Re: [HTCondor-users] Submitting and refreshing X509_USER_PROXY

[Zach Miller <zmiller@xxxxxxxxxxx>]

Hi Lukas,


HTCondor can automatically delegate GSI credentials to the execute node.  In your submit file just specify:
   x509UserProxy = /tmp/x509up_u<uid>

Delegating is better than transferring because the proxy is then not transmitted over the wire.  HTCondor will also then update the proxy on the execute machine if it changes on the submit machine.  No need for a wrapper script.  Details on that here:
  http://research.cs.wisc.edu/htcondor/manual/v8.7/condor_submit.html#97602


Also, a VERY important issue is that if you are running all jobs as nobody, one job would be able to see another jobs sandbox (and therefore potentially steal the proxy from that job, which may be from a different user).

Instead of "nobody", you should use "slot users".  Details on that can be found here:
  http://research.cs.wisc.edu/htcondor/manual/v8.7/3_8Security.html#sec:RunAsNobody

This will isolate each job with its own UID so they cannot examine or interfere with each other.


Please let me know if you have any further questions!


Cheers,
-zach


> -----Original Message-----
> From: HTCondor-users <htcondor-users-bounces@xxxxxxxxxxx> On Behalf Of
> Koschmieder, Lukas
> Sent: Wednesday, April 25, 2018 11:57 AM
> To: HTCondor-Users Mail List <htcondor-users@xxxxxxxxxxx>
> Subject: [HTCondor-users] Submitting and refreshing X509_USER_PROXY
> 
> Hi,
> 
> My scheduler and execute nodes are located in different networks. Therefore
> there is neither a shared filesystem nor a common UID domain available. All
> jobs have to run as nobody user.
> 
> I've enable GSI auth in Condor and set up two file servers that provide GSI
> auth support (Globus-GridFTP and XRootD). Now I'd like to enable Condor
> jobs to use the job owner's GSI credentials to access the GSI file servers.
> (The final goal is to dynamically auto-mount a user's XRootD working
> directory (input/output folder) on the execute nodes when a job starts -
> preferably inside the scratch directory.) I could use TRANSFER_INPUT_FILES
> to manually copy a user's local X509_USER_PROXY to the execute nodes and
> then use USER_JOB_WRAPPER to refresh that X509_USER_PROXY. I was wondering
> if there is a better / less hacky way to do that.
> 
> Best regards,
> Lukas
> 
> 
> 
> --
> Lukas Koschmieder
> Steel Institute IEHK
> RWTH Aachen University
> Intzestraße 1
> 52072 Aachen
> Germany