Installing Grader Web Interface

Return to ฐานความรู้

The aim of this document is to set up the grader's web interface rails application so that users can access it via http://your-web-server/grader. The application uses mongrel_cluster as its load balancer.

Install dependencies

The grader makes use of HAML and RSpec. You also need BlueCloth if you want nice formatting for tasks. So you need to install them first.

gem install haml --no-ri
gem install rspec --no-ri
gem install BlueCloth --no-ri

Check 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

Create routes.rb

cd ~/grader/web/config
cp routes.rb.SAMPLE routes.rb

Set 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.

Set up Mongrel Cluster

We assume that you already have mongrel_cluster installed in your system.

Have mongrel create a config file for you:

mongrel_rails cluster::configure -e production -p 5000 -a 127.0.0.1 -N 2 -c ~/grader/web
mkdir ~/grader/web/tmp/pids

The config file is located at ~/grader/web/config/mongrel_cluster.yml. It should look like this:

--- 
cwd: /home/ioi/grader/web
log_file: log/mongrel.log
port: "5000"
environment: production
address: 127.0.0.1
pid_file: tmp/pids/mongrel.pid
servers: 2

Next, start the server.

cd ~/grader/web
mongrel_rails cluster::start

See if it works by checking out http://localhost:5000/.

Connect mongrel_cluster with apache2

First, we edit apache2's configuration.

cd /etc/apache2/sites-available
sudo emacs default

Paste the following snippet of code into the bottom part of the file before </VirtualHost>

Alias /grader "/home/ioi/grader/web/public"
 
<directory "/home/ioi/grader/web/public/">
  Options FollowSymLinks
  AllowOverride None
  Order allow,deny
  Allow from all
</directory>
 
<proxy balancer://mongrel_cluster>
  BalancerMember http://127.0.0.1:5000
  BalancerMember http://127.0.0.1:5001
  Allow from all
</proxy>
 
<Location /balancer-manager>
  SetHandler balancer-manager
</Location>
 
RewriteEngine On
 
# Uncomment for rewrite debugging
# RewriteLog "/var/log/apache2/ioi_rewrite.log"
# RewriteLogLevel 9
 
# Redirect all non-static requests to cluster
RewriteCond %{REQUEST_URI} ^/grader/(.*)$
RewriteCond /home/ioi/grader/web/public/%{REQUEST_FILENAME} !-f
RewriteRule ^/grader/(.*)$ balancer://mongrel_cluster/grader/$1 [P,QSA,L]

Next, restart apache2.

/etc/init.d/apache2 restart

Edit routes.rb

cd ~/grader/web/config
emacs routes.rb

Add the bolden text to the file:

ActionController::Routing::Routes.draw do |map|
  # The priority is based upon order of creation: first created -> highest priority.
  
  # Sample of regular route:
  # map.connect 'products/:id', :controller => 'catalog', :action => 'view'
  # Keep in mind you can assign values other than :controller and :action

  # Sample of named route:
  # map.purchase 'products/:id/purchase', :controller => 'catalog', :action => 'purchase'
  # This route can be invoked with purchase_url(:id => product.id)

  # You can have the root of your site routed by hooking up  
  # -- just remember to delete public/index.html.
  map.connect 'grader/', :controller => 'main', :action => 'login'

  # Allow downloading Web Service WSDL as a file with an extension
  # instead of a file named 'wsdl'
  map.connect ':controller/service.wsdl', :action => 'wsdl'

  # Install the default route as the lowest priority.
  map.connect 'grader/:controller/:action/:id.:format'
  map.connect 'grader/:controller/:action/:id'
end

Edit environments/production.rb

cd ~/grader/web/config/environments
emacs production.rb

Set config.action_controller.asset_host to the URL of your grader site.

# Settings specified here will take precedence over those in config/environment.rb

# The production environment is meant for finished, "live" apps.
# Code is not reloaded between requests
config.cache_classes = true

# Use a different logger for distributed setups
# config.logger = SyslogLogger.new

# Full error reports are disabled and caching is turned on
config.action_controller.consider_all_requests_local = false
config.action_controller.perform_caching             = true

# Enable serving of images, stylesheets, and javascripts from an asset server
config.action_controller.asset_host                  = "http://<your-host-name-or-ip-address>/grader"

# Disable delivery errors, bad email addresses will be ignored
# config.action_mailer.raise_delivery_errors = false

Make a Symbolic Link Hack

In order to make CCS work, we need to create a symbolic link ~/grader/web/public/grader to ~/grader/web/public.

cd ~/grader/web/public
ln -s ~/grader/web/public grader

Restart mongrel_cluster

cd ~grader/web
mongrel_rails cluster::restart

And this should do it!