Chef

Omnibus installer
release notes; http://lists.opscode.com/sympa/arc/chef/2011-12/msg00225.html

curl -L http://www.opscode.com/chef/install.sh | bash

sudo /opt/opscode/setup.sh -v validation.pem -o limepepper

Site Specific Cookbooks
You can also make your own site specific copies of cookbooks. ~/.chef/knife.rb or ~/chef-repo/.chef/knife.rb cookbook_path     [ "chef-repo/cookbooks", "chef-repo/site-cookbooks" ]

could create a maintainence cookbook with per OS recipes;

case node.platform when :debian include_recipe("maintenance::debian") when :ubuntu include_recipe("mainentance::ubuntu") else # ...   end

Log a message

Chef::Log.info("No nodes returned from search, using this node so hosts.cfg has data")

Tutorials
http://blog.afistfulofservers.net/post/2011/03/16/a-brief-chef-tutorial-from-concentrate/

chef at rightscale

http://support.rightscale.com/12-Guides/Chef_Cookbooks_Developer_Guide/02-Getting_Started/06-Intermediate_2_Chef_Tutorial