Introduction

This app provides an "exam" app that lets users take an online programming quiz. Currently only Python and simple Bash scripts can be tested. At FOSSEE, Nishanth had implemented a nice django based app to test for multiple-choice questions. However, I was inspired by a programming contest that I saw at PyCon APAC 2011. Chris Boesch, who administered the contest, used a nice web application that he had built on top of GAE that basically checked your Python code, live. This made it fun and interesting. Their application can be seen at http://singpath.com

I wanted an implementation that was not tied to GAE and decided to write one myself and the result is the "exam" app. The idea being that I can use this to test students programming skills and not have to worry about grading their answers myself and I can do so on my machines.

You can define fairly complicated programming problems and have users solve the problem and the solution is checked immediately. The system supports pretty much arbitrary Python and uses "test cases" to test the implementations of the students. It also supports simple bash scripts -- see the sample questions in "docs/". In addition it supports simple multiple choice questions. Since it runs on your Python, you could technically test any Python based library. It is distributed under the BSD license.

It can use a lot more work but the basics work and the app scales to over 500+ simultaneous users. :)

Production Deployment

Pre-Requisite

1. Install MySql Server
2. Install Python MySql support
3. Install Apache Server for deployment

Configure MySql server

1. Create a database named online_test by following the steps below
   1. $> mysql -u root -p
   2. mysql> create database online_test
2. Add a user named online_test_user and give access to it on the database online_test by following the steps below
   1. mysql> grant usage on online_test.* to online_test_user@localhost identified by 'mysecretpassword';
   2. mysql> grant all privileges on online_test.* to online_test_user@localhost;
3. Create a file named local.py in folder testapp and insert DATABASE_PASSWORD = 'mysecretpassword'

To deploy this app follow the steps below:

1. Clone this repository and cd to the cloned repo.

2. run:

   python bootstrap.py
   

3. run:

   ./bin/buildout -c production.cfg
   

4. run:

   ./bin/django syncdb
   

   run:

   ./bin/django migrate exam
   

5. Add questions by editing the "docs/sample_questions.py" or any other file in the same format and then run the following:

   ./bin/django load_exam docs/sample_questions.py
   
      Note that you can supply multiple Python files as arguments and all of
      those will be added to the database.
   

6. First run the python server provided. This ensures that the code is executed in a safe environment. Do this like so:

   $ sudo python testapp/code_server.py
   

   Put this in the background once it has started since this will not return back the prompt. It is important that the server be running before students start attempting the exam. Using sudo is necessary since the server is run as the user "nobody". This runs on the ports configured in the settings.py file in the variable "SERVER_PORTS". The "SERVER_TIMEOUT" also can be changed there. This is the maximum time allowed to execute the submitted code. Note that this will likely spawn multiple processes as "nobody" depending on the number of server ports specified.

7. The bin/django.wsgi script should make it

   easy to deploy this using mod_wsgi. You will need to add a line of the form:

   WSGIScriptAlias / "/var/www/online_test/bin/django.wsgi"

   to your apache.conf. For more details see the Django docs here:

   https://docs.djangoproject.com/en/1.3/howto/deployment/modwsgi/

8. Go to http://desired_host_or_ip:desired_port/admin

9. Login with your credentials and look at the questions and modify if needed. Create a new Quiz, set the date and duration or activate/deactivate the quiz.

10. Now ask users to login at:

    http://host:port/exam

    And you should be all set.

11. Note that the directory "output" will contain directories, one for each user. Users can potentially write output into these that can be used for checking later.

12. As admin user you can visit http://host/exam/monitor to view

    results and user data interactively. You could also "grade" the papers manually if needed.

13. You may dump the results and user data using the results2csv and

    dump_user_data commands.

14. The file docs/sample_questions.py is a template that you can use for your own questions.

15. Sometimes you might be in the situation where you are not hosted as "host.org/exam/" but as "host.org/foo/exam/" for whatever reason. In this case edit "settings.py" and set the "URL_ROOT" to the root you have to serve at. In the above example for "host.org/foo/exam" set URL_ROOT='/foo'.

Development Settings

To install this app follow the steps below:

1. Clone this repository and cd to the cloned repo.

2. run:

   python bootstrap.py
   

3. run:

   ./bin/buildout -c buildout.cfg
   

4. run:

   ./bin/django syncdb
   

   run:

   ./bin/django migrate exam
   

5. Add questions by editing the "docs/sample_questions.py" or any other file in the same format and then run the following:

   ./bin/django load_exam docs/sample_questions.py
   

   Note that you can supply multiple Python files as arguments and all of those will be added to the database.

6. First run the python server provided. This ensures that the code is executed in a safe environment. Do this like so:

   $ sudo python testapp/code_server.py
   

   Put this in the background once it has started since this will not return back the prompt. It is important that the server be running before students start attempting the exam. Using sudo is necessary since the server is run as the user "nobody". This runs on the ports configured in the settings.py file in the variable "SERVER_PORTS". The "SERVER_TIMEOUT" also can be changed there. This is the maximum time allowed to execute the submitted code. Note that this will likely spawn multiple processes as "nobody" depending on the number of server ports specified.

7. Now, run:

   $ ./bin/django runserver <desired_ip>:<desired_port>
   

8. Go to http://deserved_host_or_ip:desired_port/admin

9. Login with your credentials and look at the questions and modify if needed. Create a new Quiz, set the date and duration or activate/deactivate the quiz.

10. Now ask users to login at:

    http://host:port/exam

    And you should be all set.

11. Note that the directory "output" will contain directories, one for each user. Users can potentially write output into these that can be used for checking later.

12. As admin user you can visit http://host/exam/monitor to view

    results and user data interactively. You could also "grade" the papers manually if needed.

13. You may dump the results and user data using the results2csv and

    dump_user_data commands.

14. The file docs/sample_questions.py is a template that you can use for your own questions.

15. Sometimes you might be in the situation where you are not hosted as "host.org/exam/" but as "host.org/foo/exam/" for whatever reason. In this case edit "settings.py" and set the "URL_ROOT" to the root you have to serve at. In the above example for "host.org/foo/exam" set URL_ROOT='/foo'.

Additional commands available

We provide several convenient commands for you to use:

• load_exam : load questions and a quiz from a python file. See docs/sample_questions.py
• load_questions_xml : load questions from XML file, see docs/sample_questions.xml use of this is deprecated in favor of load_exam.
• results2csv : Dump the quiz results into a CSV file for further processing.
• dump_user_data : Dump out relevalt user data for either all users or specified users.

For more information on these do this:

$ ./manage.py help [command]

where [command] is one of the above.

License

This is distributed under the terms of the BSD license. Copyright information is at the bottom of this file.

Authors

Main author: Prabhu Ramachandran

I gratefully acknowledge help from the following:

• Nishanth Amuluru originally from FOSSEE who wrote bulk of the login/registration code. He wrote an initial first cut of a quiz app which supported only simple questions which provided motivation for this app. The current codebase does not share too much from his implementation although there are plenty of similarities.
• Harish Badrinath (FOSSEE) -- who provided a first cut of the bash related scripts.
• Srikant Patnaik and Thomas Stephen Lee, who helped deploy and test the code.

Copyright (c) 2011 Prabhu Ramachandran and FOSSEE (fossee.in)