[gridengine users] How to export an X11 back to the client?
Mun.Johl at wdc.com
Thu May 7 18:29:05 UTC 2020
Hi William, et al.,
Thank you kindly for your response and insight.
Please see my comments below.
> On Wed, May 06, 2020 at 11:10:40PM +0000, Mun Johl wrote:
> > [Mun] In order to use ssh -X for our jobs that require an X11 window to be pushed to a user's VNC display, I am planning on the
> following changes. But please let me know if I have missed something (or everything).
> > 1. Update the global configuration with the following parameters:
> > rsh_command /usr/bin/ssh -X
> > rsh_daemon /usr/sbin/sshd -i
> As you are using the pam_sge-qrsh-setup.so you will need to set
> rsh_daemon to point to a rshd-wrapper which you should find in
> $SGE_ROOT/util/resources/wrappers eg if $SGE_ROOT is /opt/sge
> rsh_command /usr/bin/ssh -X
> rsh_daemon /opt/sge/util/resources/wrappers/rshd-wrapper
[Mun] Thanks for pointing out my mistake!
> > 2. Use a PAM module to attach an additional group ID to sshd. The following line will be added to /etc/pam.d/sshd on all SGE
> > auth required /opt/sge/lib/lx-amd64/pam_sge-qrsh-setup.so
> > 3. Do I need to restart all of the SGE daemons at this point?
> No it should be fine without a restart
> > 4. In order to run our GUI app, launch it thusly:
> > $ qrsh -now no wrapper.tcl
> That looks fine, assuming sensible default resource requests, although
> obviously I don't know the details of the wrapper or application.
[Mun] After making the above changes, I'm still experiencing problems. First, let me point out that I should have more accurately represented how qrsh will be used:
$ qrsh -now no <other qrsh options> tclsh wrapper.tcl <options for wrapper script>
Now for the issues:
I first added the pam_sge-qrsh-setup.so at the top of the /etc/pam.d/sshd file. When I did that the qrsh job was launched but quickly terminated with the following error from the tool I was attempting to launch:
The connection to SimVision could not be established due to an error
in SimVision. Check your DISPLAY environment variable,
which may be one of the reasons for this error.
I am not explicitly setting the DISPLAY--as that is how I normally use 'ssh -X'. Nor have I done anything to open any additional ports. Again, since 'ssh -X' is working for us. As a reminder, there is no way for me to know what to set DISPLAY to even if I wanted to set it.
Now, the /etc/pam.d/sshd update caused an ssh issue: Users could no longer ssh into our servers :( I didn't realize the order of the lines in the sshd is significant.
Therefore, I moved the pam_sge-qrsh-setup.so entry below the other "auth" lines. Although, that resulted in the following error when I tried the qrsh command again:
Your "qrsh" request could not be scheduled, try again later.
One final note is that we have "selinux" enabled on our servers. I don't know if that makes any difference, but I thought I'd throw it out there.
Feedback would be most welcome.
More information about the users