== Installation

Installing cafe-grader can be done in the following steps.

1. Set up database. We need MySQL 5 database name, username and password.
2. Install RVM. cafe-grader runs on Ruby on Rails and the best way to install it is to use RVM.
3. Install necessary package for the system
4. Install cafe-grader from github
5. Deploy cafe-grader on apache with Phusion Passenger

The detail of each step are provided as follows.

=== Install MySQL 5

Install MySQL server for the server.

    $ sudo apt install mysql-server

Next, we will connect to mysql as root and set up the database. You can choose your DATABASENAME, USERNAME and PASSWORD.

    sudo mysql -u root

    mysql> create database DATABASENAME;
    Query OK, 1 row affected (0.00 sec)

    mysql> grant all privileges on grader.* to USERNAME@localhost identified by 'PASSWORD';
    Query OK, 0 rows affected, 1 warning (0.00 sec)

    mysql> flush privileges;
    Query OK, 0 rows affected (0.00 sec)

=== Install RVM

Since Ubuntu has dedicated package for RVM we will use that. Just follow instruction given in https://github.com/rvm/ubuntu_rvm. For your convenience, the step are reproduced here.

First, we install necessary package for installing RVM.

    $ sudo apt install software-properties-common

Second, we add the custom PPA, update the system and install RVM.

    $ sudo apt-add-repository -y ppa:rael-gc/rvm
    $ sudo apt-get update
    $ sudo apt-get install rvm

This is very important. You have to logout and login again since RVM change a lots of system. 

=== Install necessary package

    $ sudo apt install libmysql-dev default-jdk unzip nodejs php7.2-cli apache2 dirmngr gnupg apache2-dev


curl build-essential


=== Install cafe-grader

First, ensure that RVM is installed correctly.

If instead of this you get the following error, it is very likely that you have not use bash --login.

Next, we will let the install script do the work of installing cafe-grader. Please prepare the DATABASENAME, USERNAME and PASSWORD as the script will ask for that. Make sure that you run the script from the home directory of the user.

    cafe@grader:~$ wget https://github.com/cafe-grader-team/cafe-grader-judge-scripts/raw/master/installer/install-ubuntu-18.04.sh
    cafe@grader:~$ . ./install-ubuntu-18.04.sh

After installation is finished, grader is ready to run in development mode via WEBrick. We will try that by the following command which will start a grader accessible via http://localhost:3000/. You should try logging in to the system and verify that it is actually work.

cafe@grader:~/cafe_grader/web$ rails s

We are almost done. The last step is to set up apache and Phusion so that cafe-grader is served by apache. 

=== Deploy cafe-grader on Phusion passenger via apache
Basically, we will follow the instructions given in https://www.phusionpassenger.com/library/walkthroughs/deploy/ruby/ownserver/apache/oss/bionic/install_passenger.html, which devided into two parts: Installing Passenger and deploying the app.

Installing Passenger as a mod for apache and enable it. 

cafe@grader:~$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 561F9B9CAC40B2F7
    cafe@grader:~$ sudo apt-get install -y apt-transport-https ca-certificates
    cafe@grader:~$ sudo sh -c 'echo deb https://oss-binaries.phusionpassenger.com/apt/passenger bionic main > /etc/apt/sources.list.d/passenger.list'
    cafe@grader:~$ sudo apt-get update
    cafe@grader:~$ sudo apt-get install -y libapache2-mod-passenger
    cafe@grader:~$ sudo a2enmod passenger


    cafe@grader:~$ sudo apache2ctl restart

    Finally, we should check that passenger is installed correctly. Run the following command and fix anything as suggested by the command.

    cafe@grader:~$ sudo /usr/bin/passenger-config validate-install



Deploying the app. First, we determine the exact location of our ruby that is installed via RVM. 

    cafe@grader:~$ passenger-config about ruby-command
passenger-config was invoked through the following Ruby interpreter:
  Command: /home/cafe/.rvm/gems/ruby-2.3.7/wrappers/ruby
  Version: ruby 2.3.7p456 (2018-03-28 revision 63024) [x86_64-linux]
  To use in Apache: PassengerRuby /home/cafe/.rvm/gems/ruby-2.3.7/wrappers/ruby
  To use in Nginx : passenger_ruby /home/cafe/.rvm/gems/ruby-2.3.7/wrappers/ruby
  To use with Standalone: /home/cafe/.rvm/gems/ruby-2.3.7/wrappers/ruby /usr/bin/passenger start

Then, take note of the path after "Command". For this guide, it is /home/cafe/.rvm/gems/ruby-2.3.7/wrappers/ruby 

Assuming that cafe-grader is installed at /home/cafe/cafe_grader, we will edit the site config file of the apache as follow.

    <VirtualHost *:80>
        #ServerName www.example.com

        ServerAdmin webmaster@localhost
        # dont forget to change the document root
        DocumentRoot /home/cafe/cafe_grader/web/public
    
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined

        # add Passenger
        PassengerRuby /home/cafe/.rvm/gems/ruby-2.3.7/wrappers/ruby

        # our cafe-grader app
        <Directory /home/cafe/cafe_grader/web/public>
                Allow from all
                Options -MultiViews
                Require all granted
        </Directory>
    </VirtualHost>


Be noted that we make 3 modifications: 1) change DocumentRoot, 2) add PassengerRuby option and add 3) Directory directive
As the last step, we restart apache again and the site is ready to be used.

    cafe@grader:~$ sudo apache2ctl restart