Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. Introduce new `VolumeAttachment` API Object **What this PR does / why we need it**: Introduce a new `VolumeAttachment` API Object. This object will be used by the CSI volume plugin to enable external attachers (see design [here](https://github.com/kubernetes/community/pull/1258). In the future, existing volume plugins can be refactored to use this object as well. **Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: Part of issue https://github.com/kubernetes/features/issues/178 **Special notes for your reviewer**: None **Release note**: ```release-note NONE ```
Kubernetes's OpenAPI Specification
This folder contains an [OpenAPI specification][openapi] for Kubernetes API.
Vendor Extensions
Kuberntes extends OpenAPI using these extensions. Note the version that extensions has been added.
x-kubernetes-group-version-kind
Operations and Definitions may have x-kubernetes-group-version-kind if they
are associated with a kubernetes resource.
For example:
"paths": {
    ...
    "/api/v1/namespaces/{namespace}/pods/{name}": {
        ...
        "get": {
        ...
            "x-kubernetes-group-version-kind": {
            "group": "",
            "version": "v1",
            "kind": "Pod"
            }
        }
    }
}
x-kubernetes-action
Operations and Definitions may have x-kubernetes-action if they
are associated with a kubernetes resource.
Action can be one of get, list, put, patch, post, delete, deletecollection, watch, watchlist, proxy, or connect.
For example:
"paths": {
    ...
    "/api/v1/namespaces/{namespace}/pods/{name}": {
        ...
        "get": {
        ...
            "x-kubernetes-action": "list"
        }
    }
}
x-kubernetes-patch-strategy and x-kubernetes-patch-merge-key
Some of the definitions may have these extensions. For more information about PatchStrategy and PatchMergeKey see [strategic-merge-patch] (https://github.com/kubernetes/community/blob/master/contributors/devel/strategic-merge-patch.md).