/Praktomat

quality control for programming assignments

Primary LanguagePythonGNU General Public License v2.0GPL-2.0

This is the source distribution of Praktomat, a programming course manager.

Resources

In case of bugs or feature requests, please use the Bug tracker. There is also a moderated mailing list for Praktomat administrators: praktomat-users@lists.kit.edu.

A note about Python 2

Since pip will drop support for Python 2 in January 2020, we don't support Python 2 any more. But at time of writing that note, you can use Praktomat with Python 2.

Python 3.5

The Praktomat currently requires Python 3.5

On Ubuntu 16.04, Python3.5 is installed by default, but you may need to install the packages

python-setuptools
python-psycopg2
python-virtualenv

General setup

You need the latest version that is compatible with the Python version used. We also highly recommend to use virtualenv so your system Python installation remains clean.

If you are having trouble with

pip install

and get a No matching distribution found or Could not fetch URL error, try adding -v to the command to get more information:

pip install --upgrade -v pip

If you see an error like There was a problem confirming the ssl certificate or tlsv1 alert protocol version or TLSV1_ALERT_PROTOCOL_VERSION, you need to be connecting to PyPI with a newer TLS support library.

Reason: PyPI turned off support for TLS versions 1.0 and 1.1 in April 2018 https://pyfound.blogspot.com/2017/01/time-to-upgrade-your-python-tls-v12.html

To fix this, it might help to run the following command:

pip install -U pip virtualenv setuptools wheel urllib3[secure]

Prerequisites: Database and Webserver

We recommend to run Praktomat within Apache, using PostgreSQL as database management system.

On a Debian or Ubuntu System, install the packages

postgresql
apache2-mpm-worker         (<= Ubuntu 14)
apache2
libapache2-mod-macro       (<= Ubuntu 14, removed in Ubuntu 16)
libapache2-mod-wsgi        (for using with Python2)
libapache2-mod-wsgi-py3    (for using with Python3)
libapache2-mod-xsendfile   (version 0.12; or install version 1.0 manually)
apache2-dev                (used by pip while installing mod_wsgi)

Pitfalls while Systemupgrades

In Ubuntu 16 the package apache2-mpm-worker has been merged into apache2. Before upgrading to Ubuntu 16 or higher and you are in Ubuntu 14 or lower versions, than you have to edit

/var/lib/apt/extended_state

there change entry

Package: apache2
Architecture: amd64
Auto-Installed: 1

to

Auto-Installed: 0

If you don't change that value, apache2 package becomes deleted while upgrading Ubuntu.

Prerequisites: 3rd-Party libraries and programms

Praktomat requires some 3rd-Party libraries programs to run. On a Ubuntu/Debian System, these can be installed by installing the following packages:

util-linux
libpq-dev
zlib1g-dev
libmysqlclient-dev (or: default-libmysqlclient-dev)
libsasl2-dev
libssl-dev
libffi-dev
openssl (for signing E-Mails)
swig

openjdk-11-jdk (or: openjdk-8-jdk)
junit
junit4
dejagnu

git-core

libldap2-dev (if you want to use python-ldap==2.3.13 for connecting to ldap)

r-base

If youre going to use Praktomat to check Haskell submissions, you will also require the packages:

ghc libghc-test-framework-dev libghc-test-framework-hunit-dev libghc-test-framework-quickcheck2-dev

For Checkstyle, we recommend getting checkstyle-all-4.4.jar or checkstyle-8.14-all.jar

https://github.com/checkstyle/checkstyle/releases/

Documentation for checkstyle please see: https://checkstyle.org/

If you want your users to submit Isabelle theories, add the following line to /etc/mime.types:

text/x-isabelle thy

Some words of folder layout to Developer, Testing and Deployment-Setup

We have changed the folder layout, to keep repository-folders clean. The name PraktomatSupport was ambiguous to us, so we change it. => Folders for UPLOAD_ROOT and SANDBOX_DIR and STATIC_ROOT changed.

Python variable UPLOAD_ROOT points to debug-data, test-data or work-data dependig on manage-devel.py, manage-test.py or manage-local.py.

Python variable SANDBOX_DIR points to a folder inside UPLOAD_ROOT.

Semester folder:

.
  |-Praktomat   <= this is only the repository
  |  |-documentation
  |  |-media
  |  |-examples
  |  |-src
  |  |-docker-image
  |  |-wsgi
  |-static
  |-debug-data
  |  |-CheckerFiles
  |  |-SolutionArchive
  |  |-SolutionSandbox
  |-work-data
  |  |-CheckerFiles
  |  |-SolutionArchive
  |  |-SolutionSandbox
  |-test-data
  |  |-CheckerFiles
  |  |-SolutionArchive
  |  |-SolutionSandbox

In some files there are information that you have to change for your need:

Praktomat/src/settings/devel.py
Praktomat/src/settings/local.py
Praktomat/src/settings/test.py
Praktomat/src/checker/scripts/cTestrunner
Praktomat/src/checker/scripts/junit.policy

You can deactivate checkers and compilers in your local Praktomat instance, just comment them out in src/checker/checker/__init__.py and src/checker/checker/__init__.py. Do not forget to create and run a django migration in that case.

If you exchange Praktomat-Tasks (export and import) than the instance, which is used to import the task, must have activated all needed checkers and compilers which are configured in the that task.

Developer and Tester setup

Clone this repo and install the required python libs to either your system-wide Python installation or inside a designated virtualenv (recommended). The following describes a recommended setup using virtualenv.

git clone --recursive git://github.com/KITPraktomatTeam/Praktomat.git
virtualenv -p python3 --system-site-packages env/
. env/bin/activate
pip install -U pip virtualenv setuptools wheel urllib3[secure]
pip install -r Praktomat/requirements.txt

The initial database setup follows. In standard development configuration Praktomat/src/settings/devel.py and in configuration Praktomat/src/settings/test.py for running django unit tests against Praktomat the databases are SQLite files.

  • 'UPLOAD_ROOT+/Database+PRAKTOMAT_ID' for development
  • 'UPLOAD_ROOT+/DjangoTestDatabase+PRAKTOMAT_ID' for unittesting which are created by python on the fly.
cd Praktomat
mkdir ../debug-data/
./src/manage-devel.py migrate --noinput
./src/manage-devel.py createsuperuser

Start the development server.

./src/manage-devel.py runserver

or

pip install Werkzeug
./src/manage-devel.py runserver_plus

to run django unit tests

cd Praktomat
mkdir ../test-data/
./src/manage-test.py test accounts attestation checker configuration solutions tasks hbrs_tests

Deployment installation

Like for the development version, clone the Praktomat and install its dependencies:

git clone --recursive git://github.com/KITPraktomatTeam/Praktomat.git
virtualenv -p python3 --system-site-packages env/
. env/bin/activate
pip install -U pip virtualenv setuptools wheel urllib3[secure]
pip install -r Praktomat/requirements.txt

Now create a database. Using postgres on Ubuntu, this might work for creating a database "praktomat_<PRAKTOMAT_ID>". Also edit pg_hba.conf to allow the access. Your database-system should be configured to UTF-8.

sudo -u postgres createuser -DRS praktomat
sudo -u postgres createdb --encoding UTF8 -O praktomat praktomat_<PRAKTOMAT_ID>

The postfix <PRAKTOMAT_ID> of database name in above creation statement have to reflect the value of the python variable PRAKTOMAT_ID in Praktomat/src/settings/local.py.

Configure Praktomat in Praktomat/src/settings/local.py, which contains all settings and paths for your deployment system, too.

Create the upload directory, populate the database:

cd Praktomat
mkdir ../work-data/
./Praktomat/src/manage-local.py collectstatic --noinput --link
./Praktomat/src/manage-local.py migrate --noinput

It should now be possible to start the deployment server with:

./Praktomat/src/manage-local.py runserver

If you want to deploy the project using mod_wsgi in apache you could use documentation/apache_praktomat_wsgi.conf as a starting point. Don't forget to install mod_xsendfile to serve uploaded files.

And if your Praktomat running on apache should handle non-ASCII filenames correctly, than the easyest way is activating UTF-8 support inside apache. Debian runs Apache with the LANG=C locale by default, which breaks uploading files with special characters in their names at least when running with mod_wsgi. Activating a UTF-8 locale in /etc/apache2/envvars should resolve the issue. ( see https://code.djangoproject.com/ticket/6009#comment:18 )

Adding the first user

If you use django for authentification, you might want to add a first user using

./Praktomat/src/manage-local.py createsuperuser

If you use single-sign-on via Shibboleth, you can already log in. After you have logged in, you can assign super user rights to yourself using

./Praktomat/src/manage-local.py makesuperuser --username=<the_user_name>

The username is visible under “View Account”; by default it is the e-mail address submitted by the Shibboleth server.

Update

  1. update the source with git from github

  2. backup your database (seriously!)

  3. update the static files and the database: a) If you want to reuse your current database entries, you have to ensure, that the name of the database inside settings files fits to your needs. b) Folders for UPLOAD_ROOT and SANDBOX_DIR and STATIC_ROOT changed with "merge marathon" in February 2022.

./Praktomat/src/manage-local.py makemigrations
./Praktomat/src/manage-local.py migrate --noinput
./Praktomat/src/manage-local.py collectstatic --noinput --link

Security

Besides the security provided by Java (via the Security Manager Profiles found in src/checker/scripts/), the praktomat supports two way to insulate student submissions from the system:

  • With USEPRAKTOMATTESTER = True in the settings, external commands are prefixed with sudo -u tester --. For this to work you need to add a user tester which is also a member of the default group of the user that runs the praktomat (usually praktomat).

  • With USESAFEDOCKER = True, external commands are prefixed with safe-docker, which you need to have installed. You can fetch it from http://github.com/nomeata/safe-docker

    For this to work you need to have a docker image named safe-docker installed, which needs to have all required dependencies installed. A suggested docker image is available in docker-image, so to get started simply run

     sudo docker build -t safe-docker docker-image

We recommend USESAFEDOCKER, as that is what we test in practice.

The Praktomat tries to limit the resources available to the student submissions:

  • The runtime of the submission can be limited (setting TEST_TIMEOUT)
  • The maximum amount of memory used can be limited (setting TEST_MAXMEM, only supported with USESAFEDOCKER).
  • The maximum size of a file produced by a user submission (setting TEST_MAXFILESIZE, currently not supported with USESAFEDOCKER, until http://stackoverflow.com/questions/25789425 is resolved)

At the time of writing, the amount of diskspace available to the user is unlimited, which can probably be exploited easily.

jPlag integration

Praktomat provides a rudimentary, but convenient integration of the plagiarism detection program jPlag. Do enable this support, you have to do these two steps:

  • Download the latest jPlag release (latest tested version: v2.12.1)
  • Copy the resulting .jar file somewhere on the Praktomat server.
  • In the settings, set JPLAGJAR = /full/path/to/jplag.jar

PhpBB integration

To access the praktomat usersessions from an phpBB follow the instructions in src/sessionprofile/phpbb/README.txt.

CUnit CPPUnit Checker

For configuration please have a look into README_feature_CUnitCppUnit_Checker.txt.