bind mount cvmfs directories with singcvmfs ?

[fwyzard]

Hi @DrDaveD,
I'm trying to set up singcvmfs on LUMI to make it as usable as possible.
Basic CVMFS operations work: I can list CMSSW releases from CVMFS, create a working area, run local workflows, etc.

Now I'm trying to get grid/voms proxies to work :-)

When CVMFS is available, the container images used by CMS bind-mount the grid certificates and voms configuration from /cvmfs/grid.cern.ch:

singularity exec --bind ...,/cvmfs,/cvmfs/grid.cern.ch/etc/grid-security/vomses:/etc/vomses,/cvmfs/grid.cern.ch/etc/grid-security:/etc/grid-security ...

Attempting a similar approach with singcvmfs reasonably fails:

singcvmfs exec --bind ...,/cvmfs/grid.cern.ch/etc/grid-security/vomses:/etc/vomses,/cvmfs/grid.cern.ch/etc/grid-security:/etc/grid-security ...
FATAL:   container creation failed: mount /cvmfs/grid.cern.ch/etc/grid-security/vomses->/etc/vomses error: while mounting /cvmfs/grid.cern.ch/etc/grid-security/vomses: mount source /cvmfs/grid.cern.ch/etc/grid-security/vomses doesn't exist

Trying to bind-mount once the container is running also fails:

mount --bind /cvmfs/grid.cern.ch/etc/grid-security/vomses /etc/vomses
mount: only root can use "--bind" option

So, is there a way to achieve the same effect with singcvmfs ?

[DrDaveD]

cvmfsexec can't currently do it but I'm planning on making a similar tool called bindexec that allows exactly that and is based on the cvmfsexec implementation. You're the third person to express a desire for that functionality. See also #100 (comment).