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.

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.

A detailed look at the different policy levels defined in the Pod Security Standards.

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.

Finalizers are namespaced keys that tell Kubernetes to wait until specific conditions are met before it fully deletes resources marked for deletion. Finalizers alert controllers to clean up resources the deleted object owned. When you tell Kubernetes to delete an object that has finalizers specified for it, the Kubernetes API marks the object for deletion by populating .metadata.deletionTimestamp, and returns a 202 status code (HTTP "Accepted"). The target object remains in a terminating state while the control plane, or other components, take the actions defined by the finalizers.

Note: While kubeadm is being used as the management tool for external etcd nodes in this guide, please note that kubeadm does not plan to support certificate rotation or upgrades for such nodes. The long-term plan is to empower the tool etcdadm to manage these aspects. 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.

Node Conformance Test Node conformance test is a containerized test framework that provides a system verification and functionality test for a node. The test validates whether the node meets the minimum requirements for Kubernetes; a node that passes the test is qualified to join a Kubernetes cluster. Node Prerequisite To run node conformance test, a node must satisfy the same prerequisites as a standard Kubernetes node. At a minimum, the node should have the following daemons installed:

This page describes the resources available to Containers in the Container environment. Container environment The Kubernetes Container environment provides several important resources to Containers: A filesystem, which is a combination of an image and one or more volumes. Information about the Container itself. Information about other objects in the cluster. Container information The hostname of a Container is the name of the Pod in which the Container is running. It is available through the hostname command or the gethostname function call in libc.

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.

You can use Kubernetes annotations to attach arbitrary non-identifying metadata to objects. Clients such as tools and libraries can retrieve this metadata. Attaching metadata to objects You can use either labels or annotations to attach metadata to Kubernetes objects. Labels can be used to select objects and to find collections of objects that satisfy certain conditions. In contrast, annotations are not used to identify and select objects. The metadata in an annotation can be small or large, structured or unstructured, and can include characters not permitted by labels.