mirror of
https://github.com/ceph/ceph
synced 2024-12-27 05:53:20 +00:00
f788686d5c
Fixes: http://tracker.ceph.com/issues/19075 Signed-off-by: John Spray <john.spray@redhat.com>
130 lines
4.4 KiB
ReStructuredText
130 lines
4.4 KiB
ReStructuredText
================================
|
||
CephFS Client Capabilities
|
||
================================
|
||
|
||
Use Ceph authentication capabilities to restrict your filesystem clients
|
||
to the lowest possible level of authority needed.
|
||
|
||
.. note::
|
||
|
||
Path restriction and layout modification restriction are new features
|
||
in the Jewel release of Ceph.
|
||
|
||
Path restriction
|
||
================
|
||
|
||
By default, clients are not restricted in what paths they are allowed to mount.
|
||
Further, when clients mount a subdirectory, e.g., /home/user, the MDS does not
|
||
by default verify that subsequent operations
|
||
are ‘locked’ within that directory.
|
||
|
||
To restrict clients to only mount and work within a certain directory, use
|
||
path-based MDS authentication capabilities.
|
||
|
||
Syntax
|
||
------
|
||
|
||
To grant rw access to the specified directory only, we mention the specified
|
||
directory while creating key for a client following the undermentioned syntax. ::
|
||
|
||
./ceph auth get-or-create client.*client_name* mon 'allow r' mds 'allow r, allow rw path=/*specified_directory*' osd 'allow rw pool=data'
|
||
|
||
for example, to restrict client ``foo`` to writing only in the ``bar`` directory,
|
||
we will use: ::
|
||
|
||
./ceph auth get-or-create client.foo mon 'allow r' mds 'allow r, allow rw path=/bar' osd 'allow rw pool=data'
|
||
|
||
To completely restrict the client to the ``bar`` directory, omit the
|
||
unqualified "allow r" clause: ::
|
||
|
||
./ceph auth get-or-create client.foo mon 'allow r' mds 'allow rw path=/bar' osd 'allow rw pool=data'
|
||
|
||
Note that if a client's read access is restricted to a path, they will only
|
||
be able to mount the filesystem when specifying a readable path in the
|
||
mount command (see below).
|
||
|
||
|
||
See `User Management - Add a User to a Keyring`_. for additional details on user management
|
||
|
||
To restrict a client to the specfied sub-directory only, we mention the specified
|
||
directory while mounting following the undermentioned syntax. ::
|
||
|
||
./ceph-fuse -n client.*client_name* *mount_path* -r *directory_to_be_mounted*
|
||
|
||
for example, to restrict client ``foo`` to ``mnt/bar`` directory, we will use. ::
|
||
|
||
./ceph-fuse -n client.foo mnt -r /bar
|
||
|
||
Free space reporting
|
||
--------------------
|
||
|
||
By default, when a client is mounting a sub-directory, the used space (``df``)
|
||
will be calculated from the quota on that sub-directory, rather than reporting
|
||
the overall amount of space used on the cluster.
|
||
|
||
If you would like the client to report the overall usage of the filesystem,
|
||
and not just the quota usage on the sub-directory mounted, then set the
|
||
following config option on the client:
|
||
|
||
::
|
||
|
||
client quota df = false
|
||
|
||
If quotas are not enabled, or no quota is set on the sub-directory mounted,
|
||
then the overall usage of the filesystem will be reported irrespective of
|
||
the value of this setting.
|
||
|
||
OSD restriction
|
||
===============
|
||
|
||
To prevent clients from writing or reading data to pools other than
|
||
those in use for CephFS, set an OSD authentication capability that
|
||
restricts access to the CephFS data pool(s):
|
||
|
||
::
|
||
|
||
client.0
|
||
key: AQAz7EVWygILFRAAdIcuJ12opU/JKyfFmxhuaw==
|
||
caps: [mds] allow rw
|
||
caps: [mon] allow r
|
||
caps: [osd] allow rw pool=data1, allow rw pool=data2
|
||
|
||
.. note::
|
||
|
||
Without a corresponding MDS path restriction, the OSD capabilities above do
|
||
**not** restrict file deletions outside of the ``data1`` and ``data2``
|
||
pools.
|
||
|
||
You may also restrict clients from writing data by using 'r' instead of
|
||
'rw' in OSD capabilities. This does not affect the ability of the client
|
||
to update filesystem metadata for these files, but it will prevent them
|
||
from persistently writing data in a way that would be visible to other clients.
|
||
|
||
Layout and Quota restriction (the 'p' flag)
|
||
===========================================
|
||
|
||
To set layouts or quotas, clients require the 'p' flag in addition to 'rw'.
|
||
This restricts all the attributes that are set by special extended attributes
|
||
with a "ceph." prefix, as well as restricting other means of setting
|
||
these fields (such as openc operations with layouts).
|
||
|
||
For example, in the following snippet client.0 can modify layouts and quotas,
|
||
but client.1 cannot.
|
||
|
||
::
|
||
|
||
client.0
|
||
key: AQAz7EVWygILFRAAdIcuJ12opU/JKyfFmxhuaw==
|
||
caps: [mds] allow rwp
|
||
caps: [mon] allow r
|
||
caps: [osd] allow rw pool=data
|
||
|
||
client.1
|
||
key: AQAz7EVWygILFRAAdIcuJ12opU/JKyfFmxhuaw==
|
||
caps: [mds] allow rw
|
||
caps: [mon] allow r
|
||
caps: [osd] allow rw pool=data
|
||
|
||
|
||
.. _User Management - Add a User to a Keyring: ../../rados/operations/user-management/#add-a-user-to-a-keyring
|