I have no idea, but it wouldn't be that hard to implemented for this module as our internal configuration parser just saves it to a object so we could just read/save JSON structures if needed. cc @Swaagie

our internal configuration parser

Does it handle full haproxy config syntax parsing and generation to and from JSON already?

Been a while since I worked on this, it already reads from JSON it seems, but that is pretty easy of course https://github.com/observing/haproxy/blob/master/lib/parser.js#L20-L29. That said it keeps track of all values through an object like @3rd-Eden said, so a stringify of the internal representation should be enough. However it will result in a loss of comments as those are not supported by JSON, https://github.com/observing/haproxy/blob/master/lib/parser.js#L64-L66