Nginx perl JWT claim logging

nginx.conf

load_module   "modules/ngx_http_perl_module.so";

http {
    perl_modules perl/lib;
    perl_set $jwt_value "sub {
        use strict;
        use warnings;

        my $r = shift;
        my $jwt = $r->header_in('Authorization');
        $jwt =~ s/^Bearer //;
        my $payload = (split(/\./, $jwt))[1];

        return $payload;
    }";

    perl_set $claim_value "sub {
        use strict;
        use warnings;

        use MIME::Base64 qw(decode_base64url);
        use JSON::PP;

        my $r = shift;
        my $payload = $r->variable('jwt');
        my $json = decode_json(decode_base64url($payload));
        my $claim = exists $json->{email} ? $json->{email} : exists $json->{uid} ? $json->{uid} : exists $json->{tgid} ? $json->{tgid} : $json->{sub};

        return $claim;
    }";

    map $http_authorization $jwt {
      ~. $jwt_value;
      default -;
    }

    map $http_authorization $claim {
      ~. $claim_value;
      default -;
    }

    log_format  main  '$msec $remote_addr - $remote_user "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" $server_name $request_time $claim $jwt';
}