How To Install Ruby on Rails with rbenv on Debian 7 (Wheezy)

Introduction

Ruby on Rails is an open source web framework based on Ruby. It has been a popular choice among startups since it’s easier to build and ship the application. To start using Ruby on Rails, you need to have Ruby installed. However, due to the way Debian packaging system works, you’ll mostly end up with an old version of Ruby. So, this guide will show you a safe way for you to use the latest version of Ruby and Ruby on Rails.

Install rbenv

We need to install some packages so that Debian won’t complain about missing files or libraries. We’ll use Debian packaging system for that.

First we need to sure we have all the latest packages that can be installed:

sudo apt-get update

Next, we’ll install git package so that we can use git commands:

sudo apt-get install git-core

rbenv doesn’t provide any installer, so we have to get use the source from Github. So, we need to clone it in our home directory.

git clone https://github.com/sstephenson/rbenv.git ~/.rbenv

PATH is a variable used by Debian to search for executables whenever you run a command. So, we have to append path to rbenv executables in it. We have to do this every time we login as our user. So, we’ll use bashrc that will be run every time we login as a user:

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

Add another command in our bashrc for shims[1] and auto completion for rbenv:

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

Restart your shell (opening a new terminal tab should suffice). To check if everything is working, run:

type rbenv

You should get an output like this:

rbenv is a function

That’s it. You’ve just successfully installed rbenv. But we’re not done yet. To simplify ruby installation, we need to install ruby-build which is one of the rbenv plugins, by cloning it from Github:

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

Due to the way shims work, we need to run rbenv rehash every time we install or uninstall gem. To prevent it, we can use another rbenv plugin which will automatically do it for us. As usual, we’ll clone it for installation

git clone https://github.com/sstephenson/rbenv-gem-rehash.git ~/.rbenv/plugins/rbenv-gem-rehash

Install ruby

Alright, everything is done for our rbenv installation. Next, we will install a ruby. But before that, we need to install some required packages to ensure smooth installation.

apt-get install build-essential libssl-dev libcurl4-openssl-dev libreadline-dev -y

In order to list all available Ruby versions for you to choose, we can use:

rbenv install --list

I’ll just use version 2.1.0 for this guide. To install it, just run this command:

rbenv install 2.1.0 -k

-k will keep Ruby’s source. It will help building other gems in the future.

Right now, we need to set which version we want to use every time we run ruby command. Make sure you will remove any directory in your ~/.rbenv/sources if you encounter any problems for this command.

To set it for global usage, just run:

rbenv global 2.1.0

That’s it, now you have ruby 2.1.0 installed. You can verify it by running:

ruby -v

You should get something like this (depends on your version):

ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-linux]

Ruby on Rails Installation

Ruby on Rails (RoR) provides a command for your initial application creation. The command will setup your directories, gem dependencies and so on. Before running it, we need to ensure every required packages are installed.

By default, RoR will use sqlite as its database. In order to use it without any error, we need sqlite packages for Debian:

sudo apt-get install sqlite3 libsqlite3-dev

RoR will also requires JavaScript runtime[2]. There are multiple ways to do this, but we’ll use nodejs from Debian Backports[3] to install it.

To use it, we need to add Debian Backports repositories:

Open the file where your Debian repositories are defined:

sudo nano /etc/apt/sources.list

Append these lines into the file:

deb http://ftp.us.debian.org/debian/ wheezy-backports main
deb-src http://ftp.us.debian.org/debian/ wheezy-backports main

As usual, run this command to make sure you’ll get all of the packages list:

sudo apt-get update

To install nodejs, just run this command:

sudo apt-get -t wheezy-backports install nodejs

Go ahead and install Ruby on Rails with this command:

gem install rails

Out First Ruby on Rails Application

We’re now ready to create our first RoR application. Run this command to create it (you can change mynewapplication to anything you want):

rails new mynewapplication

It will automatically install required gems. After it’s finished, go into its directory:

cd mynewapplication

Run this command to start your application

rails s

Fire up your browser and go to this address:

http://your_ip_or_domain:3000

You should be seeing a Welcome aboard page. Click “About your application’s environment” and you should see something like below.

Congratulations! You’ve successfully installed and created your first RoR application.

[1]

https://assets.digitalocean.com/articles/Debian_Ruby_rbenv/WelcomeAboard.jpg

[2]

https://github.com/sstephenson/execjs#readme

[3]

http://backports.debian.org/