Install Redmine on Ubuntu server

First Install the following packages.

sudo apt-get install build-essential ruby ruby1.8-dev libopenssl-ruby libmysql-ruby rubygems rake

Install rails.

sudo gem install rails -v=2.3.5

Then create symbolic link to rails.

sudo ln -s /var/lib/gems/1.8/bin/rails /usr/bin/rails

Go to www directory and checkout redmine from SVN.

cd /var/www
svn checkout http://redmine.rubyforge.org/svn/trunk redmine

Copy config file.

sudo cp redmine/config/database.yml.example redmine/config/database.yml

Change database configuration.

sudo nano redmine/config/database.yml
production:
adapter: mysql
database: redmine
host: localhost
username: redmine
password: redmine's password
encoding: utf8

Optional to change email configuration.

sudo cp redmine/config/email.yml.example redmine/config/email.yml
sudo nano redmine/config/email.yml
production:
delivery_method: :sendmail

Then go to redmine directory and generate a session store secret.

cd redmine
RAILS_ENV=production rake config/initializers/session_store.rb

Create database structure.

RAILS_ENV=production rake db:migrate

Add default configuration data to database.

RAILS_ENV=production rake redmine:load_default_data

Now run Redmine for firs time temporally.

ruby script/server webrick -e production

Now we can access Redmine at http://localhost:3000
Use following commands to running redmine on apache and Enable mod proxy and rewrite.

sudo a2enmod proxy
sudo a2enmod rewrite

Restart apache and install mongrel.

sudo /etc/init.d/apache2 restart
sudo apt-get install mongrel

Create folder mongrel inside /var/log.

sudo mkdir /var/log/mongrel

When you are in redmine directory Start mongrel.

sudo mongrel_rails start -d -p 3000 -e production -P /var/log/mongrel/mongrel-1.pid -l /var/log/mongrel/mongrel.log

Access redmine at http://localhost:3000
Create apache’s virtual host.

sudo nano /etc/apache2/sites-available/redmine

Add following proxy configuration.

<virtualhost *:80>
ServerName http://localhost
ProxyPass / http://localhost:3000/
ProxyPassReverse / http://localhost:3000
ProxyPreserveHost on
<proxy *>
Order allow,deny
Allow from all
</Proxy>
</VirtualHost>

Create symbolic link.

sudo ln -s /etc/apache2/sites-available/redmine /etc/apache2/sites-enabled/redmine

Restart apache.

sudo /etc/init.d/apache2 restart

Access redmine at http://localhost:3000
If you need to stop mongrel, run the following command inside redmine directory.

sudo mongrel_rails mongrel::stop -P /var/log/mongrel/mongrel-1.pid

Possible errors and solutions
To see the running rubby sessions

lsof|grep 3000

This will give you a line starting with.

ruby 6205 admin 4u IPv4

If you need destroy the session

kill -9 6205

If you see followwing error

** !!! PID file /var/log/mongrel/mongrel-1.pid already exists. Mongrel could be running already. Check your /var/log/mongrel/mongrel.log for errors.
** !!! Exiting with error. You must stop mongrel and clear the .pid before I'll attempt a start.

Use following command or destroy session using above step.

rm /var/log/mongrel/mongrel-1.pid
rm /var/log/mongrel/mongrel.log

Thank goes to Just Notes