Add `cache_whitelist` config option

[xtrasimplicity]

Background

Currently, for a URL to be cacheable, it must have a cacheable HTTP response code and:

• Must be a non-whitelisted URL, or
• Must be a blacklisted path

The problem with this is that sometimes you may want to force a whitelisted host to also be cacheable. For example, in one application I'm working on, I'd like to block all external requests using c.non_whitelisted_requests_disabled, but allow specific hosts to be cached so that I can use Puffing-Billy as I would VCR.

Logically, when using c.non_whitelisted_requests_disabled only whitelisted requests are enabled. Unfortunately, however, whitelisted URLs are never cached, so I have two options: 1) Set c.non_whitelisted_requests_disabled to false and cache all requests, OR 2) Abandon my plan to use Puffing-billy as I would VCR, and just stub requests manually.

Solution

• Added a cache_whitelist config option which functions in the same way as whitelist.
• When determining whether a request is cacheable, the Proxy Handler now takes into account whether the URL is in the c.cache_whitelist array.

[xtrasimplicity]

Hey, @ronwsmith - apologies for the ping, but just wanted to see if this is something that you'd be open to, or if there's another way you'd prefer this be handled? Thanks!

[ronwsmith]

@xtrasimplicity this change looks good to me. I'm thinking we need to soon change the variable names as it hurts my head thinking about this logic now :) May be a little over a week before I get this in.

[ronwsmith]

@xtrasimplicity released in v2.3.0

[xtrasimplicity]

Thanks, @ronwsmith!