cookbook_file resource in Chef

cookbook_file differs from something like a template is in that cookbook_file is for purely static content. There is no room for variables or dynamic content.
It transfers files from a sub-directory of a cookbook to the node.
Cookbook files are shipped with cookbook itself. These are cookbook files like configuration files, PHP files, things that are unlikely to change.

Example:
Generate a cookbook_file using the command:

chef generate file {{ cookbook }} {{ file_name }}

like below:

chef generate file apache index.html

Use cookbook_file resource:

package 'apache2' 
cookbook_file '/var/www/html/index.html' do 
  source 'index.html' 
end 
service 'apache2' do 
  action [:enable, :start ] 
end

Fill in cookbook_file index.html in the cookbook:

$ cat apache/files/default/index.html 
Hello world!

Converge the cookbook apache:

sudo chef-client -zr 'recipe[apache]'

Test the cookbook:

$ curl localhost
Hello world!