$ rvm get stable
$ rvm list known
$ rvm upgrade 2.0.0p353 2.1.0
$ rvm get stable
$ rvm get stable
$ rvm list known
$ rvm upgrade 2.0.0p353 2.1.0
I just realized I’m running an out-of-date version of Ruby (1.9.3-p327), and browsed to the Ruby website to find out what the latest, stable version is. It turns out 1.9.3-p362 is the latest version:
Well, that doesn’t seem right. Lets list the versions of Ruby that RVM knows about:
$ rvm list known # MRI Rubies [ruby-]1.8.6[-p420] [ruby-]1.8.7[-p371] [ruby-]1.9.1[-p431] [ruby-]1.9.2[-p320] [ruby-]1.9.3-p125 [ruby-]1.9.3-p194 [ruby-]1.9.3-p286 [ruby-]1.9.3-[p327] [ruby-]1.9.3-head [ruby-]2.0.0-preview2 ruby-head
Now that’s more like it. Lets see what “rvm list known” shows us now:
$ rvm list known # MRI Rubies [ruby-]1.8.6[-p420] [ruby-]1.8.7[-p371] [ruby-]1.9.1[-p431] [ruby-]1.9.2[-p320] [ruby-]1.9.3-p125 [ruby-]1.9.3-p194 [ruby-]1.9.3-p286 [ruby-]1.9.3-p327 [ruby-]1.9.3[-p362] [ruby-]1.9.3-head [ruby-]2.0.0-preview2 ruby-head
Annnd there’s the 1.9.3-p362 version, ready for installation with the usual “rvm install ruby-1.9.3-p362” command.
RVM, or Ruby Version Manager is a popular and effective way to manage running multiple Ruby environments. Here is how you set it up on CentOS 5.5:
1) Add the Webtatic respository and install Git.
rpm -Uvh http://repo.webtatic.com/yum/centos/5/latest.rpm yum install --enablerepo=webtatic git
(Note that this command will also install the perl-Error and perl-Git dependencies)
2) Create an rvm user and group.
groupadd rvm useradd -g rvm rvm
3) Add the root user to the rvm group (required for installation)
usermod -a -G rvm root
4) Install RVM as root.
bash < <(curl -L http://bit.ly/rvm-install-system-wide) % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 5840 100 5840 0 0 1620 0 0:00:03 0:00:03 --:--:-- 5653 Group 'rvm' exists, proceeding with installation. Adding 'root' to the group 'rvm' Creating the destination dir and making sure the permissions are correct Cloning into rvm... remote: Counting objects: 4206, done. remote: Compressing objects: 100% (2029/2029), done. Receiving objects: 26% (1094/4206), 796.00 KiB | 54 KiB/s .... Setting up group permissions Generating system wide rvmrc Generating /usr/local/lib/rvm to load rvm Correct permissions on rvmrc and the rvm loader RVM is now installed. To use, source '/usr/local/lib/rvm' to your shell profile.
5) Install zlib via RVM.
# rvm package install zlib Fetching zlib-1.2.5.tar.gz to /usr/local/rvm/archives % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 531k 100 531k 0 0 206k 0 0:00:02 0:00:02 --:--:-- 226k Extracting zlib-1.2.5.tar.gz to /usr/local/rvm/src Configuring zlib in /usr/local/rvm/src/zlib-1.2.5. Compiling zlib in /usr/local/rvm/src/zlib-1.2.5. Installing zlib to /usr/local/rvm/usr
6) Install Ruby 1.9.2 using RVM.
# rvm install 1.9.2 -C --with-zlib-dir=/usr/local/rvm/src/ Installing Ruby from source to: /usr/local/rvm/rubi while depending on your cpu(s)... ruby-1.9.2-p180 - #fetching ruby-1.9.2-p180 - #extracting ruby-1.9.2-p180 to /u ruby-1.9.2-p180 - #extracted to /usr/local/rvm/src/ ruby-1.9.2-p180 - #configuring ruby-1.9.2-p180 - #compiling ruby-1.9.2-p180 - #installing ruby-1.9.2-p180 - Updating #rubygems to the latest. Removing old Rubygems files... Installing rubygems dedicated to ruby-1.9.2-p180... Installing rubygems for /usr/local/rvm/rubies/ruby-1.9.2-p180/bin/ruby Installation of rubygems completed successfully. ruby-1.9.2-p180 - Updating #rubygems to the latest. Removing old Rubygems files... Installing rubygems dedicated to ruby-1.9.2-p180... Installing rubygems for /usr/local/rvm/rubies/ruby-1.9.2-p180/bin/ruby Installation of rubygems completed successfully. ruby-1.9.2-p180 - adjusting #shebangs for (gem irb erb ri rdoc testrb rake). ruby-1.9.2-p180 - #importing default gemsets (/usr/local/rvm/gemsets/) Install of ruby-1.9.2-p180 - #complete
7) Set the RVM default to version 1.9.2
# rvm --default use 1.9.2 Using /usr/local/rvm/gems/ruby-1.9.2-p180
8) Verify that Ruby version 1.9.2 was installed successfully.
# ruby -v ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
9) Add this environment variable to root’s .bash_profile file.
[[ -s "/usr/local/rvm/scripts/rvm" ]] && . "/usr/local/rvm/scripts/rvm"
10) Install rails.
# gem install rails Fetching: activesupport-3.0.5.gem (100%) Fetching: builder-2.1.2.gem (100%) Fetching: i18n-0.5.0.gem (100%) ... Installing RDoc documentation for railties-3.0.5... Installing RDoc documentation for bundler-1.0.10... Installing RDoc documentation for rails-3.0.5...< /pre>
UPDATE 7/25/2011: The system-wide install script is no longer available on github, and has been removed by the author. A workaround link is posted in the comments on this Stack Overflow discussion.
Need to run Rails apps under Apache? Phusion’s Passenger is becoming the de-facto standard for doing so with its ease of setup, low memory footprint, and deep support. Once you have Ruby and Rails setup on your CentOS server (see this post), you can install Passenger and integrate it with Apache. Here’s how:
1) Install the Apache development tools
Passenger is nothing more than a dynamic shared object (DSO). You will need the httpd-devel package to build Dynamic Shared Objects (DSOs) for Apache. The following command will install it:
yum install httpd-devel
Depending on your server, you will notice a number of dependent packages being installed, including apr-devel, perl, and apr-util-devel.
2) Install Passenger.
Passenger is a gem, and installed in the typical fashion of any gem:
gem install passenger Building native extensions. This could take a while... Building native extensions. This could take a while... Successfully installed fastthread-1.0.7 Successfully installed passenger-2.2.15 2 gems installed Installing ri documentation for fastthread-1.0.7... Installing ri documentation for passenger-2.2.15... Installing RDoc documentation for fastthread-1.0.7... Installing RDoc documentation for passenger-2.2.15...
3) Build Passenger for Apache
Passenger has a scripted installer. Start it with this command:
Follow the onscreen keyboard prompts from the script, and you will see build messages scroll quickly by as the binaries are built. If the build is successful, you will be presented with this final screen before the shell script exits:
4) Integrate Passenger with Apache
Before beginning, make a copy of your Apache httpd.conf file:
cp /etc/httpd/conf/httpd.conf httpd.conf.orig
Now scroll down to the end of the file, and add these lines to help the Passenger shared object find the ruby and gem binaries:
PassengerRoot /usr/local/lib/ruby/gems/1.9.1/gems/passenger-2.2.15 PassengerRuby /usr/local/bin/ruby
5) Add a symlink to your app
Change to the directory specified by the server-wide DocumentRoot directive (/var/www/html) and add a symlink to your Rails application. In this case, our Rails application lives in the /webapps/todos directory, so the symlink should link to the “public” directory of the application:
ln -s /webapps/todos/public/ todos
6) Add a virtual host directive for your Rails application
Point Apache to your Rails application:
ServerName localhost DocumentRoot /var/www/html RailsEnv development Allow from all Options -MultiViewsRailsBaseURI /todos
Now restart Apache with an “apachectl restart” command, and browse to your Rails app. That’s it!
Red Hat Linux (and its recompiled cousin, CentOS) has a fantastic reputation for stability and maturity. However, this often means that packages included with the OS are somewhat out-of-date by the time the distribution is released. For example, the latest version of CentOS is 5.5, and the version of Ruby that ships with it is version 1.8.5, which dates back to August 2006. Even the Ruby group recommends using nothing less than 1.8.7 for Rails development.
So how do you get the stability of Red Hat with the goodness of Ruby? Compile from source to get the latest, greatest version. Here’s how:
1) Install CentOS 5.5
To save yourself alot of headaches during the installation, check to see if you have the “Development Tools” group installed with this command:
# yum grouplist |grep -i Development
If you don’t have it, install the package group with this command:
#yum groupinstall "Development Tools"
Note that you may also have the older version of Ruby installed via RPM’s. You can check to see if you have it with this command:
# rpm -qa |grep ruby
If you discover an older version, uninstall it before proceeding (rpm -e <package_name>).
2) Create a /sources directory and change to that directory.
3) Download and build Ruby.
Download the latest Ruby source code (latest version is 1.9.2-p0 as of this writing).
Uncompress the tarball and build Ruby:
tar -zxvf ruby-1.9.2-p0.tar.gz cd ruby-1.9.2-p0 ./configure make make install
If you have all the proper dependencies, you should have no errors during the configure or make phases. This will install Ruby to the following directories:
/usr/local/include/ruby /usr/local/bin/ruby /usr/local/lib/ruby /usr/local/share/doc/ruby/html /usr/local/share/man1
Once the install is complete, verify the version of Ruby:
# ruby -v ruby 1.9.2p0 (2010-08-18 revision 29036)
The Ruby source package also installs RubyGems, the Ruby package manager. Verify the version of RubyGems:
# gem -v 1.3.7
4) Check for updated gems
Ensure you have the latest gem versions by running this command:
# gem update --system
5) Install the rake build language
# gem install rake
6) Install rails
# gem install rails
7) List the installed gems.
# gem list
That’s it! You now have a fully-installed Ruby on Rails stack. However, Ruby also needs a back-end database and a web server for its presentation layer. Future posts will detail how to install and integrate web server and database tiers with Rails.