Ruby on Rails Linux Installations

We are installing Ruby On Rails on Linux using rbenv. It is a lightweight Ruby Version Management Tool. The rbenv provides an easy installation procedure to manage various versions of Ruby, and a solid environment for developing Ruby on Rails applications.

Follow the steps given below to install Ruby on Rails using rbenv tool.

Install Prerequisite Dependencies

 tp> sudo yum install -y git-core zlib zlib-devel gcc-c++ patch readline readline-devel libyaml-devel libffi-devel openssl-devel make bzip2 autoconf automake libtool bison curl sqlite-devel

Install rbenv

Now we will install rbenv and set the appropriate environment variables. Use the following set of commands to get rbenv for git repository.

tp> git clone git://github.com/sstephenson/rbenv.git .rbenv

tp> echo 'export PATH = "$HOME/.rbenv/bin:$PATH"' >> ~/.bash_profile

tp> echo 'eval "$(rbenv init -)"' >> ~/.bash_profile

tp> exec $SHELL

tp> git clone git://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build

tp> echo 'export PATH = "$HOME/.rbenv/plugins/ruby-build/bin:$PATH"' << ~/.bash_profile

tp> exec $SHELL

Install Ruby

Before installing Ruby, determine which version of Ruby you want to install. We will install Ruby 2.2.3. Use the following command for installing Ruby.

tp> rbenv install -v 2.2.3

Use the following command for setting up the current Ruby version as default.

tp> rbenv global 2.2.3

Use the following command to verify the Ruby version.

tp> ruby -v

Output

ruby 2.2.3p173 (2015-08-18 revivion 51636) [X86_64-linux]

Ruby provides a keyword gem for installing the supported dependencies; we call them gems. If you don't want to install the documentation for Ruby-gems, then use the following command.

tp> echo "gem: --no-document" > ~/.gemrc

Thereafter, it is better to install the Bundler gem, because it helps to manage your application dependencies. Use the following command to install bundler gem.

tp> gem install bundler

Install Rails

Use the following command for installing Rails version 4.2.4.

tp> install rails -v 4.2.4

Use the following command to make Rails executable available.

tp> rbenv rehash

Use the following command for checking the rails version.

tp> rails -v

Output

tp> Rails 4.2.4

Ruby on Rails framework requires JavaScript Runtime Environment (Node.js) to manage the features of Rails. Next, we will see how we can use Node.js to manage Asset Pipeline which is a Rails feature.

Install JavaScript Runtime

Let us install Node.js from the Yum repository. We will take Node.js from EPEL yum repository. Use the following command to add the EPEL package to the yum repository.
tp> sudo yum -y install epel-release

Use the following command for installing the Node.js package.

tp> sudo yum install nodejs

Create new default application with the following command

tp> rails new demo

Now Install dependency file using the following bundle command.

tp> bundle install

Now start the server using the following rails command

tp> ralis s     (or)  rails server

Now we will aim for setting up the oracle database

Open the database.yml file, and update the following database connection details Path for database.yml file is  config/database.yml

    development:

    adapter: oracle_enhanced

    database: databasename

    host:  Ipaddress/databasename

    username: xxxxxx

    password: xxxxxx

Add the following 2 lines in the gemfile under the following path.

/<projectname>/Gemfile

gem 'activerecord-oracle_enhanced-adapter'

gem 'ruby-oci8'

Now connecting to the oracle database we should have following tool gem installation

     tp> gem install activerecord-oracle_enhanced-adapter

        tp> gem install ruby-oci8

But ruby-oci8 fail due to lack of libraries. We need have oracle instant client to include the libraries.

Follow the below process to install ruby-oci8

http://www.oracle.com/technetwork/topics/linuxx86-64soft-092277.html

Install: -     Instant Client Package – Basic

                   Instant Client Package – SDK

Unzip those zip files under your home directory

tp> unzip zip file name Instant Client Package – Basic

tp> unzip zip file name Instant Client Package – SDK

Copy the sdk folder from Instant Client Package – SDK and copy to Instant Client Package – Basic to include missing oci.h file

Now we must include the path

tp> vi .bashrc

export LD_LIBRARY_PATH=/home/liginauthor/instantclient_12_1

export PATH=$PATH:$LD_LIBRARY_PATH

export PATH

tp> vi bashprofile

PATH=$PATH:$HOME

export PATH

eval "$(rbenv init -)"

To make this change more permanent edit your config/boot.rb and add this:

require 'rails/commands/server'

module Rails

  class Server

    def default_options

      super.merge(Host:  '0.0.0.0', Port: 3000)

    end

  end

end

Note:- While installing ruby oci8 we may get an error for creating a creating a soft link  just follow the instructions to fix the problem

Now set the etc host

Add your host name to its Ip address

tp> vi /etc/hosts

Run rails s

Stop scaffold-->  spring stop