[sage-support] permission denied for .png files in /tmp when using server pool

[Kyle VonBlohn]

Hi,

My apologies if this has been answered elsewhere, as I have searched, but 
have not found anything related to this specific problem.

I have a sage server (6.4.1) running on Ubuntu 14.04 amd64.  I used 
instructions found here: http://wiki.sagemath.org/SageServer by Jason 
Grout, and here: https://help.ubuntu.com/community/SAGE on the ubuntu wiki. 
 I have everything setup as specified, i.e. rsa keys so that user 
sageserver can ssh into sage*@localhost without a password, and have 
created a directory /sagenb with ownership sageserver:sageuser (where 
sageuser is the group to which the server_pool accounts and sageserver 
belong) and permissions of 775.

What I am experiencing is that when using the server pool, calculations in 
the notebook work as expected, i.e. 2+2 returns 4 when shift-enter is 
pressed.  However, any commands where a png is created and returned, such 
as plot(cos,(-5,5)), evaluate but are not displayed.  when I check the 
server console, I am seeing the following:

2015-02-16 11:32:36-0500 [HTTPChannel,7,<ipaddress>] Error copying file 
from worksheet process: [Errno 13] Permission denied: 
'/tmp/tmp4juuwE/sage0.png'

looking further, i see this:

root@Sage:/home/ladmin# ls -la /tmp/tmp4juuwE/
total 44
drwxrwxrwx 2 sageserver sageserver  4096 Feb 16 11:32 .
drwxrwxrwt 7 root       root        4096 Feb 16 11:33 ..
-rw-r--r-- 1 sage3      sageuser     132 Feb 16 11:32 ___code___.py
lrwxrwxrwx 1 sageserver sageserver    43 Feb 16 11:32 data -> 
/sagenb/nbfiles.sagenb/home/kvonbloh/0/data
-rw------- 2 sage3      sageuser   26589 Feb 16 11:32 sage0.png
-rw-rw-r-- 1 sageserver sageserver   370 Feb 16 11:32 _sage_input_2.py
root@Sage:/home/ladmin#

it appears the .png file created by the "worker" process has permissions of 
600.  so when sageserver attempts to copy it from the tmp directory back 
into the worksheet, it cannot read the file.  If I remove the server_pool 
line from my startnotebook script and it runs with only the single account, 
everything works fine and images are displayed in the worksheet as expected.

Any idea what I may be missing?  we would like to implement sage for our 
mathematics courses here at the university, but i suspect when we have 60+ 
users working on it simultaneously, running it with the single user process 
will severely impact performance.  I am new to sage, so any help would be 
appreciated.

Thanks,
Kyle

-- 
You received this message because you are subscribed to the Google Groups 
"sage-support" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to sage-support+unsubscr...@googlegroups.com.
To post to this group, send email to sage-support@googlegroups.com.
Visit this group at http://groups.google.com/group/sage-support.
For more options, visit https://groups.google.com/d/optout.