sigs.k8s.io/cluster-api@v1.7.1/docs/book/src/reference/glossary.md (about)

     1  # Table of Contents
     2  
     3  [A](#a) | [B](#b) | [C](#c) | [D](#d) | [E](#e) | [H](#h) | [I](#i) | [K](#k) | [L](#l)| [M](#m) | [N](#n) | [O](#o) | [P](#p) | [R](#r) | [S](#s) | [T](#t) | [W](#w)
     4  
     5  # A
     6  ---
     7  
     8  ### Add-ons
     9  
    10  Services beyond the fundamental components of Kubernetes.
    11  
    12  * __Core Add-ons__: Addons that are required to deploy a Kubernetes-conformant cluster: DNS, kube-proxy, CNI.
    13  * __Additional Add-ons__: Addons that are not required for a Kubernetes-conformant cluster (e.g. metrics/Heapster, Dashboard).
    14  
    15  # B
    16  ---
    17  
    18  ### Bootstrap
    19  
    20  The process of turning a server into a Kubernetes node. This may involve assembling data to provide when creating the server that backs the Machine, as well as runtime configuration of the software running on that server.
    21  
    22  ### Bootstrap cluster
    23  
    24  A temporary cluster that is used to provision a Target Management cluster.
    25  
    26  ### Bootstrap provider
    27  
    28  Refers to a [provider](#provider) that implements a solution for the [bootstrap](#bootstrap) process.
    29  Bootstrap provider's interaction with Cluster API is based on what is defined in the [Cluster API contract](#contract).
    30  
    31  See [CABPK](#cabpk).
    32  
    33  # C
    34  ---
    35  
    36  ### CAEP
    37  Cluster API Enhancement Proposal - patterned after [KEP](https://git.k8s.io/enhancements/keps/README.md). See [template](https://github.com/kubernetes-sigs/cluster-api/blob/main/docs/proposals/YYYYMMDD-template.md)
    38  
    39  ### CAPI
    40  Core Cluster API
    41  
    42  ### CAPA
    43  Cluster API Provider AWS
    44  
    45  ### CABPK
    46  Cluster API Bootstrap Provider Kubeadm
    47  
    48  ### CABPOCNE
    49  Cluster API Bootstrap Provider Oracle Cloud Native Environment (OCNE)
    50  
    51  ### CACPOCNE
    52  Cluster API Control Plane Provider Oracle Cloud Native Environment (OCNE)
    53  
    54  ### CAPC
    55  Cluster API Provider CloudStack
    56  
    57  ### CAPD
    58  Cluster API Provider Docker
    59  
    60  ### CAPDO
    61  Cluster API Provider DigitalOcean
    62  
    63  ### CAPG
    64  Cluster API Google Cloud Provider
    65  
    66  ### CAPH
    67  Cluster API Provider Hetzner
    68  
    69  ### CAPHV
    70  Cluster API Provider Hivelocity
    71  
    72  ### CAPIBM
    73  Cluster API Provider IBM Cloud
    74  
    75  ### CAPIO
    76  Cluster API Operator
    77  
    78  ### CAPM3
    79  Cluster API Provider Metal3
    80  
    81  ### CAPN
    82  Cluster API Provider Nested
    83  
    84  ### CAPX
    85  Cluster API Provider Nutanix
    86  
    87  ### CAPKK
    88  Cluster API Provider KubeKey
    89  
    90  ### CAPK
    91  Cluster API Provider Kubevirt
    92  
    93  ### CAPO
    94  Cluster API Provider OpenStack
    95  
    96  ### CAPOSC
    97  Cluster API Provider Outscale
    98  
    99  ### CAPOCI
   100  Cluster API Provider Oracle Cloud Infrastructure (OCI)
   101  
   102  ### CAPV
   103  Cluster API Provider vSphere
   104  
   105  ### CAPVC
   106  Cluster API Provider vcluster
   107  
   108  ### CAPVCD
   109  Cluster API Provider VMware Cloud Director
   110  
   111  ### CAPZ
   112  Cluster API Provider Azure
   113  
   114  ### CAIPAMIC
   115  Cluster API IPAM Provider In Cluster
   116  
   117  ### Cloud provider
   118  
   119  Or __Cloud service provider__
   120  
   121  Refers to an information technology (IT) company that provides computing resources (e.g. AWS, Azure, Google, etc.).
   122  
   123  ### Cluster
   124  
   125  A full Kubernetes deployment. See Management Cluster and Workload Cluster.
   126  
   127  ### ClusterClass
   128  
   129  A collection of templates that define a topology (control plane and workers) to be used to continuously reconcile one or more Clusters.
   130  See [ClusterClass](../tasks/experimental-features/cluster-class/index.md)
   131  
   132  ### Cluster API
   133  
   134  Or __Cluster API project__
   135  
   136  The Cluster API sub-project of the SIG-cluster-lifecycle. It is also used to refer to the software components, APIs, and community that produce them.
   137  
   138  See [core provider](#core-provider)
   139  
   140  ### Cluster API Runtime
   141  
   142  The Cluster API execution model, a set of controllers cooperating in managing the Kubernetes cluster lifecycle.
   143  
   144  ### Cluster Infrastructure
   145  
   146  or __Kubernetes Cluster Infrastructure__
   147  
   148  Defines the **infrastructure that supports a Kubernetes cluster**, like e.g. VPC, security groups, load balancers, etc. Please note that in the context of managed Kubernetes some of those components are going to be provided by the corresponding abstraction for a specific Cloud provider (EKS, OKE, AKS etc), and thus Cluster API should not take care of managing a subset or all those components.
   149  
   150  ### Contract
   151  
   152  Or __Cluster API contract__
   153  
   154  Defines a set of rules a [provider](#provider) is expected to comply with in order to interact with Cluster API.
   155  Those rules can be in the form of CustomResourceDefinition (CRD) fields and/or expected behaviors to be implemented.
   156  
   157  ### Control plane
   158  
   159  The set of Kubernetes services that form the basis of a cluster. See also [https://kubernetes.io/docs/concepts/#kubernetes-control-plane](https://kubernetes.io/docs/concepts/#kubernetes-control-plane) There are two variants:
   160  
   161  * __Self-provisioned__: A Kubernetes control plane consisting of pods or machines wholly managed by a single Cluster API deployment.
   162  * __External__ or __Managed__: A control plane offered and controlled by some system other than Cluster API (e.g., GKE, AKS, EKS, IKS).
   163  
   164  ### Control plane provider
   165  
   166  Refers to a [provider](#provider) that implements a solution for the management of a Kubernetes [control plane](#control-plane).
   167  Control plane provider's interaction with Cluster API is based on what is defined in the [Cluster API contract](#contract).
   168  
   169  See [KCP](#kcp).
   170  
   171  ### Core provider
   172  
   173  Refers to a [provider](#provider) that implements Cluster API core controllers; if you
   174  consider that the first project that must be deployed in a management Cluster is Cluster API itself, it should be clear why
   175  the Cluster API project is also referred to as the core provider.
   176  
   177  See [CAPI](#cluster-api).
   178  
   179  # D
   180  ---
   181  
   182  ### Default implementation
   183  
   184  A feature implementation offered as part of the Cluster API project and maintained by the CAPI core team; For example
   185  [KCP](#kcp) is a default implementation for a [control plane provider](#control-plane-provider).
   186  
   187  # E
   188  ---
   189  
   190  ### External patch
   191  
   192  [Patch](#patch) generated by an external component using [Runtime SDK](#runtime-sdk). Alternative to [inline patch](#inline-patch).
   193  
   194  ### External patch extension
   195  
   196  A [runtime extension](#runtime-extension) that implements a [topology mutation hook](#topology-mutation-hook).
   197  
   198  # H
   199  ---
   200  
   201  ### Horizontal Scaling
   202  
   203  The ability to add more machines based on policy and well-defined metrics. For example, add a machine to a cluster when CPU load average > (X) for a period of time (Y).
   204  
   205  ### Host
   206  
   207  see [Server](#server)
   208  
   209  # I
   210  ---
   211  
   212  ### Infrastructure provider
   213  
   214  Refers to a [provider](#provider) that implements provisioning of infrastructure/computational resources required by
   215  the Cluster or by Machines (e.g. VMs, networking, etc.).
   216  Infrastructure provider's interaction with Cluster API is based on what is defined in the [Cluster API contract](#contract).
   217  
   218  Clouds infrastructure providers include AWS, Azure, or Google; while VMware, MAAS, or metal3.io can be defined as bare metal providers.
   219  When there is more than one way to obtain resources from the same infrastructure provider (e.g. EC2 vs. EKS in AWS) each way is referred to as a variant.
   220  
   221  For a complete list of providers see [Provider Implementations](providers.md).
   222  
   223  ### Inline patch
   224  
   225  A [patch](#patch) defined inline in a [ClusterClass](#clusterclass). An alternative to an [external patch](#external-patch).
   226  
   227  ### In-place mutable fields
   228  
   229  Fields which changes would only impact Kubernetes objects or/and controller behaviour
   230  but they won't mutate in any way provider infrastructure nor the software running on it. In-place mutable fields
   231  are propagated in place by CAPI controllers to avoid the more elaborated mechanics of a replace rollout.
   232  They include metadata, MinReadySeconds, NodeDrainTimeout, NodeVolumeDetachTimeout and NodeDeletionTimeout but are
   233  not limited to be expanded in the future.
   234  
   235  ### Instance
   236  
   237  see [Server](#server)
   238  
   239  ### Immutability
   240  
   241  A resource that does not mutate.  In Kubernetes we often state the instance of a running pod is immutable or does not change once it is run.  In order to make a change, a new pod is run.  In the context of [Cluster API](#cluster-api) we often refer to a running instance of a [Machine](#machine) as being immutable, from a [Cluster API](#cluster-api) perspective.
   242  
   243  ### IPAM provider
   244  
   245  Refers to a [provider](#provider) that allows Cluster API to interact with IPAM solutions.
   246  IPAM provider's interaction with Cluster API is based on the `IPAddressClaim` and `IPAddress` API types.
   247  
   248  # K
   249  ---
   250  
   251  ### Kubernetes-conformant
   252  
   253  Or __Kubernetes-compliant__
   254  
   255  A cluster that passes the Kubernetes conformance tests.
   256  
   257  ### k/k
   258  
   259  Refers to the [main Kubernetes git repository](https://github.com/kubernetes/kubernetes) or the main Kubernetes project.
   260  
   261  ### KCP
   262  
   263  Kubeadm Control plane Provider
   264  
   265  # L
   266  ---
   267  
   268  ### Lifecycle hook
   269  A [Runtime Hook](#runtime-hook) that allows external components to interact with the lifecycle of a Cluster.
   270  
   271  See [Implementing Lifecycle Hooks](../tasks/experimental-features/runtime-sdk/implement-lifecycle-hooks.md)
   272  # M
   273  ---
   274  
   275  ### Machine
   276  
   277  Or __Machine Resource__
   278  
   279  The Custom Resource for Kubernetes that represents a request to have a place to run kubelet.
   280  
   281  See also: [Server](#server)
   282  
   283  ### Manage a cluster
   284  
   285  Perform create, scale, upgrade, or destroy operations on the cluster.
   286  
   287  ### Managed Kubernetes
   288  
   289  Managed Kubernetes refers to any Kubernetes cluster provisioning and maintenance abstraction, usually exposed as an API, that is natively available in a Cloud provider. For example: [EKS](https://aws.amazon.com/eks/), [OKE](https://www.oracle.com/cloud/cloud-native/container-engine-kubernetes/), [AKS](https://azure.microsoft.com/en-us/products/kubernetes-service), [GKE](https://cloud.google.com/kubernetes-engine), [IBM Cloud Kubernetes Service](https://www.ibm.com/cloud/kubernetes-service), [DOKS](https://www.digitalocean.com/products/kubernetes), and many more throughout the Kubernetes Cloud Native ecosystem.
   290  
   291  ### Managed Topology
   292  
   293  See [Topology](#topology)
   294  
   295  ### Management cluster
   296  
   297  The cluster where one or more Infrastructure Providers run, and where resources (e.g. Machines) are stored. Typically referred to when you are provisioning multiple workload clusters.
   298  
   299  ### Multi-tenancy
   300  
   301  Multi tenancy in Cluster API defines the capability of an infrastructure provider to manage different credentials, each
   302  one of them corresponding to an infrastructure tenant.
   303  
   304  Please note that up until v1alpha3 this concept had a different meaning, referring to the capability to run multiple
   305  instances of the same provider, each one with its own credentials; starting from v1alpha4 we are disambiguating the two concepts.
   306  
   307  See [Multi-tenancy](../developer/architecture/controllers/multi-tenancy.md) and [Support multiple instances](../developer/architecture/controllers/support-multiple-instances.md).
   308  
   309  # N
   310  ---
   311  
   312  ### Node pools
   313  
   314  A node pool is a group of nodes within a cluster that all have the same configuration.
   315  
   316  # O
   317  ---
   318  
   319  ### Operating system
   320  
   321  Or __OS__
   322  
   323  A generically understood combination of a kernel and system-level userspace interface, such as Linux or Windows, as opposed to a particular distribution.
   324  
   325  # P
   326  ---
   327  
   328  ### Patch
   329  
   330  A set of instructions describing modifications to a Kubernetes object. Examples include JSON Patch and JSON Merge Patch.
   331  
   332  ### Pivot
   333  
   334  Pivot is a process for moving the provider components and declared cluster-api resources from a Source Management cluster to a Target Management cluster.
   335  
   336  The pivot process is also used for deleting a management cluster and could also be used during an upgrade of the management cluster.
   337  
   338  ### Provider
   339  
   340  Or __Cluster API provider__
   341  
   342  This term was originally used as abbreviation for [Infrastructure provider](#infrastructure-provider), but currently it is used
   343  to refer to any project that can be deployed and provides functionality to the Cluster API management Cluster.
   344  
   345  See [Bootstrap provider](#bootstrap-provider), [Control plane provider](#control-plane-provider), [Core provider](#core-provider),
   346  [Infrastructure provider](#infrastructure-provider), [IPAM provider](#ipam-provider)  [Runtime extension provider](#runtime-extension-provider).
   347  
   348  ### Provider components
   349  
   350  Refers to the YAML artifact published as part of the release process for [providers](#provider);
   351  it usually includes Custom Resource Definitions (CRDs), Deployments (to run the controller manager), RBAC, etc.
   352  
   353  In some cases, the same expression is used to refer to the instances of above components deployed in a management cluster.
   354  
   355  See [Provider repository](#provider-repository)
   356  
   357  ### Provider repository
   358  
   359  Refers to the location where the YAML for [provider components](#provider-components) are hosted; usually a provider repository hosts
   360  many version of provider components, one for each released version.
   361  
   362  # R
   363  ---
   364  
   365  ### Runtime Extension
   366  
   367  An external component which is part of a system built on top of Cluster API that can handle requests for a specific Runtime Hook.
   368  
   369  See [Runtime SDK](#runtime-sdk)
   370  
   371  ### Runtime Extension provider
   372  
   373  Refers to a [provider](#provider) that implements one or more [runtime extensions](#runtime-extension).
   374  Runtime Extension provider's interaction with Cluster API are based on the Open API spec for [runtime hooks](#runtime-hook).
   375  
   376  ### Runtime Hook
   377  
   378  A single, well identified, extension point allowing applications built on top of Cluster API to hook into specific moments of the [Cluster API Runtime](#cluster-api-runtime), e.g. [BeforeClusterUpgrade](../tasks/experimental-features/runtime-sdk/implement-lifecycle-hooks.md#beforeclusterupgrade), [TopologyMutationHook](#topology-mutation-hook).
   379  
   380  See [Runtime SDK](#runtime-sdk)
   381  
   382  ### Runtime SDK
   383  
   384  A developer toolkit required to build Runtime Hooks and Runtime Extensions.
   385  
   386  See [Runtime SDK](../tasks/experimental-features/runtime-sdk/index.md)
   387  
   388  # S
   389  ---
   390  
   391  ### Scaling
   392  
   393  Unless otherwise specified, this refers to horizontal scaling.
   394  
   395  ### Stacked control plane
   396  
   397  A control plane node where etcd is colocated with the Kubernetes API server, and
   398  is running as a static pod.
   399  
   400  ### Server
   401  
   402  The infrastructure that backs a [Machine Resource](#machine), typically either a cloud instance, virtual machine, or physical host.
   403  
   404  # T
   405  ---
   406  
   407  ### Topology
   408  
   409  A field in the Cluster object spec that allows defining and managing the shape of the Cluster's control plane and worker machines from a single point of control. The Cluster's topology is based on a [ClusterClass](#clusterclass).
   410  Sometimes it is also referred as a managed topology.
   411  
   412  See [ClusterClass](#clusterclass)
   413  
   414  
   415  ### Topology Mutation Hook
   416  
   417  A [Runtime Hook](#runtime-hook) that allows external components to generate [patches](#patch) for customizing Kubernetes objects that are part of a [Cluster topology](#topology).
   418  
   419  See [Topology Mutation](../tasks/experimental-features/runtime-sdk/implement-topology-mutation-hook.md)
   420  
   421  # W
   422  ---
   423  
   424  ### Workload Cluster
   425  
   426  A cluster created by a ClusterAPI controller, which is *not* a bootstrap cluster, and is meant to be used by end-users, as opposed to by CAPI tooling.
   427  
   428  ### WorkerClass
   429  
   430  A collection of templates that define a set of worker nodes in the cluster. A ClusterClass contains zero or more WorkerClass definitions.
   431  
   432  See [ClusterClass](#clusterclass)