Virtual Exam

Work in Progress or Draft only

Please read the documentation of virtual exam

The way the virtual exam white listed software (etc/vx.conf) will be rewritten early in Term 1 to better cope with software changes on CSE computers.

Useful scripts

• ~give/stable/bin/prac_install_vx [from_prac] to_prac
  • set up a standard virtual exam environment
  • if from_prac != to_prac
    • copy from_prac from virtual directory if exists
    • copy from_prac from gaol directory otherwise
  • else
    • copy from_prac from gaol directory
• priv passwd
  • change the vxN (eg vx6) password before and after the exam with this script
  • add the class account public key to the exam account (eg cs2521exam)

• priv chown <path_wildcard>

  • change work directory ownership from 90<uid> to the exam account to access students' files

  • after changing ownership, students can't start the exam. so, do this only after the exam has finished.
• /home/vxconf/vx.conf.d is the repository for vx.conf files for commonly used products e.g. gcc, python, gedit, fluxbox
  • prac-install-vx creates ~/exams/prac/etc/vx.conf.d and fill it with symbolic links to vx.conf files in /home/vxconf/vx.conf.d

    -rw-r--r-- 1 vxconf vxconf  433 Mar 14 21:31 000-header.conf
    -rw-r--r-- 1 vxconf vxconf  220 Mar 14 21:31 100-basicx.conf
    -rw-r--r-- 1 vxconf vxconf  159 Mar 14 21:31 100-fontconfig.conf
    -rw-r--r-- 1 vxconf vxconf   99 Mar 14 21:31 100-rxvt.conf
    -rw-r--r-- 1 vxconf vxconf  202 Mar 14 21:31 200-wm-fluxbox.conf
    -rw-r--r-- 1 vxconf vxconf  351 Mar 14 21:31 200-wm-fvwm.conf
    -rw-r--r-- 1 vxconf vxconf  608 Mar 14 21:31 300-interp-perl.conf
    -rw-r--r-- 1 vxconf vxconf  210 Mar 14 21:31 300-interp-pylint.conf
    -rw-r--r-- 1 vxconf vxconf 1894 Mar 14 21:31 300-interp-python.conf
    -rw-r--r-- 1 vxconf vxconf  860 Mar 14 21:31 300-toolchain-binutils.conf
    -rw-r--r-- 1 vxconf vxconf 3374 Mar 14 21:31 300-toolchain-clang.conf
    -rw-r--r-- 1 vxconf vxconf 1690 Mar 14 21:31 300-toolchain-gcc.conf
    -rw-r--r-- 1 vxconf vxconf  105 Mar 14 21:31 300-toolchain-gdb.conf
    -rw-r--r-- 1 vxconf vxconf   79 Mar 14 21:31 300-toolchain-make.conf
    -rw-r--r-- 1 vxconf vxconf  212 Mar 14 21:31 300-toolchain-valgrind.conf
    -rw-r--r-- 1 vxconf vxconf   84 Mar 14 21:31 400-browser-firefox.conf
    -rw-r--r-- 1 vxconf vxconf   54 Mar 14 21:31 400-browser-midori.conf
    -rw-r--r-- 1 vxconf vxconf  369 Mar 14 21:31 400-browser-nautilus.conf
    -rw-r--r-- 1 vxconf vxconf   84 Mar 14 21:31 400-viewer-evince.conf
    -rw-r--r-- 1 vxconf vxconf  110 Mar 14 21:31 400-viewer-xpdf.conf
    -rw-r--r-- 1 vxconf vxconf  328 Mar 14 21:31 500-editor-emacs.conf
    -rw-r--r-- 1 vxconf vxconf  300 Mar 14 21:31 500-editor-gedit.conf
    -rw-r--r-- 1 vxconf vxconf   52 Mar 14 21:31 500-editor-idle.conf
    -rw-r--r-- 1 vxconf vxconf   47 Mar 14 21:31 500-editor-nedit.conf
    -rw-r--r-- 1 vxconf vxconf   96 Mar 14 21:31 500-editor-spyder3.conf
    -rw-r--r-- 1 vxconf vxconf   26 Mar 14 21:31 500-editor-vi.conf
    -rw-r--r-- 1 vxconf vxconf  161 Mar 14 21:31 500-editor-vim.conf

    thanks to Jashank for the original idea

• ~give/stable/bin/vx-conf-product.pl
  • strace the command
  • feed the output of strace to this script
  • add vx.conf files as arguments
  • script will output files that are missing from the config files

Tips

• when the exam crashes after you authenticated with your zid, check the stderr.log file under <exam_account>/var directory. Look at the latest directories.

  marimba % ls -lt ~/var | head -5
  total 988
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 13 06:59 marimba-25528
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 12 20:49 wagner-7800
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 12 20:33 vx4-45795
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 12 18:39 vx4-34624

• after changing ownership of the work directories (to exam account), you can't start the exam with the same work directories.
  • create a new toplevel work directory.

    cd ~/exams/18s2supp
    mv work work.19dec
    mkdir work
    chmod 1777 work

  • or remove the student's work directory

    cd ~/exams/18s2supp/work
    priv chown z5555555
    rm -r z5555555