When several users or teams share a cluster with a fixed number of nodes, there is a concern that one team could use more than its fair share of resources. Resource quotas are a tool for administrators to address this concern. A resource quota, defined by a ResourceQuota object, provides constraints that limit aggregate resource consumption per namespace. A ResourceQuota can also limit the quantity of objects that can be created in a namespace by API kind, as well as the total amount of infra...| Kubernetes
Kubernetes volumes provide a way for containers in a pod to access and share data via the filesystem. There are different kinds of volume that you can use for different purposes, such as: populating a configuration file based on a ConfigMap or a Secret providing some temporary scratch space for a pod sharing a filesystem between two different containers in the same pod sharing a filesystem between two different pods (even if those Pods run on different nodes) durably storing data so that it s...| Kubernetes
In addition to compiled-in admission plugins, admission plugins can be developed as extensions and run as webhooks configured at runtime. This page describes how to build, configure, use, and monitor admission webhooks. What are admission webhooks? Admission webhooks are HTTP callbacks that receive admission requests and do something with them. You can define two types of admission webhooks, validating admission webhook and mutating admission webhook. Mutating admission webhooks are invoked f...| Kubernetes
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 v...| Kubernetes
Garbage collection is a collective term for the various mechanisms Kubernetes uses to clean up cluster resources. This allows the clean up of resources like the following: Terminated pods Completed Jobs Objects without owner references Unused containers and container images Dynamically provisioned PersistentVolumes with a StorageClass reclaim policy of Delete Stale or expired CertificateSigningRequests (CSRs) Nodes deleted in the following scenarios: On a cloud when the cluster uses a cloud c...| Kubernetes
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 ...| Kubernetes
This document describes persistent volumes in Kubernetes. Familiarity with volumes, StorageClasses and VolumeAttributesClasses is suggested. Introduction Managing storage is a distinct problem from managing compute instances. The PersistentVolume subsystem provides an API for users and administrators that abstracts details of how storage is provided from how it is consumed. To do this, we introduce two new API resources: PersistentVolume and PersistentVolumeClaim. A PersistentVolume (PV) is a...| Kubernetes