Build your first application using native Ruby on RHEL 6 or RHEL 7

Tags: hello world, ruby, RHEL, application, Red Hat Software Collections, environment, develop
     

    Get started developing with Ruby on Red Hat Enterprise Linux in under 10 minutes.

    Introduction and Prerequisites

    In this tutorial, you will see how to get started with Ruby development on Red Hat Enterprise Linux by creating a simple Hello World application. The tutorial should take five to ten minutes to complete.

    Before you begin, you will need a current Red Hat Enterprise Linux 6 or 7 workstation or server subscription that allows you to download software and get updates from Red Hat. If you don’t have an active subscription, register and obtain the RHEL Developer Suite (includes RHEL server) from here.

    The native version of Ruby are:

    • Red Hat Enterprise Linux 6 - 1.8.7
    • Red Hat Enterprise Linux 7 - 2.0

    If you want a newer version of Ruby for either RHEL 6 or 7, use the updated versions available via Red Hat Software Collections.

    If you have problems at any point, see Troubleshooting and FAQ.

     

    1. Prepare your system

    2 minutes

    In this step, you will download and install the latest updates from Red Hat for your system. In the process, you will verify that your system has a current Red Hat subscription and is able to receive updates.

    First, start a Terminal window from the Application menu. Then after using su to change to the root user ID, use subscription-managerto verify that you have access to Red Hat Software Repositories.

    $ su -
    # subscription-manager repos --list-enabled

    If you don’t see any enabled repositories, your system might not be registered with Red Hat or might not have a valid subscription. See Troubleshooting and FAQ for more information.

    Now download and install any available updates by running yum update. If updates are available, yum will list them and ask if it is OK to proceed.

    # yum update

     

    2. Setup your development environment

    2 minutes

    In this step you will download and install Ruby with a single command. If you don’t already have a Terminal window open, start one from the Applications menu. You will need to use su to run with root privileges.

    $ su -
    # yum install ruby

    To see what other Ruby packages are included with Red Hat Enterprise Linux, run this command:

    # yum list available ruby\*

    You are now done with the part that requires root privileges. Type exit to return to your normal user ID.

    # exit
    $

    If you need help, see Troubleshooting and FAQ.

     

    3. Hello World and your first application

    2 minutes

    In this step, you will first run Ruby in interactive mode. Then you will create a Ruby application that can be run from the command line. If you don’t have a Terminal window open, start it from the Applications menu. You should run under your normal user ID, If you are still running as root, type exit.

    $ irb
    irb(main):001:0> puts "Hello, Red Hat Developer Program World from Ruby " + RUBY_VERSION
    Hello, Red Hat Developer Program World from Ruby
    => nil
    irb(main):002:0> quit

    The next step is to create a Ruby application that can be run from the command line. Using your preferred text editor, create a file named hello.rb:

    $ nano hello.rb

    Add the following text to the file:

    #!/usr/bin/env ruby
    #
    puts "Hello, Red Hat Developer Program World from Ruby " + RUBY_VERSION

    Save it and exit the editor. Then make the script executable and run it:

    $ chmod +x hello.rb
    $ ./hello.rb
    Hello, Red Hat Developer Program World from Ruby 2.0.0

    Where to go next?

    Learn Ruby in 20 Minutes at Ruby-lang.org
    https://www.ruby-lang.org/en/documentation/quickstart/

    Find additional Ruby packages
    $ yum list available ruby\*

    Want to know more about what you can do with RHEL?

    Become a Red Hat developer: developers.redhat.com

    Red Hat delivers the resources and ecosystem of experts to help you be more productive and build great solutions. Register for free at developers.redhat.com.

    Follow the Red Hat Developer Blog
    https://developers.redhat.com/blog/

    Learn about Red Hat Software Collections

    Red Hat Software Collections deliver the latest stable versions of dynamic languages, open source databases, and web development tools that can be deployed alongside those included in Red Hat Enterprise Linux. Red Hat Software Collections is available with select Red Hat Enterprise Linux subscriptions and has a three-year life cycle to allow rapid innovation without sacrificing stability.

    Troubleshooting and FAQ

    1. My system is unable to download updates from Red Hat?

      I don’t have a current Red Hat subscription, can I get an evaluation?

      If you don’t have a Red Hat Enterprise Linux subscription, you can try it for free. Get started with an evaluation at https://access.redhat.com/products/red-hat-enterprise-linux/evaluation. Developers should select the Red Hat Enterprise Linux Developer Workstation option to ensure your evaluation includes additional tools from the Red Hat Developer Toolset and Red Hat Software Collections.

    2. How can I get a newer version of Ruby on Red Hat Enterprise Linux?

      A newer version of Ruby is available through Red Hat Software Collections which delivers the latest stable versions of dynamic languages, open source databases, and web development tools that can be deployed alongside those included in Red Hat Enterprise Linux. Red Hat Software Collections is available with select Red Hat Enterprise Linux subscriptions and has a three-year life cycle to allow rapid innovation without sacrificing stability.

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