query string matching in nginx

nginx

map $query_string $new_url {

    ~a=1                                        http://www.gov.uk/1;
    ~a=2                                        http://www.gov.uk/2;
    ~a=3&b=1|b=1&a=3                            http://www.gov.uk/31;
    ~\ba=4\b.*\bb=2\b|\bb=2\b.*\ba=4\b          http://www.gov.uk/42;
}

server {
    server_name     lrc.businesslink.gov.uk;

    location = / { return 301 https://www.gov.uk; }

    # 301 Moved Permanently
    if ( $new_url ) { 
        return 301 $new_url;
    }

    location / {
        # if not / and not a matching redirect, try static assets, else 404
        try_files $uri $uri.html = 404;
        add_header 'cache-control' 'max-age=86400';
    }
}

test-log.pl

#!/usr/bin/env perl

use strict;
use Text::CSV;
use HTTP::Request;
use LWP::UserAgent;
use URI;
use Test::Simple;

my $redirector_host = "http://localhost";

my $ua = LWP::UserAgent->new( max_redirect => 0 ),

my $csv = Text::CSV->new( { binary => 1 } );
my $fh = *STDIN;
my $names = $csv->getline( $fh );
$csv->column_names( @$names );

while (my $row = $csv->getline_hr($fh)) {

        my ($url, $location, $status, $count, $meta) = (
                $row->{'Old Url'},
                $row->{'New Url'},
                $row->{'Status'},
                $row->{'Count'},
                $row->{'Whole Tag'},
        );

        my $uri = URI->new($url);

        my $request = HTTP::Request->new('GET', "http://localhost" . $uri->path_query);
        $request->header( 'Host', $uri->host );

        my $response = $ua->request($request);

        ok($response->code eq $status, "$url status $status [" . $response->code . "]");

        if ($location) {
                ok($response->header('location') eq $location, "$url location [" . $response->header('location') . "]" );
        }
}

tests.csv

Old Url,New Url,Status,Count,Whole Tag
http://lrc.businesslink.gov.uk/?a=1,http://www.gov.uk/1,301
http://lrc.businesslink.gov.uk/?a=2,http://www.gov.uk/2,301
http://lrc.businesslink.gov.uk/?a=3&b=1,http://www.gov.uk/31,301
http://lrc.businesslink.gov.uk/?b=1&a=3,http://www.gov.uk/31,301
http://lrc.businesslink.gov.uk/?foob=2&a=4000,https://www.gov.uk,301
http://lrc.businesslink.gov.uk/?a=4&b=2,http://www.gov.uk/42,301
http://lrc.businesslink.gov.uk/?b=2&a=4,http://www.gov.uk/42,301
http://lrc.businesslink.gov.uk/?a=4&b=2&c=3,http://www.gov.uk/42,301
http://lrc.businesslink.gov.uk/?_=9&a=4&b=2&c=3,http://www.gov.uk/42,301
http://lrc.businesslink.gov.uk/?_=9&a=4&x=99&b=2&c=3,http://www.gov.uk/42,301
http://lrc.businesslink.gov.uk/?_=9&a=4&x=99&b=2&c=3,http://www.gov.uk/42,301
http://lrc.businesslink.gov.uk/?_=9&b=2&x=99&a=4&c=3,http://www.gov.uk/42,301