install

howto
Step One— Install Ruby with RVM
Before we do anything else, we should run a quick update to make sure that all of the packages we download to our VPS are up to date:

sudo apt-get update
Once that’s done, we can start installing RVM, Ruby Version Manager. This is a great program that lets you use several versions of Ruby on one server; however, in this case, we will just use it to install the latest version of Ruby on the droplet.

If you do not have curl on your system, you can start by installing it:

sudo apt-get install curl
To install RVM, open terminal and type in this command:

\curl -L https://get.rvm.io | bash -s stable
After it is done installing, load RVM. You may first need to exit out of your shell session and start up a new one.

source ~/.rvm/scripts/rvm
In order to work, RVM has some of its own dependancies that need to be installed. To automatically install them:

rvm requirements
You may need to enter your root password to allow the installation of these dependencies.

On occasion the zlib package may be reported as missing. The RVM page describes the issue and the solution in greater detail here.
In some rare cases it might be required to install packages via rvm pkg, if unsure try installing ruby first.

RVM can install required packages automatically via autolibs:

rvm autolibs rvm_pkg
This will tell RVM to install the missing dependencies, RVM will try to detect what is missing using pkg-config, as not all packages provide it please do not be surprised RVM will insist on installing readline - even it was installed.

Step Two—Install Ruby
Once you are using RVM, installing Ruby is easy.

rvm install ruby
The latest ruby is now installed. However, since we accessed it through a program that has a variety of Ruby versions, we need to tell the system to use the version we just installed by default.

rvm use ruby –default
Step Three—Install RubyGems
The next step makes sure that we have all the required components of Ruby on Rails. We can continue to use RVM to install gems; type this line into terminal.

rvm rubygems current
Step Four—Install Rails
Once everything is set up, it is time to install Rails. To start, open terminal and type in:

gem install rails
This process may take a while, be patient with it. Once it finishes you will have Ruby on Rails installed on your droplet.

See More
Once you have installed Ruby on Rails on your server, you can proceed to Create a SSL Certificate for your site or Install an FTP server