Note: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details. FEATURE STATE: Kubernetes v1.11 [stable] The lifecycle of the kubeadm CLI tool is decoupled from the kubelet, which is a daemon that runs on each node within the Kubernetes cluster. The kubeadm CLI tool is executed by the user when Kubernetes is initialized or upgraded, whereas the kubelet is always running in the background.

By default, kubeadm runs a local etcd instance on each control plane node. It is also possible to treat the etcd cluster as external and provision etcd instances on separate hosts. The differences between the two approaches are covered in the Options for Highly Available topology page. This task walks through the process of creating a high availability external etcd cluster of three members that can be used by kubeadm during cluster creation.

Kubernetes supports running nodes on either Linux or Windows. You can mix both kinds of node within a single cluster. This page provides an overview to networking specific to the Windows operating system. Container networking on Windows Networking for Windows containers is exposed through CNI plugins. Windows containers function similarly to virtual machines in regards to networking. Each container has a virtual network adapter (vNIC) which is connected to a Hyper-V virtual switch (vSwitch).

Legacy API for managing workloads that can scale horizontally. Superseded by the Deployment and ReplicaSet APIs.

In Kubernetes, a VolumeSnapshot represents a snapshot of a volume on a storage system. This document assumes that you are already familiar with Kubernetes persistent volumes. Introduction Similar to how API resources PersistentVolume and PersistentVolumeClaim are used to provision volumes for users and administrators, VolumeSnapshotContent and VolumeSnapshot API resources are provided to create volume snapshots for users and administrators. A VolumeSnapshotContent is a snapshot taken from a volume in the cluster that has been provisioned by an administrator.

On Linux, control groups constrain resources that are allocated to processes. The kubelet and the underlying container runtime need to interface with cgroups to enforce resource management for pods and containers which includes cpu/memory requests and limits for containerized workloads. There are two versions of cgroups in Linux: cgroup v1 and cgroup v2. cgroup v2 is the new generation of the cgroup API. What is cgroup v2? FEATURE STATE: Kubernetes v1.

This document highlights and consolidates configuration best practices that are introduced throughout the user guide, Getting Started documentation, and examples. This is a living document. If you think of something that is not on this list but might be useful to others, please don't hesitate to file an issue or submit a PR. General Configuration Tips When defining configurations, specify the latest stable API version. Configuration files should be stored in version control before being pushed to the cluster.

When you specify a Pod, you can optionally specify how much of each resource a container needs. The most common resources to specify are CPU and memory (RAM); there are others. When you specify the resource request for containers in a Pod, the kube-scheduler uses this information to decide which node to place the Pod on. When you specify a resource limit for a container, the kubelet enforces those limits so that the running container is not allowed to use more of that resource than the limit you set.

FEATURE STATE: Kubernetes v1.15 [stable] Client certificates generated by kubeadm expire after 1 year. This page explains how to manage certificate renewals with kubeadm. It also covers other tasks related to kubeadm certificate management. The Kubernetes project recommends upgrading to the latest patch releases promptly, and to ensure that you are running a supported minor release of Kubernetes. Following this recommendation helps you to stay secure. Before you begin You should be familiar with PKI certificates and requirements in Kubernetes.

This page explains how to upgrade a Kubernetes cluster created with kubeadm from version 1.33.x to version 1.34.x, and from version 1.34.x to 1.34.y (where y > x). Skipping MINOR versions when upgrading is unsupported. For more details, please visit Version Skew Policy. To see information about upgrading clusters created using older versions of kubeadm, please refer to following pages instead: Upgrading a kubeadm cluster from 1.32 to 1.33 Upgrading a kubeadm cluster from 1.