app with two replicas (i.e., two instances of the application). The template section specifies the container configuration, including the image (python:3.9-slim), command (python), and args (app.py). The ports section exposes port 80 from the container.

Apply the Deployment to Kubernetes

Run the following command to apply the deployment YAML file to your Kubernetes cluster:

kubectl apply -f deployment.yaml

This will create a new deployment named python-app with two replicas. You can verify that the deployment is running by using the kubectl get command:

kubectl get deployments

You should see an output like this:

NAME            DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   LAST UPDATED          AGE
python-app     2         2         0        True          1                           34s       35s

Verify the Application

To verify that the application is running, you can use the kubectl command to get the URL of the deployment:

kubectl get deployments python-app -o jsonpath='{.spec.template.spec.containers[0].ports[0].hostPort}'

This will give you the host port number (in this case, 32769). You can then use a tool like curl to access the application from outside the Kubernetes cluster:

curl http://localhost:32769/

You should see the "Hello World!" page returned in your browser.

Scaling and Updating the Deployment

Kubernetes makes it easy to scale and update deployments. You can use the kubectl scale command to increase or decrease the number of replicas:

kubectl scale deployment python-app --replicas=3

This will increase the number of replicas to 3. You can also use the kubectl apply command with a new YAML file that updates the existing deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
name: python-app
spec:
replicas: 2
selector:
matchLabels:
app: python-app
template:
metadata:
labels:
app: python-app
spec:
containers:

name: python-app

image: python:3.9-slim
command: ["python"]
args: ["app.py"]
ports:

containerPort: 80

This YAML file updates the existing deployment to have two replicas, and then applies it using the kubectl apply command.

That's a basic example of how you can use Python with Kubernetes!