.. _shared_file_systems_network_plugins:

================
Network plug-ins
================

The Shared File Systems service architecture defines an abstraction layer for
network resource provisioning and allowing administrators to choose from a
different options for how network resources are assigned to their projects’
networked storage. There are a set of network plug-ins that provide a variety
of integration approaches with the network services that are available with
OpenStack.

The Shared File Systems service may need a network resource provisioning if
share service with specified driver works in mode, when a share driver manages
lifecycle of share servers on its own. This behavior is defined by a flag
``driver_handles_share_servers`` in share service configuration.  When
``driver_handles_share_servers`` is set to ``True``, a share driver will be
called to create share servers for shares using information provided within a
share network. This information will be provided to one of the enabled network
plug-ins that will handle reservation, creation and deletion of network
resources including IP addresses and network interfaces.

What network plug-ins are available?
------------------------------------

There are three different network plug-ins and five python classes in the
Shared File Systems service:

#. Network plug-in for using the OpenStack Networking service. It allows to use
   any network segmentation that the Networking service supports. It is up to
   each share driver to support at least one network segmentation type.

   a) ``manila.network.neutron.neutron_network_plugin.NeutronNetworkPlugin``.
      This is a default network plug-in. It requires the ``neutron_net_id`` and
      the ``neutron_subnet_id`` to be provided when defining the share network
      that will be used for the creation of share servers. The user may define
      any number of share networks corresponding to the various physical
      network segments in a project environment.

   b) ``manila.network.neutron.neutron_network_plugin.
      NeutronSingleNetworkPlugin``. This is a simplification of the previous
      case. It accepts values for ``neutron_net_id`` and ``neutron_subnet_id``
      from the ``manila.conf`` configuration file and uses one network for all
      shares.

   When only a single network is needed, the NeutronSingleNetworkPlugin (1.b)
   is a simple solution. Otherwise NeutronNetworkPlugin (1.a) should be chosen.

#. Network plug-in for working with OpenStack Networking from the Compute
   service. It supports either flat networks or VLAN-segmented networks.

   a) ``manila.network.nova_network_plugin.NovaNetworkPlugin``. This plug-in
      serves the networking needs when ``Nova networking`` is configured in
      the cloud instead of Neutron. It requires a single parameter,
      ``nova_net_id``.

   b) ``manila.network.nova_network_plugin.NovaSingleNetworkPlugin``. This
      plug-in works the same way as
      ``manila.network.nova_network_plugin.NovaNetworkPlugin``, except it takes
      ``nova_net_id`` from the Shared File Systems service configuration
      file and creates the share servers using only one network.

   When only a single network is needed, the NovaSingleNetworkPlugin (2.b) is a
   simple solution. Otherwise NovaNetworkPlugin (2.a) should be chosen.

#. Network plug-in for specifying networks independently from OpenStack
   networking services.

   a) ``manila.network.standalone_network_plugin.StandaloneNetworkPlugin``.
      This plug-in uses a pre-existing network that is available to the
      manila-share host. This network may be handled either by OpenStack or be
      created independently by any other means. The plug-in supports any type
      of network - flat and segmented. As above, it is completely up to the
      share driver to support the network type for which the network plug-in is
      configured.

.. note::

   These network plug-ins were introduced in the OpenStack Kilo release. In
   the OpenStack Juno version, only NeutronNetworkPlugin is available.

More information about network plug-ins can be found in `Manila developer documentation <https://docs.openstack.org/developer/manila/adminref/network_plugins.html>`_