RFC | Title | Author | Status | Type |
---|---|---|---|---|
40 |
On-Demand Cookbook Libraries |
John Keiser <[email protected]> |
Accepted |
Standards Track |
As a library cookbook writer,
I want to have nested directories,
So that I can organize my code and make it more readable.
As a library cookbook writer,
I want to control the load order of my library,
So that I can have code in one file that refers to code in another file without constraining the filenames.
As a library cookbook writer,
I want to be able to `require` files in my library cookbook,
So that I don't have to deal with the pitfalls of `require_relative` (particularly that it loads things multiple times).
As a library cookbook user,
I want to be able to `require` files in the library cookbooks I use,
So that I can pick and choose what functionality I want to load.
When a user creates a cookbook, they can add the following directive to the metadata:
# metadata.rb
name "mylibrary"
version "0.0.1"
eager_load_libraries false
If eager_load_libraries
is false, Chef Client would instead append it to the ruby load path. This would occur in the phase where the libraries
files of a cookbook otherwise be automatically required in alphabetical order. All recipes, libraries, and other Ruby code running in the Chef Client can then use require 'filename'`` and it will load
cookbooks/mycookbook/libraries/filename` if present.
If eager_load_libraries
contains a list of files or globs, the library path is appended to the Ruby load path, and the listed files are loaded during the library load phase.
If eager_load_libraries
is true
or not specified, Chef Client loads the top level of files in alphabetical order, as before.
When a user wants to create a more complex library cookbook with multiple Ruby files, they have an issue right now: the library is automatically loaded in alphabetical order, making it hard to organize files. You can circumvent it somewhat using require_relative
to load the other files out of order, but that may load a file twice, leading to other problems. This RFC circumvents that by requiring files to be loaded explicitly by the user or library writer using require
, but allowing for an entry point (default.rb
).
There is also the fact that you don't necessarily need all the functionality in a library cookbook, and this RFC lets you pick and choose what to load.
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