How can I put the output of a Chef 'execute resource' into a variable

Question

I'd like to put the output of a shell command into a variable for later use in a Chef recipe.

In bash I could do something like output=`tail -1 file.txt` and then I could echo $output

Can an 'execute resource' do this so that I can use the result later in the recipe?

Answer 1

while Graham's solution seemed to work at first, I found out about Chef::Mixin:ShellOut

ruby_block "check_curl_command_output" do     block do       #tricky way to load this Chef::Mixin::ShellOut utilities       Chef::Resource::RubyBlock.send(:include, Chef::Mixin::ShellOut)             curl_command = 'curl --write-out %{http_code} --silent --output /dev/null '+node['url']       curl_command_out = shell_out(curl_command)       if curl_command_out.stdout == "302"         ...       else         ...       end     end     action :create end 

Chef::Mixin:ShellOut is particularly useful if you need to run the command as a specific user (cf. http://www.slideshare.net/opscode/chef-conf-windowsdougireton ):

ruby_block "run_command_as" do     block do     Chef::Resource::RubyBlock.send(:include,Chef::Mixin::ShellOut)     add_group = shell_out("your command",         {           :user => "my_user",           :password => "my_password",           :domain => "mycorp.com"         }         )     end end 

Answer 2

Works for me

passenger_root = shell_out("passenger-config --root").stdout