create a method for documenting defaults and which pillar keys are available in the repo

[ketzacoatl]

Imagine a snippet like this:

 # install python and setuptools, leave pip to python.pip and dev to python.dev
{%- set default_2or3 = '' %}
{%- set _2or3 = salt['pillar.get']('python_2or3', default_2or3) %}

It would be really nice to have a tool that does the following:

• search for these set lines
• for all entries with default_ as the prefix, collect those as "defaults"
• for all entries with pillar.get, collect the keys, and the referenced defaults
• render a markdown file (or set of files) to document this aspect of the formula

[neilmayhew]

There's a Haskell library called ginger that could be used to parse the files. It would be possible to get the variable assignments from the parsed syntax tree, and then to find the ones we're interested in.

[neilmayhew]

PoC implementation in https://gitlab.fpcomplete.com/neil/salt-indexer. See especially README and NEWS.