Hello! On Thu, Jul 05, 2018 at 05:44:00PM -0700, Dk Jack wrote:
> Hi, > I have an nginx module. The purpose of my module is to inspect every > request and make a binary decision (i.e drop or allow). When dropping, I am > sending a custom status code and response message. I've setup my module > handler to be called in the NGX_HTTP_REWRITE_PHASE. Things seem to be > working fine for the most part except for a small issue. > > I am seeing 'header already sent' messages in the nginx error.log. In my > handler, I create a context for my module and attach it request using > the ngx_http_set_ctx call. I am using the context to store some info and > also to prevent my module from processing the same request multiple times. > My module processes the request only once. > > I get the 'header already sent' message only for a fraction of the > requests. The messages seem to be generated only for requests that I > allowed in my module. In my module handler, I return an NGX_DECLINED return > code when I allow a request. The message is not generated for every allowed > request but only for some of the allowed requests. When the error is > generated it is always for POST request and not all POST requests cause > this error message to be logged. > > Could someone explain what could be going on here or where I should look at > next to debug this further? Any pointers are appreciated. Thanks. The "header already sent" alert indicate that there is a serious bug somewhere, resulting in an attempt to send a response header second time. If you see it for POST requests handled by your module, it likely means that you are handling requests with bodies incorrectly. -- Maxim Dounin http://mdounin.ru/ _______________________________________________ nginx-devel mailing list nginx-devel@nginx.org http://mailman.nginx.org/mailman/listinfo/nginx-devel
