[slurm-users] x11 forwarding not available?

Tue Oct 16 07:30:13 MDT 2018

Hrm... it looks like the default install of OHPC went with DHA keys
instead:

.ssh]$ cat config 
# Added by Warewulf  2018-10-08
Host *
   IdentityFile ~/.ssh/cluster
   StrictHostKeyChecking=no
$ file cluster
cluster: PEM DSA private key

Now I have to find where that's configured since it autocreates those on
user login.

On Tue, Oct 16, 2018 at 03:12:42PM +0200, Olivier Sallou wrote:
> 
> 
> On 10/16/2018 03:04 PM, Jeffrey Frey wrote:
> > Make sure you're using RSA keys in users' accounts -- we'd started setting-up ECDSA on-cluster keys as we built our latest cluster but libssh at that point didn't support them.  And since the Slurm X11 plugin is hard-coded to only use ~/.ssh/id_rsa, that further tied us to RSA.  It would be nice for the host and user key files to be configurable options; more configurable options for that plugin in general would be useful.
> 
> and rsa key needs to be password-less (a shame...)
> >
> >
> >
> >
> >> On Oct 16, 2018, at 4:47 AM, Tina Friedrich <tina.friedrich at it.ox.ac.uk> wrote:
> >>
> >> I had an issue getting x11 forwarding via SLURM (srun/sbatch) to work; ssh 
> >> worked fine. Tracked it down to the host name setting on the nodes; as per 
> >> RedHat/CentOS default, the hostname was set to the fully qualified. Turns out 
> >> SLURMs X11 forwarding doesn't work with that; setting the hostnames to the 
> >> short hostname made it all magically work. 
> >>
> >> Tina
> >>
> >> On Tuesday, 16 October 2018 09:29:01 BST Olivier Sallou wrote:
> >>> On 10/16/2018 01:07 AM, Dave Botsch wrote:
> >>>> Hi.
> >>>>
> >>>> X11 forwarding is enabled and works for normal ssh.
> >>> I faced same issue, with ssh x11 working as expected on compute nodes,
> >>> but not with slurm -x11.
> >>>
> >>> I patched slurm locally to make it work.
> >>>
> >>> what you can try to see if it is the same issue:
> >>>
> >>>
> >>> srun -n1 --pty --x11 --pty bash
> >>>
> >>>
> >>> # xterm
> >>> // you should have an authorization failure error
> >>>
> >>> // on connected node
> >>> # xauth list
> >>>
> >>> you will have a list of MAGIC COOKIE like
> >>>
> >>> myslurmmaster/unix:10  MIT-MAGIC-COOKIE-1  YYYYYY
> >>> myslurmnode/unix:52  MIT-MAGIC-COOKIE-1  XXXXXX
> >>>
> >>> # echo $DISPLAY
> >>> localhost:52.0
> >>>
> >>>
> >>> To make it work manually I did (of course adapting node names and
> >>> display port number):
> >>>
> >>> xauth remove myslurmnode/unix:52
> >>> xauth add localhost:52.0
> >>>
> >>> then xterm (for example) worked.
> >>>
> >>> If this is the same problem, slurm can be easilly patched to work (can
> >>> give you how)
> >>>
> >>> Olivier
> >>>
> >>>> Thanks.
> >>>>
> >>>> On Mon, Oct 15, 2018 at 09:55:59PM +0000, Rhian Resnick wrote:
> >>>>> Double check /etc/ssh/sshd_config allows X11 forwarding on the node as it
> >>>>> is disable by default. (I think)
> >>>>>
> >>>>>
> >>>>> X11Forwarding yes
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>> Rhian Resnick
> >>>>>
> >>>>> Associate Director Research Computing
> >>>>>
> >>>>> Enterprise Systems
> >>>>>
> >>>>> Office of Information Technology
> >>>>>
> >>>>>
> >>>>> Florida Atlantic University
> >>>>>
> >>>>> 777 Glades Road, CM22, Rm 173B
> >>>>>
> >>>>> Boca Raton, FL 33431
> >>>>>
> >>>>> Phone 561.297.2647
> >>>>>
> >>>>> Fax 561.297.0222
> >>>>>
> >>>>> [image] <https://hpc.fau.edu/wp-content/uploads/2015/01/image.jpg>
> >>>>>
> >>>>> ________________________________
> >>>>> From: slurm-users <slurm-users-bounces at lists.schedmd.com> on behalf of
> >>>>> Dave Botsch <botsch at cnf.cornell.edu> Sent: Monday, October 15, 2018 5:51
> >>>>> PM
> >>>>> To: slurm-users at lists.schedmd.com
> >>>>> Subject: [slurm-users] x11 forwarding not available?
> >>>>>
> >>>>>
> >>>>>
> >>>>> Wanted to test X11 forwarding. X11 forwarding works as a normal user
> >>>>> just ssh'ing to a node and running xterm/etc.
> >>>>>
> >>>>> With srun, however:
> >>>>>
> >>>>> srun -n1 --pty --x11 xterm
> >>>>> srun: error: Unable to allocate resources: X11 forwarding not available
> >>>>>
> >>>>> So, what am I missing?
> >>>>>
> >>>>> Thanks.
> >>>>>
> >>>>> PS
> >>>>>
> >>>>> srun --version
> >>>>> slurm 17.11.7
> >>>>>
> >>>>> rpm -qa |grep slurm
> >>>>> ohpc-slurm-server-1.3.5-8.1.x86_64
> >>>>> ...
> >>>>>
> >>>>>
> >>>>> --
> >>>>> ********************************
> >>>>> David William Botsch
> >>>>> Programmer/Analyst
> >>>>> @CNFComputing
> >>>>> botsch at cnf.cornell.edu
> >>>>> ********************************
> >>>>> --
> >>>>> ********************************
> >>>>> David William Botsch
> >>>>> Programmer/Analyst
> >>>>> @CNFComputing
> >>>>> botsch at cnf.cornell.edu
> >>>>> ********************************
> >>
> >> -- 
> >> Tina Friedrich, Snr HPC Systems Administrator, Advanced Research Computing
> >> Research Computing and Support Services, Academic IT 
> >> IT Services, University of Oxford 
> >> http://www.arc.ox.ac.uk
> >>
> >
> > ::::::::::::::::::::::::::::::::::::::::::::::::::::::
> > Jeffrey T. Frey, Ph.D.
> > Systems Programmer V / HPC Management
> > Network & Systems Services / College of Engineering
> > University of Delaware, Newark DE  19716
> > Office: (302) 831-6034  Mobile: (302) 419-4976
> > ::::::::::::::::::::::::::::::::::::::::::::::::::::::
> >
> >
> >
> >
> >
> 
> -- 
> Olivier Sallou
> Univ Rennes, Inria, CNRS, IRISA
> Irisa, Campus de Beaulieu
> F-35042 RENNES - FRANCE
> Tel: 02.99.84.71.95
> 
> gpg key id: 4096R/326D8438  (keyring.debian.org)
> Key fingerprint = 5FB4 6F83 D3B9 5204 6335  D26D 78DC 68DB 326D 8438
> 
> 

-- 
********************************
David William Botsch
Programmer/Analyst
@CNFComputing
botsch at cnf.cornell.edu
********************************