*This page describes how to use Apache's mod_rewrite module with WebKit_, and mod_webkit in particular. It starts with a general overview and then presents some recipes for solving specific problems.* Overview -------- Related reading: `mod_rewrite reference docs`_, `mod_rewrite guide`_ .. _mod_rewrite reference docs: http://httpd.apache.org/docs/mod/mod_rewrite.html .. _mod_rewrite guide: http://httpd.apache.org/docs/misc/rewriteguide.html *mod_rewrite* is an Apache module that is used to remap URLs. Here's how the Apache manual describes it: This module uses a rule-based rewriting engine (based on a regular-expression parser) to rewrite requested URLs on the fly. It supports an unlimited number of rules and an unlimited number of attached rule conditions for each rule to provide a really flexible and powerful URL manipulation mechanism. The URL manipulations can depend on various tests, for instance server variables, environment variables, HTTP headers, time stamps and even external database lookups in various formats can be used to achieve a really granular URL matching. It is an incredibly flexible tool that can be used for a wide range of tasks. Here's some examples: * change the file layout of your site without breaking bookmarked or search-engine indexed URLs * make a certain directory or file visible in every subdirectory of your site without needing to symlink to it in every subdir or manage complex relative paths. * use mod_webkit to serve files that appear to the user as if they are in Apache's top directory ('DOCUMENT_ROOT'). Without mod_rewrite, each URL would look like _www.mysite.com/WK/MyServlet_.py_. With mod_rewrite, you can use a simpler URL like _www.mysite.com/MyServlet_.py_ * redirect to files on remote servers * TestSubject_ To use mod_rewrite you need to compile it with Apache and then enable it in your _httpd.conf_ configuration file. See the apache docs for compilation instructions. To enable it in your _httpd.conf_ file, uncomment or add the following lines to the DSO section in part 1:: LoadModule_ rewrite_module modules/mod_rewrite.so AddModule_ mod_rewrite.c -- TavisRudd_ - 05 Mar 2002 Recipes ------- Hiding the /WK part of an URL when using mod_webkit ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To use ModWebKit_, you'll usually have some lines like this in your ``http.conf``:: WKServer localhost 8086 SetHandler webkit-handler Then /WK/Servlet will run Servlet.py in the default context. The problem with this is that you now have an implementation dependent fragment "WK" (standing for "WebKit_") in your application URLs. This is considered bad for various reasons. Ideally, the URL should only reflect the content and be human readable (you might want to read the passage about `"The right URL for your link"`_ from the Tutorial `"The Care and Feeding of Hyperlinks"`_ ). You cannot simply omit the Location "/WK" or replace it by "/" if you want everything to be served through WebKit_ (I don't know why, but it won't work). However, you could replace "WK" by a memorable and reasonable keyword pointing to the application itself, not the technology behind it. .. _"The right URL for your link": http://www.webreference.com/html/tutorial25/3.html#HEAD-3 .. _"The Care and Feeding of Hyperlinks": http://www.webreference.com/html/tutorial25/ The more sophisticated solution is to map the URL using the URL manipulation capabilities of Apache provided by mod_rewrite. Perhaps you want to map different URLs to different contexts, or even to the root of the website:: RewriteEngine_ On RewriteRule_ ^(.*) /WK/LocalSite_/$1 [L,PT] ## NOTE: put no space between L and PT! The L flag means "this the LAST rule, don't apply any more" and PT means "PASS-THROUGH the changed URI to the next handler." You can leave the L off, but the PT is essential if you are using mod_webkit. See the mod_rewrite reference guide for an explanation. To redirect all images to a static location, so that there's no overhead from calling Webware, you would put this rewrite directive *before* the above:: RewriteRule_ ^(.*\.(jpg|gif|png))$ /images/$1 [L,PT] For a virtual domain, do something like:: ... RewriteEngine On RewriteRule ^(.*)$ /WK/BobsYourUncle/$1 [L,PT] This assumes ``/WK`` (not virtual) is where the AppServer is located, and that you've created a context ``BobsYourUncle`` for that virtual domain. What if you aren't using mod_webkit? Say you are using a CGI adapter at http://mainhost.com/cgi-bin/WebKit.cgi ? Then just replace ``/WK`` with =/cgi-bin/WebKit.cgi`` in all these examples. You can use ``[L]`` instead of ``[L,PT]`` if you aren't using mod_webkit. (Do you need ``[L,PT]`` if you are using mod_snake, etc?) -- IanBicking_ ... with changes by TavisRudd_ - 05 Mar 2002 If the image location is the same as the original URL, use a hyphen as the second argument. You don't need $1's ()s in this case:: RewriteRule_ ^.*\.(jpg|gif|png)$ - [L,PT] -- MikeOrr_ - 10 Dec 2001 I had two problems. The first was that I put my httpd.conf rewrite rules in a such as / or the doc root. This gave either a repeating path that was HTTP Forbidden, or gave no response. The solution was to put the rules above the first . The second problem was that if I put a slash in front of $1, the path could not be found. Finally, I was able to remove the ^ and $, which aren't needed to capture the whole path. My final solution was:: ... DocumentRoot_ "/usr/local/apache/htdocs" RewriteEngine_ On RewriteRule_ (.*) /webkit/ContextName_$1 [L,PT] ... I used Apache 1.3.22 (built from source) on Mandrake Linux 8.1. -- ChuckEsterbrook_ - 22 Jan 2002 I used .htaccess files to set the rewrite rule, and had the following rules as above:: RewriteEngine_ On RewriteRule_ ^(.*\.(jpg|jpeg|gif|png)) /images/$1 [L,PT] RewriteRule_ ^(.*) /cgi/OneShot_.cgi/MyContext_/$1 [L,PT] This caused the recursion mentioned above in another case, to solve this I went to /cgi/.htaccess and placed there:: RewriteEngine_ Off This solved it. Now I can get to actually try to build my application. -- BaruchEven_ - 17 Feb 2002 To clarify, if you want Webware to serve URLs in the top-level directory (/index.py) without a /WW prefix *AND* serve certain files statically:: 1 RewriteRule_ ^/images(.*) - [L] 2 RewriteRule_ ^/pix/(images|thumbs)/(.*) - [L] 3 RewriteRule_ ^/WW($|/.*) - [L] 4 RewriteRule_ ^(.*) /WW/$1 [L,PT] (The line numbers are not in the Apache file.) (1) and (2) rewrite /images, /pix/images and /pix/thumbs to their original URLs ("-") and use "L" to prevent rule 4 from executing. (3) rewrites URLs with the WebKit_ prefix to their original URLs, and uses "L" to prevent 4 from executing, which would wrongly rewrite /WW/index.py to /WW/WW/index.py (4) does most of the work, rewriting /index.py to /WW/index.py so that users don't have to type the /WW prefix. "PT" is necessary or the request won't be passed properly to WebKit. I don't know if it's possible to make WebKit_ serve directly from / using *AND* serve some files statically. If it were possible, you'd need to supercede the "SetHandler webkit-handler", thus:: WKServer localhost 8086 SetHandler_ webkit-handler SetHandler_ apache-core-default-handler but I don't know how you set the handler back to the default once you've set it to something else. -- MikeOrr_ - 16 Apr 2002 Hiding the /WK using ModPython in a Virtual Host ------------------------------------------------ My server is hosting 3 unrelated URLs. Each URL resolves to a virtual host. One of these virtual hosts is used as the example. The Apache config for the Virtual Server includes both the Location directive as well as the RewriteRule_ directives. This allows for different configs for each of the three virtual hosts. The RewriteRules_ accomplish two things. One, the third rule adds the "/wk" to the start of the URL passed to Apache. This makes Webware happy. However, the first rule ensures that a "/wk" does not already exist in the URL, as two "/wk" values would be a problem. Two, the second rule sends request for images used by mywebcontext to the proper non-context directory. The "[L,PT]" on both the second and third rules allows only one of those rules to be processed. Given the server directory structure:: /pub /httpd /myweb /mywebcontext /mywebimages The Webware context is:: 'Contexts': {'mywebcontext':'/pub/httpd/myweb/mywebcontext', 'default':'mywebcontext'} The Apache config is:: DocumentRoot_ /pub/httpd/myweb ServerName_ www.e-myweb.com # # Added For WebWare_ / WebKit_ Support # RewriteEngine_ On RewriteRule_ ^/wk/(.*) /$1 [R] RewriteRule_ ^/images/(.*) /mywebimages/$1 [L,PT] RewriteRule_ ^/(.*) /wk/$1 [L,PT] SetHandler_ python-program # add the directory that contains ModPythonAdapter_.py PythonPath_ "sys.path+['/usr/local/Webware/WebKit_']" PythonOption_ AppWorkDir_ /pub/httpd/myweb PythonHandler_ ModPythonAdapter_ PythonDebug_ On -- TacticalJack_ - 04 Sep 2002