[chef] dynamically setting attributes

[Jenn Fountain < >]

Ohai!

I am trying to create a generic cookbook that will deploy different 
applications.  Everything about these app installations are the same save the 
installation URL.  What I want to do may not even be possible or I should do 
it another way.  I am hoping someone here could give me some suggestions.

Each of these applications has a testing, staging and production environment. 
 As a result, three different installation URLs.

Each application name is set using this attribute in the role:
default[:application][:name] = nil

And I want to set the install URL in the environment and reference it like 
this or however I need to reference it (this is where I am not sure :D):

default#{node[:application][:name]}[:install][:url] = nil

For example:

default[:application][:name] = ‘myapp’ in the “myapp” role

default[:myapp][:install][:url] = http://someurl/myapp.git  ;<<— where :myapp 
is pulled from the above attribute.

I thought about databags, creating different Roles - "Myapp - Testing role” 
but I really was hoping to pull it from the name.

Any ideas would be appreciated.  Can I even do this? Should I? :D 

Thanks!!!

-J