A cluster is a set of nodes (physical or virtual machines) running Kubernetes agents, managed by the control plane. Kubernetes v1.33 supports clusters with up to 5,000 nodes. More specifically, Kubernetes is designed to accommodate configurations that meet all of the following criteria: No more than 110 pods per node No more than 5,000 nodes No more than 150,000 total pods No more than 300,000 total containers You can scale your cluster by adding or removing nodes.

Resources that Kubernetes provides for configuring Pods.

FEATURE STATE: Kubernetes v1.25 [stable] This page provides an overview of ephemeral containers: a special type of container that runs temporarily in an existing Pod to accomplish user-initiated actions such as troubleshooting. You use ephemeral containers to inspect services rather than to build applications. Understanding ephemeral containers Pods are the fundamental building block of Kubernetes applications. Since Pods are intended to be disposable and replaceable, you cannot add a container to a Pod once it has been created.

Production-Grade Container Orchestration

This page shows how to use Weave Net for NetworkPolicy. Before you begin You need to have a Kubernetes cluster. Follow the kubeadm getting started guide to bootstrap one. Install the Weave Net addon Follow the Integrating Kubernetes via the Addon guide. The Weave Net addon for Kubernetes comes with a Network Policy Controller that automatically monitors Kubernetes for any NetworkPolicy annotations on all namespaces and configures iptables rules to allow or block traffic as directed by the policies.

Kubernetes provides a certificates.k8s.io API, which lets you provision TLS certificates signed by a Certificate Authority (CA) that you control. These CA and certificates can be used by your workloads to establish trust. certificates.k8s.io API uses a protocol that is similar to the ACME draft. Note:Certificates created using the certificates.k8s.io API are signed by a dedicated CA. It is possible to configure your cluster to use the cluster root CA for this purpose, but you should never rely on this.

This guide demonstrates how to access the Kubernetes API from within a pod. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:

FEATURE STATE: Kubernetes v1.30 [stable] This page provides an overview of Validating Admission Policy. What is Validating Admission Policy? Validating admission policies offer a declarative, in-process alternative to validating admission webhooks. Validating admission policies use the Common Expression Language (CEL) to declare the validation rules of a policy. Validation admission policies are highly configurable, enabling policy authors to define policies that can be parameterized and scoped to resources as needed by cluster administrators.

This page provides a step-by-step example of updating configuration within a Pod via a ConfigMap and builds upon the Configure a Pod to Use a ConfigMap task. At the end of this tutorial, you will understand how to change the configuration for a running application. This tutorial uses the alpine and nginx images as examples. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster.

A WebHook is an HTTP callback: an HTTP POST that occurs when something happens; a simple event-notification via HTTP POST. A web application implementing WebHooks will POST a message to a URL when certain things happen. When specified, mode Webhook causes Kubernetes to query an outside REST service when determining user privileges. Configuration File Format Mode Webhook requires a file for HTTP configuration, specify by the --authorization-webhook-config-file=SOME_FILENAME flag. The configuration file uses the kubeconfig file format.