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Apache2 on Ubuntu

Enabling User Directory

This is how to set up Apache2 on Ubuntu so that, when hxxp://server/~username is accessed, the browser returns the content in /home/username/public_html.

First, user directory is now a mod in Ubuntu's apache2. If you have not installed the mod, then execute the following command:

sudo a2enmod userdir

Second, edit /etc/apache2/apache2.conf and add the following lines:

<IfModule mod_userdir.c>
    UserDir public_html
</IfModule>

<Directory /home/*/public_html>
    AllowOverride FileInfo AuthConfig Limit
    Options Indexes SymLinksIfOwnerMatch IncludesNoExec
</Directory>

Third, execute the following command:

cd /etc/apache2/mods-enabled
sudo ln -s /etc/apache2/mods-available/userdir.conf userdir.conf
sudo ln -s /etc/apache2/mods-available/userdir.load userdir.load

Forth, restart your apache2:

sudo /etc/init.d/apache2 restart

Installing Grader Web Interface

Installing HAML

The grader makes use of HAML. So you need to install it first.

gem install haml --no-ri

Checking out the Grader Web Interface

First, make a directory that will contain all the grader files. In my case, I make a directory called "grader" inside my home directory.

mkdir ~/grader

Inside the directory, you check out the web interface.

svn co http://theory.cpe.ku.ac.th/grader/web/trunk ~/grader/web

Setting up the Database

cd ~/grader/web/config
cp database.yml.SAMPLE database.yml

Then, edit database.yml so that it reflects the database setting of your machine.

Note: In Ubuntu, the database socket is not located at /tmp/mysql.sock as it is in other distributions. You need to add one extra line in database.yml to tell rails this:

 adapter: mysql
 socket: /var/run/mysqld/mysqld.sock
 database: ioi
 username: ioi
 password: whateverpassword
 host: localhost

Next, you do the migration:

cd ~/grader/web
rake db:migrate

Check your MySQL to see if the tables actually appear.

Test the Grader for the First Time

Then, run the server

ruby script/server

Go check http://localhost:3000. You can login as root and the password is ioionrails. You should change the password immediately and logout.

Judge

Judge system reads user submissions and test submissions and grades. It can be run with different configurations (called modes) depending on the situations, e.g., during the exam, the judge probably grades with example test cases but while grading it grades with different sets of test cases. This multiple configurations can be done with multiple modes where configured so that the judge finds different sets of test data.

Basic directory structure

/[judge-root]
  /ev                     (containing grading information for each problem)
    /problem_1
     ...
    /problem_n
    /test_request         (containing TEST interface template for each problem)
      /problem_1
      ...
      /problem_n
  /result                 (containing grading results)
    /user_1
      /problem_1
        /submission_1     
    ...
    /user_n
  /scripts                (where all script are)
    /config               (where all config files are)
    /lib         
    /std-script           (grading scripts)
    /templates            (used for importing scripts)
    /test
  /log

Judge modes

Currently there are 3 modes: exam, grading, and test. Only the first two are relevant to normal usage. The test mode is only used when the system runs its unit test scripts.

The main different between the exam mode and grading mode, other than having different locations for test cases, is on how the outputs from the grading are shown to the user. During the exam mode, the system is configured so that it only reports 'passed' or 'failed', but in grading mode, each result for each test case is shown.

How to install

Edit config files

Config files are in (judge-home)/scripts/config. In that, you will find sample config files (under *.SAMPLE).

• First you have to copy and edit environment.rb.
  • RAILS_ROOT --- The judge accesses submissions through Rails ActiveRecord; therefore, it has to run Rails' environment. You should set RAILS_ROOT to point to where the root of Rails application for the web interface is. (There is a drawback for this design: you have to install and configure the web interface even when you just want to run the judge system.)
  • GRADER_ROOT --- This is the directory where the scripts are. It should be (judge-home)/scripts/config. (Notes: This should actually read JUDGE_SCRIPT_ROOT, will fix it later ---Jittat 17:35, 16 มีนาคม 2008 (ICT))

• For each mode, you'll have to edit its configuration. For mode (MODE), configuration file will be env_(MODE).rb. Most configuration should work as it is, except that current both grading mode and exam mode are configured to share the same ev directory.

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