Kubernetes Glossary

Annotation

A key-value pair that is used to attach arbitrary non-identifying metadata to objects

Cluster

A set of machines, called nodes, that run containerized applications managed by Kubernetes

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

Controller

A control loop that watches the shared state of the cluster through the apiserver and makes changes attempting to move the current state towards 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

Deployment

An API object that manages a replicated application

Extensions

Extensions are software components that extend and deeply integrate with Kubernetes to support new types of hardware

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

Kubectl

A command line tool for communicating with a Kubernetes API server

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

Minikube

A tool for running Kubernetes locally

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 multiple virtual clusters on the same physical cluster

Node

A node is a worker machine in Kubernetes

Pod

The smallest and simplest Kubernetes object. A Pod represents a set of running containers on your cluster

Pod Security Policy

Enables fine-grained authorization of Pod Priority creation and updates

RBAC (Role-Based Access Control)

Manages authorization decisions, allowing admins to dynamically configure access policies through the Kubernetes API

ReplicaSet

ReplicaSet is the next-generation Replication Controller

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 API object that describes how to access applications, such as a set of Pods , and can describe ports and load-balancers

Service Account

Provides an identity for processes that run in a Pod

StatefulSet

Manages the deployment and scaling of a set of Pods , and provides guarantees about the ordering and uniqueness of these Pods

Taint

A key-value pair and an effect to prevent the scheduling of pods on nodes or node groups

Toleration

A key-value pair and an effect to enable the scheduling of pods on nodes or node groups that have a matching taints

UID

A Kubernetes systems-generated string to uniquely identify objects

Volume

A directory containing data, accessible to the containers in a pod

docker

Docker is a software technology providing operating-system-level virtualization also known as containers

kube-apiserver

Component on the master that exposes the Kubernetes API. It is the front-end for the Kubernetes control plane

kube-controller-manager

Component on the master that runs controllers

kube-proxy

kube-proxy is a network proxy that runs on each node in the cluster

References