Nginx: using X-Accel-Expires with Cache-Control

Xavier Lucas 2014-11-02 19:42:37

Then,

Modify the upstream to send X-Accel-Expires header everytime or add it with add_header directive (using for instance $http_cache_control in a if statement).
Ignore Cache-Control header for caching everytime.
Use an upstream block.

map $upstream_http_cache_control $cache_control_value {
    "~^max-age=(?<duration>\d+)$" "$duration";
}

server {

   listen 127.0.0.1:80;

    upstream nodes {
        server foo;
    }

    location / {

        if ($upstream_http_x_accel_expires = '') {
            add_header "X-Accel-Expires" $cache_control_value;
        }

        proxy_set_header "Host" $host;
        proxy_pass http://nodes;
    }

}

server {

   server_name mydomain.com;

   listen X.X.X.X:80;

   upstream intermediate {
       server 127.0.0.1;
   }

   location / {
       proxy_set_header "Host" $host;
       proxy_pass http://intermediate;
       proxy_ignore_headers 'Cache-Control';
       proxy_cache mycache;
   }

}

For the last case refer to the first point or use proxy_cache_valid, but with this last paremeter you can't make the timeout dynamic. You need some coherent workflow at one point.

Tereska 1970-01-01 08:00:00

Thanks for answser but this isnt working. 'if' logic in this case is in action after nginx cache module decided to not to cache response. My upstream returned only: Cache-Control: 60. Nginx added X-Accel-Expires header as it should but there is no file in the cache and clients see both Cache-Control and X-Accel-Expires header in the response. So this is clear that this IF logic is placed after cache logic happens.

Xavier Lucas 1970-01-01 08:00:00

@Tereska Of course, you need to set an intermediate vhost. See updated answer for clarity. But keep in mind that the best way to achieve this is to correct your workflow.

Tereska 1970-01-01 08:00:00

WOW. this is clever :) One more thing: Cache-Control:max-age=60. How to put only value "60" (without maxage=) from Cache-Control to X-Accel-Expires (I'm refering to the IF statement). Without some regexp(?) I will end up with X-Accel-Expires: max-age=60 (and I think this will not work(?))

Xavier Lucas 1970-01-01 08:00:00

@Tereska Use a map statement and capture the right value with a regex.

Tereska 1970-01-01 08:00:00

could you give im some example what do you mean? (it could be in pseudo code if you dont have time). thank you.

Nginx: using X-Accel-Expires with Cache-Control

热门github