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Cindy Wang fedc513658 Consolidated examples into storage/ and volume/ folders Search and replace for references to moved examples Reverted find and replace paths on auto gen docs Reverting changes to changelog Fix bugs in test-cmd.sh Fixed path in examples README ran update-all successfully Updated verify-flags exceptions to include renamed files		2016-07-08 13:34:32 -07:00
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README.md	Consolidated examples into storage/ and volume/ folders	2016-07-08 13:34:32 -07:00
lvm	Consolidated examples into storage/ and volume/ folders	2016-07-08 13:34:32 -07:00
nginx.yaml	Consolidated examples into storage/ and volume/ folders	2016-07-08 13:34:32 -07:00

README.md

PLEASE NOTE: This document applies to the HEAD of the source tree

If you are using a released version of Kubernetes, you should refer to the docs that go with that version.

Documentation for other releases can be found at releases.k8s.io.

Flexvolume

Flexvolume enables users to mount vendor volumes into kubernetes. It expects vendor drivers are installed in the volume plugin path on every kubelet node.

It allows for vendors to develop their own drivers to mount volumes on nodes.

Note: Flexvolume is an alpha feature and is most likely to change in future

Prerequisites

Install the vendor driver on all nodes in the kubelet plugin path. Path for installing the plugin: /usr/libexec/kubernetes/kubelet-plugins/volume/exec/<vendor~driver>/<driver>

For example to add a 'cifs' driver, by vendor 'foo' install the driver at: /usr/libexec/kubernetes/kubelet-plugins/volume/exec/<foo~cifs>/cifs

Plugin details

Driver will be invoked with 'Init' to initialize the driver. It will be invoked with 'attach' to attach the volume and with 'detach' to detach the volume from the kubelet node. It also supports custom mounts using 'mount' and 'unmount' callouts to the driver.

Driver invocation model:

Init:

<driver executable> init

Attach:

<driver executable> attach <json options>

Detach:

<driver executable> detach <mount device>

Mount:

<driver executable> mount <target mount dir> <mount device> <json options>

Unmount:

<driver executable> unmount <mount dir>

See lvm[lvm] for a quick example on how to write a simple flexvolume driver.

Driver output:

Flexvolume expects the driver to reply with the status of the operation in the following format.

{
	"status": "<Success/Failure>",
	"message": "<Reason for success/failure>",
	"device": "<Path to the device attached. This field is valid only for attach calls>"
}

Default Json options

In addition to the flags specified by the user in the Options field of the FlexVolumeSource, the following flags are also passed to the executable.

"kubernetes.io/fsType":"<FS type>",
"kubernetes.io/readwrite":"<rw>",
"kubernetes.io/secret/key1":"<secret1>"
...
"kubernetes.io/secret/keyN":"<secretN>"

Example of Flexvolume

See nginx.yaml for a quick example on how to use Flexvolume in a pod.