[chef] More Proposed Chef 12.0 Changes

[Daniel DeLeo < >]

Hi Chefs,  

I’ve proposed 2 more Changes for Chef 12.0. They are pretty small and 
hopefully not too controversial.

Firstly, I’d like to make chef-solo raise an error when attempting to 
`include_recipe` a recipe that’s not in the run_list or dependencies. The 
tl;dr here is that non-recipe files aren’t loaded if a cookbook isn’t in the 
run_list or dependency tree, which causes confusing errors. We would have 
like to have made this condition an error already, but decided not to in 
order to avoid any possibility of breakage. See these tickets for more 
background:

https://tickets.opscode.com/browse/CHEF-4367
https://tickets.opscode.com/browse/CHEF-5120

The chef-rfc issue for this change is here: 
https://github.com/opscode/chef-rfc/issues/42 ;(since it’s a small change it 
doesn’t get its own RFC, it would be added to RFC 015 
https://github.com/opscode/chef-rfc/blob/master/rfc015-chef-12.md

The second change I’m proposing is to finally remove the cookbook overlay 
feature. This is the feature (or mis-feature IMO) where, when a cookbook 
appears multiple times in your cookbook_path, chef combines it into a single 
cookbook with files overlaid. This feature has been deprecated since at least 
Chef 0.10.4 (deprecation warning was added to master in May 2011). There is 
more background in this ticket: https://tickets.opscode.com/browse/CHEF-2308

The chef-rfc issue for this change is here: 
https://github.com/opscode/chef-rfc/issues/43  ;

--  
Daniel DeLeo