Allow more Cache-Control settings like s-maxage or CDN specific caches

[MarkusWendorf]

Hey there,

I was thinking about setting the Cache-Control header to max-age=86400, s-maxage=31536000.

Meaning:

• Cache the tile in the browser (end user) for 1 day
• Cache the tile in the CDN cache for 365 days

However right it is only possible to set max-age=n via process.env.CACHE_MAX_AGE.

Would it make sense to allow set the Cache-Control header directly? Something like process.env.CACHE_CONTROL.

I would be open to implement this feature. I'm not sure if we should keep the old option and make it backwards compatible.

Thoughts?

[bdon]

What about a second configuration like process.env.CACHE_S_MAXAGE? Though I do agree that if there are even more options people want to customize then setting the CACHE_CONTROL as a single string is much more flexible.

It should be OK to break backwards compatibility right now since the CDN integration code isn't versioned (not sure the best approach here either)

[MarkusWendorf]

I would prefer CACHE_CONTROL over CACHE_S_MAXAGE. It might be useful for some people to use stale-while-revalidate for example.

And I don't see any advantage in being over restricted here.