On Wed, Feb 18, 2015 at 10:28 PM, Oliver Schulz <osch...@mpp.mpg.de> wrote: > Dear Ceph Experts, > > is it possible to define a Ceph user/key with privileges > that allow for read-only CephFS access but do not allow > write or other modifications to the Ceph cluster?
Warning, read this to the end, don't blindly do as I say. :) All you should need to do is define a CephX identity that has only r capabilities on the data pool (assuming you're using a default configuration where your CephFS uses the data and metadata pools): sudo ceph auth get-or-create client.readonly mds 'allow' osd 'allow r pool=data' mon 'allow r' That identity should then be able to mount the filesystem but not write any data (use "ceph-fuse -n client.readonly" or "mount -t ceph -o name=readonly") That said, just touching files or creating them is only a metadata operation that doesn't change anything in the data pool, so I think that might still be allowed under these circumstances. However, I've just tried the above with ceph-fuse on firefly, and I was able to mount the filesystem that way and then echo something into a previously existing file. After unmounting, remounting, and trying to cat that file, I/O just hangs. It eventually does complete, but this looks really fishy. So I believe you've uncovered a CephFS bug. :) Cheers, Florian _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
