edbaskerville.com

After confirmation that things seem to work for others on Leopard, I went through and tried to make sure it would work on Tiger again too. I don’t have time to set up a Tiger test box right now, so I’d appreciate it someone who has a Tiger box would test this updated version:

XgridLite.prefPane.zip

Post your success/lack thereof in the comments!

After debugging some weirdness, I have a version of XgridLite that works on Leopard, I think. Brave testers, download this file:

XgridLite.prefPane.zip

Then decompress and drag the prefPane into your /Library/PreferencePanes or ~/Library/PreferencePanes

Let me know how it goes!

FYI, the weirdness I ran into goes something like this (as described in a message I just sent to the xgrid-users mailing list):

Hi everyone (particularly Apple folks),

After being out of the loop for a while, I finally got around to getting XgridLite working on Leopard. (Test version about to be posted at code.edbaskerville.com, official release probably by Monday.)

In doing so, I ran into one weirdness that I thought someone might be able to explain. XgridLite simply calls xgridctl to get and set controller state, which seems simple enough. In Tiger, it was sufficient to do this as root using a setuid tool.

In Leopard, however, I found that status calls always returned that the controller was off:

daemon              state               pid
======              =====               ===
xgridcontrollerd    stopped

This was happening inside the setuid tool even when querying it via sudo as a regular user worked fine:

Agnos:~ ebaskerv$ sudo xgridctl c status
daemon              state               pid
======              =====               ===
xgridcontrollerd    running             12656

To get to the bottom of this, I activated the root user on my system and tried it from a root shell, and, sure enough, I’m being told the controller is stopped:

sh-3.2# xgridctl c status
daemon              state               pid
======              =====               ===
xgridcontrollerd    stopped

Miraculously, though, if you run xgridctl via sudo as root, all is fine:

sh-3.2# sudo xgridctl c status
daemon              state               pid
======              =====               ===
xgridcontrollerd    running             12656

This gave me the workaround I needed: run xgridctl via sudo as root inside XgridLite. But I still have no idea *why* this is happening, so I’m writing purely out of curiosity. Why is it that running xgridctl status via sudo gives the correct status, while running as root directly does not? One more wrinkle: running xgridctl c start/stop seem to work fine inside my setuid tool (WITHOUT running via sudo), but do NOT work via a root shell!

Any wisdom would be appreciated.

Thanks,
Ed

As it turns out, the privilege failure mentioned in the last post was not being reported by the calls to xgridctl to start and stop the controller, but rather the ones that were trying to simply get what the current status was. In Leopard, you always need to run xgridctl as root, even just to get status.

However, when I recoded the status-getting code to use the privileged tool to do its work, it’s reporting that the controller is off when doing xgridctl c status at the command line reports that it’s running. One more roadblock, but this should be the last one. Given how my weeks go, it probably won’t be until next weekend (a long one, fall break).

To those who have been requesting that XgridLite start working on Leopard: first of all, sorry it’s taken so long for me to think about it. I didn’t even upgrade myself to Leopard until the middle of this year, and since then I’ve been pretty busy working, touring with my band, and finally starting a new life as an ecology grad student. The good news is that being a grad student means I’ll be running simulations again soon, so I’m selfishly motivated to have a working XgridLite on my machine.

I finally popped open the code after a long hiatus and tried it out. I was hoping the problem would just be a simple problem like the controller argument syntax changed, but I got this message in the console log:

ERROR: you must be running with root privileges

This is the same message you get when you run xgridctl c start as a regular user from the command line. So the mechanism I used to run as root under Tiger is clearly not working under Leopard. Perhaps this is related to the new security mechanisms (which I know nothing about) that Apple added.

I’ll try to tackle this tomorrow.