Cache images and CSS in the node server

[dessalines]

I'd thought we'd had this, but I guess not.

@miyurusankalpa would you be able to help with this one?

Context LemmyNet/lemmy-ansible#75

[Nutomic]

For this it would be really helpful if lemmy and lemmy-ui can set proper cache-control headers. Like setting private when its an authenticated user, and in case of static assets it can set etag.

[dessalines]

In that case I'll transfer this to lemmy-ui, since its embedded node server should do that caching.

[Nutomic]

It doesnt need to do any caching on its own, just set the correct HTTP headers. Then admins can configure caching in nginx or another reverse proxy based on their requirements. Browsers also do caching based on these headers.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag