declare type RealipHeader = 'CF-Connecting-IP' | 'X-Forwarded-For' | string;
export default class NginxRealip {
    /**
     * CloudFlare IPs
     */
    private readonly ips;
    /**
     * NGINX `set_real_ip_from` rules.
     */
    protected rules(): Promise<string[]>;
    /**
     * Serialize the given NGINX ruleset.
     *
     * @param rules
     */
    protected serialize(rules: Array<string>): string;
    /**
     * Build NGINX configuration for the given realip header.
     */
    buildConfig(realipHeader?: RealipHeader): Promise<string>;
}
export {};