-
Notifications
You must be signed in to change notification settings - Fork 14.4k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
CRD versioning Public Documentation (#8834)
* CRD versioning Public Documentation * Copyedit Signed-off-by: Misty Stanley-Jones <mistyhacks@google.com> * Address feedback * More rewrites * Address feedback * Update main CRD page in light of versioning * Reorg CRD docs * Further reorg * Tweak title
- Loading branch information
1 parent
b715200
commit 71bf468
Showing
9 changed files
with
265 additions
and
22 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
5 changes: 5 additions & 0 deletions
5
content/en/docs/tasks/access-kubernetes-api/custom-resources/_index.md
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,5 @@ | ||
| --- | ||
| title: "Use Custom Resources" | ||
| weight: 10 | ||
| --- | ||
|
|
201 changes: 201 additions & 0 deletions
201
...access-kubernetes-api/custom-resources/custom-resource-definition-versioning.md
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,201 @@ | ||
| --- | ||
| title: Versions of CustomResourceDefinitions | ||
| reviewers: | ||
| - mbohlool | ||
| - sttts | ||
| - liggitt | ||
| content_template: templates/task | ||
| weight: 30 | ||
| --- | ||
|
|
||
| {{% capture overview %}} | ||
| This page explains how to add versioning information to | ||
| [CustomResourceDefinitions](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#customresourcedefinition-v1beta1-apiextensions), to indicate the stability | ||
| level of your CustomResourceDefinitions. It also describes how to upgrade an | ||
| object from one version to another. | ||
|
|
||
| {{< note >}} | ||
| **Note**: All specified versions must use the same schema. The is no schema | ||
| conversion between versions. | ||
| {{< /note >}} | ||
|
|
||
| {{% /capture %}} | ||
|
|
||
| {{% capture prerequisites %}} | ||
|
|
||
| {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}} | ||
|
|
||
| * Make sure your Kubernetes cluster has a master version of 1.11.0 or higher. | ||
|
|
||
| * Read about [custom resources](/docs/concepts/api-extension/custom-resources/). | ||
|
|
||
| {{% /capture %}} | ||
|
|
||
| {{% capture steps %}} | ||
|
|
||
| ## Overview | ||
|
|
||
| The CustomResourceDefinition API supports a `versions` field that you can use to | ||
| support multiple versions of custom resources that you have developed, and | ||
| indicate the stability of a given custom resource. All versions must currently | ||
| use the same schema, so if you need to add a field, you must add it to all | ||
| versions. | ||
|
|
||
| {{< note >}} | ||
| Earlier iterations included a `version` field instead of `versions`. The | ||
| `version` field is deprecated and optional, but if it is not empty, it must | ||
| match the first item in the `versions` field. | ||
| {{< /note >}} | ||
|
|
||
| ## Specify multiple versions | ||
|
|
||
| This example shows a CustomResourceDefinition with two versions. The comments in | ||
| the YAML provide more context. | ||
|
|
||
| ```yaml | ||
| apiVersion: apiextensions.k8s.io/v1beta1 | ||
| kind: CustomResourceDefinition | ||
| metadata: | ||
| # name must match the spec fields below, and be in the form: <plural>.<group> | ||
| name: crontabs.example.com | ||
| spec: | ||
| # group name to use for REST API: /apis/<group>/<version> | ||
| group: example.com | ||
| # list of versions supported by this CustomResourceDefinition | ||
| versions: | ||
| - name: v1beta1 | ||
| # Each version can be enabled/disabled by Served flag. | ||
| served: true | ||
| # One and only one version must be marked as the storage version. | ||
| storage: true | ||
| - name: v1 | ||
| served: true | ||
| storage: false | ||
| # either Namespaced or Cluster | ||
| scope: Namespaced | ||
| names: | ||
| # plural name to be used in the URL: /apis/<group>/<version>/<plural> | ||
| plural: crontabs | ||
| # singular name to be used as an alias on the CLI and for display | ||
| singular: crontab | ||
| # kind is normally the CamelCased singular type. Your resource manifests use this. | ||
| kind: CronTab | ||
| # shortNames allow shorter string to match your resource on the CLI | ||
| shortNames: | ||
| - ct | ||
| ``` | ||
| You can save the CustomResourceDefinition in a YAML file, then use | ||
| `kubectl create` to create it. | ||
|
|
||
| ```shell | ||
| kubectl create -f my-versioned-crontab.yaml | ||
| ``` | ||
|
|
||
| After creation, the API server starts to serve each enabled version at an HTTP | ||
| REST endpoint. In the above example, the API versions are available at | ||
| `/apis/example.com/v1beta1` and `/apis/example.com/v1`. | ||
|
|
||
| ### Version priority | ||
|
|
||
| Regardless of the order in which versions are defined in a | ||
| CustomResourceDefinition, the version with the highest priority is used by | ||
| kubectl as the default version to access objects. The priority is determined | ||
| by parsing the _name_ field to determine the version number, the stability | ||
| (GA, Beta, or Alpha), and the sequence within that stability level. | ||
|
|
||
| The algorithm used for sorting the versions is designed to sort versions in the | ||
| same way that the Kubernetes project sorts Kubernetes versions. Versions start with a | ||
| `v` followed by a number, an optional `beta` or `alpha` designation, and | ||
| optional additional versioning information. Broadly, a version string might look | ||
| like `v2` or `v2beta1`. Versions are sorted using the following algorithm: | ||
|
|
||
| - Entries that follow Kubernetes version patterns are sorted before those that | ||
| do not. | ||
| - For entries that follow Kubernetes version patterns, the numeric portions of | ||
| the version string is sorted largest to smallest. | ||
| - If the strings `beta` or `alpha` follow the first numeric portion, they sorted | ||
| in that order, after the equivalent string without the `beta` or `alpha` | ||
| suffix (which is presumed to be the GA version). | ||
| - If another number follows the `beta`, or `alpha`, those numbers are also | ||
| sorted from largest to smallest. | ||
| - Strings that don't fit the above format are sorted alphabetically and the | ||
| numeric portions are not treated specially. Notice that in the example below, | ||
| `foo1` is sorted above `foo10`. This is different from the sorting of the | ||
| numeric portion of entries that do follow the Kubernetes version patterns. | ||
|
|
||
| This might make sense if you look at the following sorted version list: | ||
|
|
||
| ```none | ||
| - v10 | ||
| - v2 | ||
| - v1 | ||
| - v11beta2 | ||
| - v10beta3 | ||
| - v3beta1 | ||
| - v12alpha1 | ||
| - v11alpha2 | ||
| - foo1 | ||
| - foo10 | ||
| ``` | ||
|
|
||
| For the example in [Specify multiple versions](#specify-multiple-versions), the | ||
| version sort order is `v1`, followed by `v1beta1`. This causes the kubectl | ||
| command to use `v1` as the default version unless the provided object specifies | ||
| the version. | ||
|
|
||
| ## Writing, reading, and updating versioned CustomResourceDefinition objects | ||
|
|
||
| When an object is written, it is persisted at the version designated as the | ||
| storage version at the time of the write. If the storage version changes, | ||
| existing objects are never converted automatically. However, newly-created | ||
| or updated objects are created at the new storage version. It is possible for an | ||
| object to have been written at a version that is no longer served. | ||
|
|
||
| When you read an object, you specify the version as part of the path. If you | ||
| specify a version that is different from the object's persisted version, | ||
| Kubernetes returns the object to you at the version you requested, but does not | ||
| modify the persisted object. You can request an object at any version that is | ||
| currently served. | ||
|
|
||
| If you update an existing object, it is rewritten at the version that is | ||
| currently the storage version. This is the only way that objects can change from | ||
| one version to another. | ||
|
|
||
| To illustrate this, consider the following hypothetical series of events: | ||
|
|
||
| 1. The storage version is `v1beta`. You create an object. It is persisted in | ||
| storage at version `v1beta1` | ||
| 2. You add version `v1` to your CustomResourceDefinition and designate it as | ||
| the storage version. | ||
| 3. You read your object at version `v1beta`, then you read the object again at | ||
| version `v1`. Both returned objects are identical except for the apiVersion | ||
| field. | ||
| 4. You create a new object. It is persisted in storage at version `v1`. You now | ||
| have two objects, one of which is at `v1beta`, and the other of which is at | ||
| `v1`. | ||
| 5. You update the first object. It is now persisted at version `v1` since that | ||
| is the current storage version. | ||
|
|
||
| ### Previous storage versions | ||
|
|
||
| The API server records each version which has ever been marked as the storage | ||
| version in the status field `storedVersions`. Objects may have been persisted | ||
| at any version that has ever been designated as a storage version. No objects | ||
| can exist in storage at a version that has never been a storage version. | ||
|
|
||
| ## Upgrade existing objects to a new stored version | ||
|
|
||
| When deprecating versions and dropping support, devise a storage upgrade | ||
| procedure. The following is an example procedure to upgrade from `v1beta1` | ||
| to `v1`. | ||
|
|
||
| 1. Set `v1` as the storage in the CustomResourceDefinition file and apply it | ||
| using kubectl. The `storedVersions` is now `v1beta1, v1`. | ||
| 2. Write an upgrade procedure to list all existing objects and write them with | ||
| the same content. This forces the backend to write objects in the current | ||
| storage version, which is `v1`. | ||
| 3. Update the CustomResourceDefinition `Status` by removing `v1beta1` from | ||
| `storedVersions` field. | ||
|
|
||
| {{% /capture %}} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.