Hello

How can I add a header on nginx to show how long the file was cached?

Like Varnish :

Age: 91927

Time value is in seconds

How can I do that?
I could put HIT / MISS using:


add_header X-Cached $upstream_cache_status;

But how can I put how long the object was cached ??? ( eg: $upstream_cache_age ?? )

It is good for debug!