Caching-Headers for Images are always "no-cache" and "expires: -1"

Question

I'm running a Piranha CMS based page, using it as a content source in passive mode. While working on optimizing pagespeed i saw that all image requests handled by piranha return the following response headers:

GET /media/4b3b3fa3-ff7b-4af7-81f2-168474edd23f/50/20

Cache-Control:no-cache
Content-Length:52826
Content-Type:image/jpeg
Date:Mon, 17 Nov 2014 11:53:28 GMT
Expires:-1
Pragma:no-cache
X-UA-Compatible:IE=Edge,chrome=1

Naturally, i want these images to be cached where possible. I looked around the code on github and saw that this information appears to be set in /Piranha/Web/ClientCache.cs.

Is there a way to influence the caching headers set by piranha?

Answer 1

The configuration section isn't all that clear in the current version but the caching is controlled by two parameters that you can set in the manager interface from System > Parameters. Here you have the two parameters CACHE_PUBLIC_EXPIRES and CACHE_PUBLIC_MAXAGE which specifies the time, in minutes, of the client browser cache.

These are set to 0 by default since you don't want cache enabled during development which disables the cache and renders the no-cache headers. When you activate the cache E-tag, Last modified & Expires headers will be generated for your media files.

Best regards

Håkan