Affinity
In Kubernetes, affinity is a set of rules that give hints to the scheduler about where to place pods.
Annotation
A key-value pair that is used to attach arbitrary non-identifying metadata to objects.
API Group
A set of related paths in Kubernetes API.
API server
Also known as:kube-apiserver
The API server is a component of the Kubernetes control plane that exposes the Kubernetes API. The API server is the front end for the Kubernetes control plane. Applications The layer where various containerized applications run.
cgroup (control group)
A group of Linux processes with optional resource isolation, accounting and limits.
Cluster
A set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node.
Container
A lightweight and portable executable image that contains software and all of its dependencies. Container Environment Variables
Container environment variables are name=value pairs that provide useful information into containers running in a pod
Container Runtime
The container runtime is the software that is responsible for running containers.
Container runtime interface (CRI)
The container runtime interface (CRI) is an API for container runtimes to integrate with kubelet on a node.
Control Plane
The container orchestration layer that exposes the API and interfaces to define, deploy, and manage the lifecycle of containers.
Controller
In Kubernetes, controllers are control loops that watch the state of your cluster, then make or request changes where needed. Each controller tries to move the current cluster state closer to the desired state.
CustomResourceDefinition
Custom code that defines a resource to add to your Kubernetes API server without building a complete custom server.
DaemonSet
Ensures a copy of a Pod is running across a set of nodes in a cluster. Data Plane The layer that provides capacity such as CPU, memory, network, and storage so that the containers can run and connect to a network.
Deployment
An API object that manages a replicated application, typically by running Pods with no local state. Device Plugin
Device plugins run on worker Nodes and provide Pods with access to resources, such as local hardware, that require vendor-specific initialization or setup steps.
Disruption
Disruptions are events that lead to one or more Pods going out of service. A disruption has consequences for workload resources, such as Deployment, that rely on the affected Pods.
Docker
Docker (specifically, Docker Engine) is a software technology providing operating-system-level virtualization also known as containers.
Dockershim
The dockershim is a component of Kubernetes version 1.23 and earlier. It allows the kubelet to communicate with Docker Engine.
Ephemeral Container
A Container type that you can temporarily run inside a Pod.
Event
Each Event is a report of an event somewhere in the cluster. It generally denotes some state change in the system.[+] Extensions
Extensions are software components that extend and deeply integrate with Kubernetes to support new types of hardware.
Feature gate
Feature gates are a set of keys (opaque string values) that you can use to control which Kubernetes features are enabled in your cluster.
Finalizer
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.
Garbage Collection
Garbage collection is a collective term for the various mechanisms Kubernetes uses to clean up cluster resources. Image
Stored instance of a Container that holds a set of software needed to run an application.
Init Container
One or more initialization containers that must run to completion before any app containers run.
Job
A finite or batch task that runs to completion.
kube-controller-manager
Control plane component that runs controller processes.
kube-proxy
kube-proxy is a network proxy that runs on each node in your cluster, implementing part of the Kubernetes Service concept.
Kubectl Also known as:kubectl
Command line tool for communicating with a Kubernetes cluster's control plane, using the Kubernetes API. Kubelet
An agent that runs on each node in the cluster. It makes sure that containers are running in a Pod. Kubernetes API
The application that serves Kubernetes functionality through a RESTful interface and stores the state of the cluster.
Label
Tags objects with identifying attributes that are meaningful and relevant to users.
LimitRange
Provides constraints to limit resource consumption per Containers or Pods in a namespace.
Logging
Logs are the list of events that are logged by cluster or application.
Manifest
Specification of a Kubernetes API object in JSON or YAML format.
Master
Legacy term, used as synonym for nodes hosting the control plane.
Minikube
A tool for running Kubernetes locally.
Mirror Pod
A pod object that a kubelet uses to represent a static pod
Name
A client-provided string that refers to an object in a resource URL, such as /api/v1/pods/some-name.
Namespace
An abstraction used by Kubernetes to support isolation of groups of resources within a single cluster.
Node
A node is a worker machine in Kubernetes. Object
An entity in the Kubernetes system. The Kubernetes API uses these entities to represent the state of your cluster.
Pod
The smallest and simplest Kubernetes object. A Pod represents a set of running containers on your cluster.
Pod Lifecycle
The sequence of states through which a Pod passes during its lifetime.
Pod Security Policy
Enables fine-grained authorization of Pod creation and updates.
QoS Class
QoS Class (Quality of Service Class) provides a way for Kubernetes to classify Pods within the cluster into several classes and make decisions about scheduling and eviction.
RBAC (Role-Based Access Control)
Manages authorization decisions, allowing admins to dynamically configure access policies through the Kubernetes API.
ReplicaSet
A ReplicaSet (aims to) maintain a set of replica Pods running at any given time. Resource Quotas
Provides constraints that limit aggregate resource consumption per Namespace.
Selector
Allows users to filter a list of resources based on labels.
Service
An abstract way to expose an application running on a set of Pods as a network service.
ServiceAccount
Provides an identity for processes that run in a Pod.
Shuffle-sharding
A techni
que for assigning requests to queues that provides better isolation than hashing modulo the number of queues.
StatefulSet
Manages the deployment and scaling of a set of Pods, and provides guarantees about the ordering and uniqueness of these Pods.
Static Pod
A pod managed directly by the kubelet daemon on a specific node,
Taint
A core object consisting of three required properties: key, value, and effect. Taints prevent the scheduling of Pods on nodes or node groups.
Toleration
A core object consisting of three required properties: key, value, and effect. Tolerations enable the scheduling of pods on nodes or node groups that have matching taints.
UID
A Kubernetes systems-generated string to uniquely identify objects.
Volume
A directory containing data, accessible to the containers in a Pod.
Workload
A workload is an application running on Kubernetes.
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