The EndpointSlice API is the mechanism that Kubernetes uses to let your Service scale to handle large numbers of backends, and allows the cluster to update its list of healthy backends efficiently.

FEATURE STATE: Kubernetes v1.28 [alpha] (enabled by default: false) Kubernetes 1.31 includes an alpha feature that lets an API Server proxy a resource requests to other peer API servers. This is useful when there are multiple API servers running different versions of Kubernetes in one cluster (for example, during a long-lived rollout to a new release of Kubernetes). This enables cluster administrators to configure highly available clusters that can be upgraded more safely, by directing resource requests (made during the upgrade) to the correct kube-apiserver.

An overview of the key components that make up a Kubernetes cluster.

You can constrain a Pod so that it is restricted to run on particular node(s), or to prefer to run on particular nodes. There are several ways to do this and the recommended approaches all use label selectors to facilitate the selection. Often, you do not need to set any such constraints; the scheduler will automatically do a reasonable placement (for example, spreading your Pods across nodes so as not place Pods on a node with insufficient free resources).

Note: This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information. Add-ons extend the functionality of Kubernetes. This page lists some of the available add-ons and links to their respective installation instructions. The list does not try to be exhaustive.

Networking is a central part of Kubernetes, but it can be challenging to understand exactly how it is expected to work. There are 4 distinct networking problems to address: Highly-coupled container-to-container communications: this is solved by Pods and localhost communications. Pod-to-Pod communications: this is the primary focus of this document. Pod-to-Service communications: this is covered by Services. External-to-Service communications: this is also covered by Services. Kubernetes is all about sharing machines among applications.

This page covers how to customize the components that kubeadm deploys. For control plane components you can use flags in the ClusterConfiguration structure or patches per-node. For the kubelet and kube-proxy you can use KubeletConfiguration and KubeProxyConfiguration, accordingly. All of these options are possible via the kubeadm configuration API. For more details on each field in the configuration you can navigate to our API reference pages. Note:Customizing the CoreDNS deployment of kubeadm is currently not supported.

A security context defines privilege and access control settings for a Pod or Container. Security context settings include, but are not limited to: Discretionary Access Control: Permission to access an object, like a file, is based on user ID (UID) and group ID (GID). Security Enhanced Linux (SELinux): Objects are assigned security labels. Running as privileged or unprivileged. Linux Capabilities: Give a process some privileges, but not all the privileges of the root user.

This page explains two different approaches to setting up a highly available Kubernetes cluster using kubeadm: With stacked control plane nodes. This approach requires less infrastructure. The etcd members and control plane nodes are co-located. With an external etcd cluster. This approach requires more infrastructure. The control plane nodes and etcd members are separated. Before proceeding, you should carefully consider which approach best meets the needs of your applications and environment.

There are many methods and tools for setting up your own production Kubernetes cluster. For example: kubeadm Cluster API: A Kubernetes sub-project focused on providing declarative APIs and tooling to simplify provisioning, upgrading, and operating multiple Kubernetes clusters. kops: An automated cluster provisioning tool. For tutorials, best practices, configuration options and information on reaching out to the community, please check the kOps website for details. kubespray: A composition of Ansible playbooks, inventory, provisioning tools, and domain knowledge for generic OS/Kubernetes clusters configuration management tasks.