NGINX - dynamically created proxy

I have HTTP API, that provides some historic values using URL that contains UNIX timestamp as selector. Example: http://apiserver.org/api/1664269800/value

The timestamp value must be one of 10minutes granularity, eg: 10:10:00, 10:10:10 transformed to timestamp

I need to implement "latest" functionality,

I have simple nginx configuration, the wanted functionality is that access to "/proxyredir" will pass to http://apiserver.org/api/1664269800/value/, where timestamp number is dynamically computed.

location /proxyredir/ {
    proxy_pass http://apiserver.org/api/1664269800/value/;
}

And I need some magic to compute timestamp value dynamically, get actual datetime, truncate to 10min granularity and perform proxypass.

I studied nginx perl module https://nginx.org/en/docs/http/ngx_http_perl_module.html?_ga=2.25112314.176064600.1664266760-2134269433.1664266760 but without success.

Please any ideas how to solve this problem?

CodePudding user response：

Problem solved using nginx perl module. The trick is that set_perl directive must be defined in configuration toplevel "http" but this variable is reevaluated on every request if used in "location contex"

The configuration looks like:

http {
  ...
  perl_set $tstamptrunc '
                sub {
                        my $r = shift;
                        # UNIX TIMESTAMP trucated to 10minutes
                        $epoch_10m_trunc = int(time()/600)*600;
                        return "$epoch_10m_trunc";
                }
        ';


...

  location ~ /api/latest/(. ) {
    resolver 8.8.8.8;
    proxy_pass: https://remote.org/api/$tstamptrunc/$1;
  }
}

The resolver definition is necessary if proxy_pass definition is dynamically defined.