Extend postgresql_conf to support multiple config files using ParsedFile

[ekohl]

To avoid a custom postgresql_conf implementation, this reverts back to ParsedFile. It relies on puppetlabs/puppet#9130 since there were bugs in it, which is why it's now a draft.

[ekohl]

I kept key instead of name to force me to implement ParsedFile agnostic of the name parameter. At this point I think it could revert back to name.

[ekohl]

I didn't have time to figure out how title_patterns works with matching, but it probably isn't hard.

[bastelfreak]

that really depends on the point of view :D

[ekohl]

It comes down to understanding https://github.com/puppetlabs/puppet/blob/945beb6ef0200b1bc7879b62131282a61fc9a935/lib/puppet/resource.rb#L625-L663 and finding the right combination.

[ekohl]

Ok, couldn't help myself. I think the commented code should work. The reason it's commented is that I didn't know if it would really work. But this part suggests the patterns are correct:

require 'test/unit'

TITLE_PATTERNS = [ 
  [ /^(.+\.conf):([\w.]+)$/m, [ [:target], [:key] ] ],
  [ /^([\w.]+)$/m, [ [:key] ] ],
]

def match(title)
  h = {}
  TITLE_PATTERNS.each do |regexp, symbols_and_lambdas|
    captures = regexp.match(title.to_s)
    if captures
      symbols_and_lambdas.zip(captures[1..-1]).each do |symbol_and_lambda,capture|
        symbol, proc = symbol_and_lambda
        # Many types pass "identity" as the proc; we might as well give
        # them a shortcut to delivering that without the extra cost.
        # 
        # Especially because the global type defines title_patterns and
        # uses the identity patterns.
        # 
        # This was worth about 8MB of memory allocation saved in my
        # testing, so is worth the complexity for the API.
        if proc then
          h[symbol] = proc.call(capture)
        else
          h[symbol] = capture
        end
      end
      return h 
    end
  end
end

class MatcherTest < Test::Unit::TestCase
  def test_with_conf
    assert_equal({target: '/postgresql.conf', key: 'foo'}, match('/postgresql.conf:foo'))
  end

  def test_without_conf
    assert_equal({key: 'foo'}, match('foo'))
  end
end

$ ruby title_patterns.rb 
Loaded suite title_patterns
Started
Finished in 0.000252056 seconds.
--------------------------------------------------------------------------------------
2 tests, 2 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
100% passed
--------------------------------------------------------------------------------------
7934.74 tests/s, 7934.74 assertions/s