Black lives matter.
We stand in solidarity with the Black community.
Racism is unacceptable.
It conflicts with the core values of the Kubernetes project and our community does not tolerate it.
Глосарій
Даний словник створений як повний стандартизований список термінології Kubernetes. Він включає в себе технічні терміни, специфічні для Kubernetes, а також більш загальні терміни, необхідні для кращого розуміння контексту.
Відфільтрувати терміни за тегами
.
Architecture
Community
Core Object
Extension
Fundamental
Networking
Operation
Security
Storage
Tool
User Type
Workload
Вибрати все
Очистити вибір
Натисність на [+] для отримання розширеного пояснення конкретного терміна.
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Annotation
A key-value pair that is used to attach arbitrary non-identifying metadata to objects.
[+]The metadata in an annotation can be small or large, structured or unstructured, and can include characters not permitted by labelsTags objects with identifying attributes that are meaningful and relevant to users. . Clients such as tools and libraries can retrieve this metadata.
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API Group
A set of related paths in Kubernetes API.
[+]You can enable or disable each API group by changing the configuration of your API server. You can also disable or enable paths to specific resources. API group makes it easier to extend the Kubernetes API. The API group is specified in a REST path and in the
apiVersionfield of a serialized object.- Read API Group for more information.
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API-серверТакож відомий як:kube-apiserver
API-сервер є компонентом площини управлінняШар оркестрації контейнерів, який надає API та інтерфейси для визначення, розгортання і управління життєвим циклом контейнерів. Kubernetes, через який можна отримати доступ до API Kubernetes. API-сервер є фронтендом площини управління Kubernetes.
[+]Основною реалізацією Kubernetes API-сервера є kube-apiserver. kube-apiserver підтримує горизонтальне масштабування, тобто масштабується за рахунок збільшення кількості інстансів. kube-apiserver можна запустити на декількох інстансах, збалансувавши між ними трафік.
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cgroup (control group)
A group of Linux processes with optional resource isolation, accounting and limits.
[+]cgroup is a Linux kernel feature that limits, accounts for, and isolates the resource usage (CPU, memory, disk I/O, network) for a collection of processes.
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Container
A lightweight and portable executable image that contains software and all of its dependencies.
[+]Containers decouple applications from underlying host infrastructure to make deployment easier in different cloud or OS environments, and for easier scaling.
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Container Environment Variables
Container environment variables are name=value pairs that provide useful information into containers running in a podA Pod represents a set of running containers in your cluster.
[+]Container environment variables provide information that is required by the running containerized applications along with information about important resources to the containersA lightweight and portable executable image that contains software and all of its dependencies. . For example, file system details, information about the container itself, and other cluster resources such as service endpoints.
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Container Runtime
The container runtime is the software that is responsible for running containers.
[+]Kubernetes supports several container runtimes: DockerDocker is a software technology providing operating-system-level virtualization also known as containers. , containerdA container runtime with an emphasis on simplicity, robustness and portability , CRI-OA lightweight container runtime specifically for Kubernetes , and any implementation of the Kubernetes CRI (Container Runtime Interface).
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Controller
In Kubernetes, controllers are control loops that watch the state of your clusterA set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node. , then make or request changes where needed. Each controller tries to move the current cluster state closer to the desired state.
[+]Controllers watch the shared state of your cluster through the apiserverControl plane component that serves the Kubernetes API. (part of the Control PlaneThe container orchestration layer that exposes the API and interfaces to define, deploy, and manage the lifecycle of containers. ).
Some controllers also run inside the control plane, providing control loops that are core to Kubernetes' operations. For example: the deployment controller, the daemonset controller, the namespace controller, and the persistent volume controller (and others) all run within the kube-controller-managerControl Plane component that runs controller processes. .
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CustomResourceDefinition
Custom code that defines a resource to add to your Kubernetes API server without building a complete custom server.
[+]Custom Resource Definitions let you extend the Kubernetes API for your environment if the publicly supported API resources can't meet your needs.
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DaemonSet
Ensures a copy of a PodA Pod represents a set of running containers in your cluster. is running across a set of nodes in a clusterA set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node. .
[+]Used to deploy system daemons such as log collectors and monitoring agents that typically must run on every NodeA node is a worker machine in Kubernetes. .
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Deployment
Об'єкт API, що керує реплікованим застосунком.
[+]Кожна репліка являє собою PodНайменший і найпростіший об'єкт Kubernetes. Pod являє собою групу контейнерів, що запущені у вашому кластері. ; Pod'и розподіляються між вузлами кластера.
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Device Plugin
Device plugins run on worker NodesA node is a worker machine in Kubernetes. and provide Pods A Pod represents a set of running containers in your cluster. with access to resources, such as local hardware, that require vendor-specific initialization or setup steps.
[+]Device plugins advertise resources to the kubeletAn agent that runs on each node in the cluster. It makes sure that containers are running in a pod. , so that workload Pods can access hardware features that relate to the Node where that Pod is running. You can deploy a device plugin as a DaemonSetEnsures a copy of a Pod is running across a set of nodes in a cluster. , or install the device plugin software directly on each target Node.
See Device Plugins for more information.
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Disruption
Disruptions are events that lead to one or more PodsA Pod represents a set of running containers in your cluster. going out of service. A disruption has consequences for workload resources, such as DeploymentManages a replicated application on your cluster. , that rely on the affected Pods.
[+]If you, as cluster operator, destroy a Pod that belongs to an application, Kubernetes terms that a voluntary disruption. If a Pod goes offline because of a Node failure, or an outage affecting a wider failure zone, Kubernetes terms that an involuntary disruption.
See Disruptions for more information.
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Docker
Docker (specifically, Docker Engine) is a software technology providing operating-system-level virtualization also known as containersA lightweight and portable executable image that contains software and all of its dependencies. .
[+]Docker uses the resource isolation features of the Linux kernel such as cgroups and kernel namespaces, and a union-capable file system such as OverlayFS and others to allow independent containers to run within a single Linux instance, avoiding the overhead of starting and maintaining virtual machines (VMs).
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Ephemeral Container
A ContainerA lightweight and portable executable image that contains software and all of its dependencies. type that you can temporarily run inside a PodA Pod represents a set of running containers in your cluster. .
[+]If you want to investigate a Pod that's running with problems, you can add an ephemeral container to that Pod and carry out diagnostics. Ephemeral containers have no resource or scheduling guarantees, and you should not use them to run any part of the workload itself.
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Extensions
Extensions are software components that extend and deeply integrate with Kubernetes to support new types of hardware.
[+]Most cluster administrators will use a hosted or distribution instance of Kubernetes. As a result, most Kubernetes users will need to install extensions and fewer will need to author new ones.
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Image
Stored instance of a ContainerA lightweight and portable executable image that contains software and all of its dependencies. that holds a set of software needed to run an application.
[+]A way of packaging software that allows it to be stored in a container registry, pulled to a local system, and run as an application. Meta data is included in the image that can indicate what executable to run, who built it, and other information.
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Init Container
One or more initialization containersA lightweight and portable executable image that contains software and all of its dependencies. that must run to completion before any app containers run.
[+]Initialization (init) containers are like regular app containers, with one difference: init containers must run to completion before any app containers can start. Init containers run in series: each init container must run to completion before the next init container begins.
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Job
A finite or batch task that runs to completion.
[+]Creates one or more PodA Pod represents a set of running containers in your cluster. objects and ensures that a specified number of them successfully terminate. As Pods successfully complete, the Job tracks the successful completions.
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kube-controller-manager
Компонент площини управління, який запускає процеси контролераA 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. .
[+]За логікою, кожен контролерA 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. є окремим процесом. Однак для спрощення їх збирають в один бінарний файл і запускають як єдиний процес.
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kube-proxy
kube-proxy є мережевим проксі, що запущене на кожному вузлі кластера і реалізує частину концепції Kubernetes ServiceСпосіб відкрити доступ до застосунку, що запущений на декількох Pod'ах у вигляді мережевої служби. .
[+]kube-proxy відповідає за мережеві правила на вузлах. Ці правила обумовлюють підключення по мережі до ваших Pod'ів всередині чи поза межами кластера.
kube-proxy використовує шар фільтрації пакетів операційної системи, за наявності такого. В іншому випадку kube-proxy скеровує трафік самостійно.
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Kubectl
A command line tool for communicating with a Kubernetes APIThe application that serves Kubernetes functionality through a RESTful interface and stores the state of the cluster. server.
[+]You can use kubectl to create, inspect, update, and delete Kubernetes objects.
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Kubelet
Агент, що запущений на кожному вузлі кластера. Забезпечує запуск і роботу контейнерів у Pod'ах.
[+]kubelet використовує специфікації PodSpecs, які надаються за допомогою різних механізмів, і забезпечує працездатність і справність усіх контейнерів, що описані у PodSpecs. kubelet керує лише тими контейнерами, що були створені Kubernetes.
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Kubernetes API
The application that serves Kubernetes functionality through a RESTful interface and stores the state of the cluster.
[+]Kubernetes resources and "records of intent" are all stored as API objects, and modified via RESTful calls to the API. The API allows configuration to be managed in a declarative way. Users can interact with the Kubernetes API directly, or via tools like
kubectl. The core Kubernetes API is flexible and can also be extended to support custom resources. -
Label
Tags objects with identifying attributes that are meaningful and relevant to users.
[+]Labels are key/value pairs that are attached to objects such as PodsA Pod represents a set of running containers in your cluster. . They are used to organize and to select subsets of objects.
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LimitRange
Provides constraints to limit resource consumption per ContainersA lightweight and portable executable image that contains software and all of its dependencies. or PodsA Pod represents a set of running containers in your cluster. in a namespace.
[+]LimitRange limits the quantity of objects that can be created by type, as well as the amount of compute resources that may be requested/consumed by individual ContainersA lightweight and portable executable image that contains software and all of its dependencies. or PodsA Pod represents a set of running containers in your cluster. in a namespace.
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Logging
Logs are the list of events that are logged by clusterA set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node. or application.
[+]Application and systems logs can help you understand what is happening inside your cluster. The logs are particularly useful for debugging problems and monitoring cluster activity.
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Manifest
Specification of a Kubernetes API object in JSON or YAML format.
[+]A manifest specifies the desired state of an object that Kubernetes will maintain when you apply the manifest. Each configuration file can contain multiple manifests.
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Master
Legacy term, used as synonym for nodesA node is a worker machine in Kubernetes. hosting the control planeThe container orchestration layer that exposes the API and interfaces to define, deploy, and manage the lifecycle of containers. .
[+]The term is still being used by some provisioning tools, such as kubeadmA tool for quickly installing Kubernetes and setting up a secure cluster. , and managed services, to labelTags objects with identifying attributes that are meaningful and relevant to users. nodesA node is a worker machine in Kubernetes. with
kubernetes.io/roleand control placement of control planeThe container orchestration layer that exposes the API and interfaces to define, deploy, and manage the lifecycle of containers. podsA Pod represents a set of running containers in your cluster. . -
Minikube
A tool for running Kubernetes locally.
[+]Minikube runs a single-node cluster inside a VM on your computer. You can use Minikube to try Kubernetes in a learning environment.
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Mirror Pod
A podA Pod represents a set of running containers in your cluster. object that a kubelet uses to represent a static podA pod managed directly by the kubelet daemon on a specific node.
[+]When the kubelet finds a static pod in its configuration, it automatically tries to create a Pod object on the Kubernetes API server for it. This means that the pod will be visible on the API server, but cannot be controlled from there.
(For example, removing a mirror pod will not stop the kubelet daemon from running it).
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Name
A client-provided string that refers to an object in a resource URL, such as
[+]/api/v1/pods/some-name.Only one object of a given kind can have a given name at a time. However, if you delete the object, you can make a new object with the same name.
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Namespace
An abstraction used by Kubernetes to support multiple virtual clusters on the same physical clusterA set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node. .
[+]Namespaces are used to organize objects in a cluster and provide a way to divide cluster resources. Names of resources need to be unique within a namespace, but not across namespaces.
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Node
A node is a worker machine in Kubernetes.
[+]A worker node may be a VM or physical machine, depending on the cluster. It has local daemons or services necessary to run PodsA Pod represents a set of running containers in your cluster. and is managed by the control plane. The daemons on a node include kubeletAn agent that runs on each node in the cluster. It makes sure that containers are running in a pod. , kube-proxykube-proxy is a network proxy that runs on each node in the cluster. , and a container runtime implementing the CRIAn API for container runtimes to integrate with kubelet such as DockerDocker is a software technology providing operating-system-level virtualization also known as containers. .
In early Kubernetes versions, Nodes were called “Minions”.
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Pod
Найменший і найпростіший об'єкт Kubernetes. Pod являє собою групу контейнерівA lightweight and portable executable image that contains software and all of its dependencies. , що запущені у вашому кластері.
[+]Як правило, в одному Pod'і запускається один контейнер. У Pod'і також можуть бути запущені допоміжні контейнери, що забезпечують додаткову функціональність, наприклад, логування. Управління Pod'ами зазвичай здійснює DeploymentОб'єкт API, що керує реплікованим застосунком. .
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Pod Lifecycle
The sequence of states through which a Pod passes during its lifetime.
[+]The Pod Lifecycle is defined by the states or phases of a Pod. There are five possible Pod phases: Pending, Running, Succeeded, Failed, and Unknown. A high-level description of the Pod state is summarized in the PodStatus
phasefield. -
Pod Security Policy
Enables fine-grained authorization of PodA Pod represents a set of running containers in your cluster. creation and updates.
[+]A cluster-level resource that controls security sensitive aspects of the Pod specification. The
PodSecurityPolicyobjects define a set of conditions that a Pod must run with in order to be accepted into the system, as well as defaults for the related fields. Pod Security Policy control is implemented as an optional admission controller. -
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.
[+]QoS Class of a Pod is set at creation time based on its compute resources requests and limits settings. QoS classes are used to make decisions about Pods scheduling and eviction. Kubernetes can assign one of the following QoS classes to a Pod:
Guaranteed,BurstableorBestEffort. -
RBAC (Role-Based Access Control)
Manages authorization decisions, allowing admins to dynamically configure access policies through the Kubernetes APIThe application that serves Kubernetes functionality through a RESTful interface and stores the state of the cluster. .
[+]RBAC utilizes roles, which contain permission rules, and role bindings, which grant the permissions defined in a role to a set of users.
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ReplicaSet
A ReplicaSet (aims to) maintain a set of replica Pods running at any given time.
[+]Workload objects such as DeploymentManages a replicated application on your cluster. make use of ReplicaSets to ensure that the configured number of PodsA Pod represents a set of running containers in your cluster. are running in your cluster, based on the spec of that ReplicaSet.
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Resource Quotas
Provides constraints that limit aggregate resource consumption per NamespaceAn abstraction used by Kubernetes to support multiple virtual clusters on the same physical cluster. .
[+]Limits the quantity of objects that can be created in a namespace by type, as well as the total amount of compute resources that may be consumed by resources in that project.
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Service
Це абстрактний спосіб відкрити доступ до застосунку, що працює як один (або декілька) Pod'івНайменший і найпростіший об'єкт Kubernetes. Pod являє собою групу контейнерів, що запущені у вашому кластері. у вигляді мережевої служби.
[+]Переважно група Pod'ів визначається як Service за допомогою селектораДозволяє користувачам фільтрувати ресурси за мітками. . Додання або вилучення Pod'ів змінить групу Pod'ів, визначених селектором. Service забезпечує надходження мережевого трафіка до актуальної групи Pod'ів для підтримки робочого навантаження.
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ServiceAccount
Provides an identity for processes that run in a PodA Pod represents a set of running containers in your cluster. .
[+]When processes inside Pods access the cluster, they are authenticated by the API server as a particular service account, for example,
default. When you create a Pod, if you do not specify a service account, it is automatically assigned the default service account in the same NamespaceAn abstraction used by Kubernetes to support multiple virtual clusters on the same physical cluster. . -
shuffle sharding
A technique for assigning requests to queues that provides better isolation than hashing modulo the number of queues.
[+]We are often concerned with insulating different flows of requests from each other, so that a high-intensity flow does not crowd out low-intensity flows. A simple way to put requests into queues is to hash some characteristics of the request, modulo the number of queues, to get the index of the queue to use. The hash function uses as input characteristics of the request that align with flows. For example, in the Internet this is often the 5-tuple of source and destination address, protocol, and source and destination port.
That simple hash-based scheme has the property that any high-intensity flow will crowd out all the low-intensity flows that hash to the same queue. Providing good insulation for a large number of flows requires a large number of queues, which is problematic. Shuffle sharding is a more nimble technique that can do a better job of insulating the low-intensity flows from the high-intensity flows. The terminology of shuffle sharding uses the metaphor of dealing a hand from a deck of cards; each queue is a metaphorical card. The shuffle sharding technique starts with hashing the flow-identifying characteristics of the request, to produce a hash value with dozens or more of bits. Then the hash value is used as a source of entropy to shuffle the deck and deal a hand of cards (queues). All the dealt queues are examined, and the request is put into one of the examined queues with the shortest length. With a modest hand size, it does not cost much to examine all the dealt cards and a given low-intensity flow has a good chance to dodge the effects of a given high-intensity flow. With a large hand size it is expensive to examine the dealt queues and more difficult for the low-intensity flows to dodge the collective effects of a set of high-intensity flows. Thus, the hand size should be chosen judiciously.
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StatefulSet
Manages the deployment and scaling of a set of PodsA Pod represents a set of running containers in your cluster. , and provides guarantees about the ordering and uniqueness of these Pods.
[+]Like a DeploymentManages a replicated application on your cluster. , a StatefulSet manages Pods that are based on an identical container spec. Unlike a Deployment, a StatefulSet maintains a sticky identity for each of their Pods. These pods are created from the same spec, but are not interchangeable: each has a persistent identifier that it maintains across any rescheduling.
If you want to use storage volumes to provide persistence for your workload, you can use a StatefulSet as part of the solution. Although individual Pods in a StatefulSet are susceptible to failure, the persistent Pod identifiers make it easier to match existing volumes to the new Pods that replace any that have failed.
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Static Pod
A podA Pod represents a set of running containers in your cluster. managed directly by the kubelet daemon on a specific node,
[+]without the API server observing it.
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Taint
A core object consisting of three required properties: key, value, and effect. Taints prevent the scheduling of PodsA Pod represents a set of running containers in your cluster. on nodesA node is a worker machine in Kubernetes. or node groups.
[+]Taints and tolerationsA core object consisting of three required properties: key, value, and effect. Tolerations enable the scheduling of pods on nodes or node groups that have a matching taint. work together to ensure that pods are not scheduled onto inappropriate nodes. One or more taints are applied to a node. A node should only schedule a Pod with the matching tolerations for the configured taints.
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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 taintsA core object consisting of three required properties: key, value, and effect. Taints prevent the scheduling of pods on nodes or node groups. .
[+]Tolerations and taintsA core object consisting of three required properties: key, value, and effect. Taints prevent the scheduling of pods on nodes or node groups. work together to ensure that pods are not scheduled onto inappropriate nodes. One or more tolerations are applied to a podA Pod represents a set of running containers in your cluster. . A toleration indicates that the podA Pod represents a set of running containers in your cluster. is allowed (but not required) to be scheduled on nodes or node groups with matching taintsA core object consisting of three required properties: key, value, and effect. Taints prevent the scheduling of pods on nodes or node groups. .
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UID
A Kubernetes systems-generated string to uniquely identify objects.
[+]Every object created over the whole lifetime of a Kubernetes cluster has a distinct UID. It is intended to distinguish between historical occurrences of similar entities.
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Volume
A directory containing data, accessible to the containersA lightweight and portable executable image that contains software and all of its dependencies. in a PodA Pod represents a set of running containers in your cluster. .
[+]A Kubernetes volume lives as long as the Pod that encloses it. Consequently, a volume outlives any containers that run within the Pod, and data in the volume is preserved across container restarts.
See storage for more information.
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Workload
A workload is an application running on Kubernetes.
[+]Various core objects that represent different types or parts of a workload include the DaemonSet, Deployment, Job, ReplicaSet, and StatefulSet objects.
For example, a workload that has a web server and a database might run the database in one StatefulSetManages deployment and scaling of a set of Pods, with durable storage and persistent identifiers for each Pod. and the web server in a DeploymentManages a replicated application on your cluster. .
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ЗастосункиШар, в якому запущено контейнерізовані застосунки. [+]
Шар, в якому запущено контейнерізовані застосунки.
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Кластер
Група робочих машин (їх називають вузлами), на яких запущені контейнерізовані застосунки. Кожен кластер має щонайменше один вузол.
[+]На робочих вузлах розміщуються Pod'и, які є складовими застосунку. Площина управління керує робочими вузлами і Pod'ами кластера. У прод оточеннях площина управління зазвичай розповсюджується на багато комп'ютерів, а кластер складається з багатьох вузлів для забезпечення відмовостійкості і високої доступності.
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Площина данихШар, який надає контейнерам ресурси, такі як ЦПУ, пам'ять, мережа і сховище даних для того, щоб контейнери могли працювати і підключатися до мережі. [+]
Шар, який надає контейнерам ресурси, такі як ЦПУ, пам'ять, мережа і сховище даних для того, щоб контейнери могли працювати і підключатися до мережі.
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Площина управлінняШар оркестрації контейнерів, який надає API та інтерфейси для визначення, розгортання і управління життєвим циклом контейнерів. [+]
Шар оркестрації контейнерів, який надає API та інтерфейси для визначення, розгортання і управління життєвим циклом контейнерів.
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Селектор
Дозволяє користувачам фільтрувати ресурси за мітками.
[+]Селектори застосовуються при створенні запитів для фільтрації ресурсів за міткамиTags objects with identifying attributes that are meaningful and relevant to users. .