Remove query parameter

[Ole Laursen]

Barry Abrahamson <barry at ...> writes:

> On Jun 16, 2010, at 11:28 PM, Igor Sysoev wrote:
> 
> > There is no way to remove a parameter, however, you can to define
> > cache key without a query string at all or with predefined parameters only:
> > 
> >       proxy_cache_key   $proxy_host$uri;
> > or
> >       proxy_cache_key   $proxy_host$uri?$arg_one&$arg_two;
> 
> The ability to blacklist specific args from the cache key would be a nice
feature :)

Indeed. Thanks for the answers!

I've figured out how to do remove parameters with the set $args syntax, it's not
pretty though. Would be trivial to do with a parser, but less trivial with
regexp, I basically remove each unwanted GET parameter one-by-one and then fixup
any stray & afterwards:

        # remove GET parameters
        if ($args ~ (.*)utm_source=[^&]*(.*)) {
                set $args $1$2;
        }
        if ($args ~ (.*)utm_medium=[^&]*(.*)) {
                set $args $1$2;
        }
        if ($args ~ (.*)utm_campaign=[^&]*(.*)) {
                set $args $1$2;
        }
        if ($args ~ (.*)gclid=[^&]*(.*)) {
                set $args $1$2;
        }
        # cleanup any repeated & introduced 
        if ($args ~ (.*)&&+(.*)) {
                set $args $1&$2;
        }
        # cleanup leading &
        if ($args ~ ^&(.*)) {
                set $args $1;
        }
        # cleanup ending &
        if ($args ~ (.*)&$) {
                set $args $1;
        }

Then proxy_pass and proxy_cache_key must reference $args, thankfully $is_args
appears to work even when changing $args above :)

        location / {
                proxy_pass      http://127.0.0.1:1234$uri$is_args$args;
                proxy_cache_key "$scheme$host$uri$is_args$args";
                ...
        }


Ole