[Condor-users] Customizing the environment the job runs in

[Terrence Martin <tmartin@xxxxxxxxxxxxxxxx>]

Hi,

I am investigating what I can and cannot do to customize the environment 
that my condor jobs execute in.

I have jobs coming in via some gateway. The gateway takes care of 
authentication, generates a Condor command file and submits it to 
condor. The job goes to the compute node and before it runs some 
environment components need to be set up;

Chroot the environment
Mount key directories via a file system capable of remapping UID/GID 
(eg. SMB/CIFS)
Create any necessary local links to files on the gateway node (the 
gateway software allows remote reading of some state files)
Allow the job to execute

The jobs are running in the vanilla universe but the UID/GID remapping 
is done on the fly. Most of the work is done by a wrapper I am writing. 
However for some things the wrapper might be too late. The problem I am 
running into is that part of the startup of the condor job includes 
trying to open two files, one for STDIN, the other for STDERR. These two 
files may not be "writable" at the time condor checks them, but they 
will be at some point before the job starts up. The problem is the jobs 
may fail to start since these files are not readable before my wrapper 
runs.

One idea I had was to turn off the "checking" of the stdin/stderr files. 
That is to just start the job even if they are not writeable since they 
will be later. Is this possible? The other option might be to "fake" the 
output files in the command script for condor and then try to reconnect 
things with the wrapper. That is not use absolute, but relative paths 
for the logs, then try to link them back to the logs that will actually 
be updated (and available externally through the gateway).

Can I turn off the output file checking?

Thanks,

Terrence