GlusterFS Native driver

GlusterFS Native driver uses GlusterFS, an open source distributed
file system, as the storage backend for serving file shares to manila
clients.

A manila share is a GlusterFS volume. This driver uses flat-network
(share-server-less) model. Instances directly talk with the GlusterFS
backend storage pool. The instances use ‘glusterfs’ protocol to mount
the GlusterFS shares. Access to each share is allowed via TLS
Certificates. Only the instance which has the TLS trust established with
the GlusterFS backend can mount and hence use the share. Currently only
‘rw’ access is supported.

Network Approach

L3 connectivity between the storage backend and the host running the
manila share service should exist.

Supported shared filesystems

• GlusterFS (share protocol: glusterfs, access by TLS
  certificates (cert access type))

Multi-tenancy model

The driver does not support network segmented multi-tenancy model.
Instead multi-tenancy is supported using tenant specific TLS
certificates.

Supported Operations

• Create share
• Delete share
• Allow share access (rw)
• Deny share access
• Create snapshot
• Delete snapshot
• Create share from snapshot

Requirements

• Install glusterfs-server package, version >= 3.6.x, on the
  storage backend.
• Install glusterfs and glusterfs-fuse package, version >=3.6.x, on
  the manila host.
• Establish network connection between the manila host and the storage
  backend.

Manila driver configuration
setting

The following parameters in manila’s configuration file need to be
set:

• share_driver =

  manila.share.drivers.glusterfs.glusterfs_native.GlusterfsNativeShareDriver

• glusterfs_servers = List of GlusterFS
  servers which provide volumes

  that can be used to create shares. The servers are expected to be of
  distinct Gluster clusters (ie. should not be gluster peers). Each server
  should be of the form
  [<remoteuser>@]<glustervolserver>.

  The optional <remoteuser>@ part of the server URI
  indicates SSH access for cluster management (see related optional
  parameters below). If it is not given, direct command line management is
  performed (ie. manila host is assumed to be part of the GlusterFS
  cluster the server belongs to).

• glusterfs_volume_pattern = Regular
  expression template

  used to filter GlusterFS volumes for share creation. The regex
  template can contain the #{size} parameter which matches a number
  (sequence of digits) and the value shall be interpreted as size of the
  volume in GB. Examples: manila-share-volume-\d+$,
  manila-share-volume-#{size}G-\d+$; with matching volume
  names, respectively: manila-share-volume-12,
  manila-share-volume-3G-13“. In latter example, the number that
  matches #{size}, that is, 3, is an indication that the size
  of volume is 3G.

The following configuration parameters are optional:

• glusterfs_mount_point_base = <base
  path of GlusterFS volume mounted on

  manila host>

• glusterfs_path_to_private_key =
  <path to manila host’s private key file>
• glusterfs_server_password =
  <password of remote GlusterFS server machine>

Host and backend
configuration

• SSL/TLS should be enabled on the I/O path for GlusterFS servers and
  volumes involved (ie. ones specified in glusterfs_servers),
  as described in https://docs.gluster.org/en/latest/Administrator%20Guide/SSL/.
  (Enabling SSL/TLS for the management path is also possible but not
  recommended currently.)
• The manila host should be also configured for GlusterFS SSL/TLS (ie.
  /etc/ssl/glusterfs.{pem,key,ca} files has
  to be deployed as the above document specifies).
• There is a further requirement for the CA-s used: the set of CA-s
  involved should be consensual, ie. /etc/ssl/glusterfs.ca should be identical
  across all the servers and the manila host.
• There is a further requirement for the common names (CN-s) of the
  certificates used: the certificates of the servers should have a common
  name starting with glusterfs-server, and
  the certificate of the host should have common name starting with manila-host.
• To support snapshots, bricks that consist the GlusterFS volumes used
  by manila should be thinly provisioned LVM ones (cf. https://gluster.readthedocs.org/en/latest/Administrator%20Guide/Managing%20Snapshots/).

Known Restrictions

• GlusterFS volumes are not created on demand. A pre-existing set of
  GlusterFS volumes should be supplied by the GlusterFS cluster(s),
  conforming to the naming convention encoded by
  glusterfs_volume_pattern. However, the GlusterFS endpoint
  is allowed to extend this set any time (so manila and GlusterFS
  endpoints are expected to communicate volume supply/demand out-of-band).
  glusterfs_volume_pattern can include a size hint (with
  #{size} syntax), which, if present, requires the GlusterFS
  end to indicate the size of the shares in GB in the name. (On share
  creation, manila picks volumes at least as big as the requested
  one.)
• Certificate setup (aka trust setup) between instance and storage
  backend is out of band of manila.
• For manila to use GlusterFS volumes, the name of the trashcan
  directory in GlusterFS volumes must not be changed from the
  default.

The
manila.share.drivers.glusterfs.glusterfs_native.GlusterfsNativeShareDriver
Module