nginx过滤access_log中HEAD、OPTIONS请求记录

网上很多教程说是这样做：

if ($request_method = HEAD) {
    access_log off;
}

试了之后是不行的，正确的做法如下：

http {
    map $request_method $loggable {
        HEAD 0;
        OPTIONS 0;
        default 1;
    }

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /usr/local/openresty/server/nginx/logs/access.log  main if=$loggable;
}

这里过滤掉了HEAD和OPTIONS请求

官方文档地址：http://nginx.org/en/docs/http/ngx_http_log_module.html