The optional instructions below are suggestions for the system administrators of a live Submitty installation.
Customize upload students script
The system admin or instructor can upload student data from either an XLSX or CSV spreadsheet of their student classlist (obtained from the university registrar).
sudo ./bin/setcsvfields W X Y Z
Since the format of this data may vary between universities, this command allows customization of what columns from the spreadsheet represent students first name (W), last name (X), campus e-mail (Y), and registration Section ID (Z).
For example: If the students’ first name is column 13, last name is column 12, e-mail is column 15, and section ID is column 7, then the command is:
sudo ./bin/setcsvfields 13 12 15 7
Schedule backups of production server data
Specifically, the configuration, submission, and results data for all courses:
And the central location of the student SVN repositories (if used):
You may want to back up more of
/var/local/submitty to save configurations and logs, but be sure to exclude
/var/local/submitty/to_be_graded_batch and to_be_graded_interactive
Capture cron error messages
hwcron user runs the bin/grade_students.sh
script. STDERR output from this script should be logged or emailed
to ensure that system errors can be reported and addressed.
See cron job details in INSTALL_SUBMITTY_template.sh.
Configure log rotation
The defaults will work, but you may want to keep records around for longer and enable compression so that the logs don’t take up as much space. Edit /etc/logrotate.conf and change the log rotation, retention, and compression settings to suit your situation. The comments in the file will tell you what each setting is for, or see logrotate(8) for more details.
Set password policy
It is a good idea to enforce strong passwords and password aging
/etc/login.defs to set default password and account expiration
and set the umask to block world readable/writable files by default
(search for the keywords and update the values after them)
UMASK 027 PASS_MAX_DAYS 730 PASS_MIN_DAYS 0 PASS_WARN_AGE 30
Apply settings by running:
Accept the defaults from the above command.
/etc/pam.d/common-password to tweak settings under the line:
# here are the per-package modules (the "Primary" block)
along the lines of:
password requisite pam_passwdqc.so min=disabled,disabled,15,12,12 similar=deny enforce=everyone retry=3
Note: The values after min= correspond to password length minimum if they contain: a single character class, 2 classes, a passphrase, 3 classes, 4 classes.
Note: If you would like to allow local machine passwords for pam authentication, make sure the hwcgi user is in the shadow group.
We encourage you to edit
/etc/ssh/sshd_config to use only stronger encryption sets along the lines of:
Protocol 2 MACs hmac-sha1,email@example.com,hmac-ripemd160 Ciphers aes256-ctr,aes192-ctr,aes128-ctr,arcfour256,arcfour128
Block some brute-force ssh connections by typing the following at a command prompt:
sudo bash iptables -I INPUT -p tcp --dport 22 -m state --state NEW -m recent --set iptables -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --update --seconds 60 --hitcount 8 -j DROP iptables-save > /root/eth0.fw exit
/etc/rc.local to automatically reload the software
firewall on boot and add the following just before the
/sbin/iptables-restore < /root/eth0.fw
Note: This method may not be appropriate or may need to be tuned if you normally expect a lot of ssh connections from a given host. You may also opt to whitelist addresses or networks that are allowed to connect more frequently.
Disable PHP Functions
To improve the security of the system, it might be useful to disable various unused PHP functions. This can be done by modifying the disabled_functions directive. Provided below is the setting used within our Vagrant and live setup:
However, this should be only applied to the
php.ini running the web server and not applied to the
cgi/php.ini which does require some of these functions to function properly.
Allowing Large Student File Upload Submissions
By default, Apache / Ubuntu limits the size of file upload by POST to 10MB. To increase this edit:
Change these variables as appropriate:
And restart apache:
sudo systemctl restart apache2.service sudo systemctl restart php7.0-fpm.service
sudo service apache2 restart sudo service php7.0-fpm restart
By default, a Submitty electronic gradeable allows students to upload
files totaling 100KB. Instructors can adjust this limit per gradeable
config.json, for example:
// 1 mb maximum submission size "max_submission_size" : 1000000
If you are having difficulty with student upload size, you can modify the following in /etc/php/7.0/fpm/php.ini:
Just be aware that modifying this number can have repercussions when multiple students are using the system at once.