gem install knife-ec2 error - amazon-ec2

Question

I have installed a chef-server on a centos machine and I have also set up a workstation on another centos machine.
I have also set up the knife. Now I want to install knife-ec2 plug-in.
I am trying to install the knife plugin but getting the following error :
[root#ip-server-ip- chef-repo]# /opt/chef/embedded/bin/gem install knife-ec2
Building native extensions. This could take a while...
Building nokogiri using packaged libraries.
ERROR: Error installing knife-ec2:
ERROR: Failed to build gem native extension.
/opt/chef/embedded/bin/ruby extconf.rb
Building nokogiri using packaged libraries.
checking for iconv.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.
Provided configuration options:
--with-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/opt/chef/embedded/bin/ruby
--help
--clean
--use-system-libraries
--enable-static
--disable-static
--with-zlib-dir
--without-zlib-dir
--with-zlib-include
--without-zlib-include=${zlib-dir}/include
--with-zlib-lib
--without-zlib-lib=${zlib-dir}/lib
--enable-cross-build
--disable-cross-build
/opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:506:in `try_cpp'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:931:in `block in have_header'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:280:in `postpone'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for'
from /opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:930:in `have_header'
from extconf.rb:103:in `have_iconv?'
from extconf.rb:148:in `block (2 levels) in iconv_prefix'
from extconf.rb:90:in `preserving_globals'
from extconf.rb:143:in `block in iconv_prefix'
from extconf.rb:116:in `block in each_iconv_idir'
from extconf.rb:113:in `each'
from extconf.rb:113:in `each_iconv_idir'
from extconf.rb:137:in `iconv_prefix'
from extconf.rb:424:in `block in <main>'
from extconf.rb:161:in `block in process_recipe'
from extconf.rb:154:in `tap'
from extconf.rb:154:in `process_recipe'
from extconf.rb:419:in `<main>'
Gem files will remain installed in /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.2.1 for inspection.
Results logged to /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.2.1/ext/nokogiri/gem_make.out
How to resolve this error.
Any lead is highly appreciated.
Thanks

Answer 1

The knife-ec2 gem dependes on a gem called nokogiri. The nokogiri gem is a binary and needs to be compiled when it is installed. If you scroll down the error message you will see the following line:
/opt/chef/embedded/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
It's just telling you to install gcc and make on your workstation. In centos you can do this by running:
$ sudo yum groupinstall development-tools
This will get you everything you need to start compiling gem binaries.
If you are just starting out with chef I would actually recommend the chef development kit, Chef-DK. It gives you all the tools you need to get started along with testing tools and helper commands to generate cookbooks.
Good Luck!

Answer 2

Try installing the following packages . I faced a similar error while installing . My problem solved . It might help you .
sudo apt-get install build-essential
sudo apt-get install g++ build-essential
sudo apt-get install rubygems ruby1.9.1
And then install knife ec-2 pluggin
$ /opt/chef/embedded/bin/gem install knife-ec2