<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, 10 Jul 2020 at 02:44, Brad Wood <<a href="mailto:bdw429s@gmail.com">bdw429s@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">So, in my bid to put the predicate language through the paces, I've been testing out all the rewrite rules I've ever used with mod_rewrite or Tuckey Rewrite to see if Undertow's handlers are up to the task. <div><br></div><div>I've run into an issue again with probably the most common rewrite rule of any CFML app using an MVC framework, which is a rule that creates so-called "SES" URLs and force all requests through a front controller design pattern. </div><div><br></div><div>Basically</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><font face="monospace"><a href="http://site.com/home/about" target="_blank">site.com/home/about</a></font></blockquote><div><br></div><div>gets rewritten to</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><font face="monospace"><a href="http://site.com/index.cfm/home/about" target="_blank">site.com/index.cfm/home/about</a></font></blockquote><div><br></div><div>Here you can see how this rule is typically accomplished in Apache httpd, Nginx, IIS, and Tuckey:</div><div><br></div><div><a href="https://coldbox.ortusbooks.com/the-basics/routing/requirements/rewrite-rules" target="_blank">https://coldbox.ortusbooks.com/the-basics/routing/requirements/rewrite-rules</a> </div><div> <br></div><div>The hang up is that<i> any incoming path that maps to an actual file</i> skips the rewrite rule. That way<b> /images/logo.jpg</b> doesn't get rewritten. </div><div><br></div><div>So here was my first stab at it with Undertow's predicate language-- it seemed simple enough:</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><font face="monospace">not file and not directory -> rewrite('/index.cfm/%{RELATIVE_PATH}')</font></blockquote><div><br></div><div>But our old friend the servlet of course is nowhere to be found since my "file" and "directory" predicates were executing in the root handler chain so there is no concept of a servlet's context root with which to resolve file system paths. </div><div><br></div><div>So basically, I understand exactly why this doesn't work, but I feel that we need to find a way to make this work. This is a feature that pretty much every rewrite engine I've ever used has-- the ability to test the file system to see if a file or directory exists. Can we discuss the following options?</div><div><ul><li>Find a way for the root handler chain to access the deployment's resource manager </li></ul></div></div></blockquote><div><br></div><div>The big conceptual problem here is that there can be multiple Servlet deployments, and the rewrite could change which deployment actually gets served by the request. You could write a custom predicate to handle this, but you would need to stick the Servlet deployment in a static variable so the PredicateBuilder has access to it. We could do it with some API changes I guess, have the PredicateBuilder accept a Map<String, Object>, so you could pass in the ServletContext as you are building the predicates.<br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><ul><li>Find a way for the rewrite handler to correctly affect not only the exchange but also (optionally) the HttpServletRequest so it's possible to rewrite the URL inside of the servlet's handler chain. I know for certain this is possible because the Tuckey Rewrite engine is implemented as a servlet filter.</li></ul></div></div></blockquote><div>This would be done using RequestDispatcher.forward(), you could write a handler that uses this, or you could write one that uses the Undertow specific io.undertow.servlet.api.Deployment#getServletDispatcher() to re-dispatch without calling forward. <br></div><div><br></div><div>Stuart<br></div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><div><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div>I would prefer the first option since I do like having the predicates in the root handler chain so it can run as early as possible.</div><div><br></div><div>Thanks!</div><div><br></div><div>~Brad</div><div><br></div><div><b>Developer Advocate</b></div><div><i>Ortus Solutions, Corp </i></div><div><b><br></b></div><div>E-mail: <a href="mailto:brad@coldbox.org" target="_blank">brad@coldbox.org</a></div><div>ColdBox Platform: <a href="http://www.coldbox.org" target="_blank">http://www.coldbox.org</a> </div><div>Blog: <a href="http://www.codersrevolution.com" target="_blank">http://www.codersrevolution.com</a></div><div><br></div></div></div></div></div></div></div></div>
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