Design doc of FlexVolume plugin driver

Change-Id: I9424cfd520b0ca6218e8790cf432392f2635a55e

README.rst

@@ -18,8 +18,3 @@ Make Kubernetes integration with OpenStack storage
 * Source: http://git.openstack.org/cgit/openstack/fuxi-kubernetes
 * Bugs: http://bugs.launchpad.net/fuxi-kubernetes
 * Blueprints: https://blueprints.launchpad.net/fuxi-kubernetes
-
-Features
---------
-
-* TODO

doc/source/devref/flex_volume_driver.rst

@@ -0,0 +1,46 @@
+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+FlexVolume Driver
+=================
+
+As the spec `[1]`_ introduced, FlexVolume `[2]`_ driver will implement the driver
+interfaces of FlexVolume plugin to enable Kubelet to consume persistent
+volumes. Each driver will be loaded when Kubelet starts and be used as
+the standalone FlexVolume plugin, which means that Kubelet may start
+several FlexVolume plugins and each plugin binds one driver.
+
+In Fuxi-kubernetes, FlexVolume driver consists of four components.
+
+.. figure:: ../../images/flex_volume_driver.png
+    :alt: FlexVolume Driver
+    :align: center
+
+1. **Driver**:
+FlexVolume plugin will communicate with driver by 'call-out'. So, for plguin,
+the driver should be an executable file which receives each command and
+returns corresponding results. For Cinder and Manila, there is a shell
+file for each of them to do this work respectively.
+
+2. **Server**:
+The real driver runs as a service and locates at the work node. It
+calls Cinder and Manila to supply volume for Pod.
+
+3. **Client**:
+'Driver' will pass the commands to 'Service' via 'Client'.
+
+4. **Host**:
+The driver runs on the node which may be baremetal or vitual machine.
+It needs to know the informations of work node to supply volume for Pod. 'Host'
+stands for the work node and supply relevant informations, such as host name,
+connector which is used to connect volumes.
+
+
+References
+----------
+_`[1]`: https://docs.openstack.org/developer/kuryr-kubernetes/specs/pike/fuxi_kubernetes.html
+
+_`[2]`: https://github.com/kubernetes/community/blob/master/contributors/devel/flexvolume.md

doc/source/devref/index.rst

@@ -0,0 +1,17 @@
+Developer Guide
+===============
+
+Flex Volume Driver
+------------------
+.. toctree::
+   :maxdepth: 2
+
+   flex_volume_driver
+
+Indices and tables
+------------------
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`
+

doc/source/index.rst

@@ -16,6 +16,13 @@ Using
    usage
    contributing
 
+Developer Guide
+===============
+.. toctree::
+   :maxdepth: 1
+
+   devref/index
+
 Indices and tables
 ==================