More on Static file redirector

So On a previous blog entry http://www.makina-corpus.org/blog/use-rewritemap-prevent-proxying-some-s... I presented the base for a rewriteRule settings to serve some targeted plone static files directly from apache and without proxying to Plone. No let's make this solution even better. * use a hash map for url mappings * create a virtual /static url and apply some cache managment rules on his contents * allow the use of the /satic/ url directly * ensure only mapped static files are served via this static directory So first thing to change, we used a simple text file for the mapping, mod_rewrite allows us to use a hash file. Simply change:

RewriteMap statics txt:/var/www/proxyplone/etc/staticplonefiles.txt

by

#RewriteMap statics txt:/var/www/proxyplone//etc/staticplonefiles.txt
# to generate hash version of previous file use (do not forget the rm):
# rm /var/www/proxyplone//etc/staticplonefiles.map; 
# httxt2dbm -i /var/www/proxyplone/etc/staticplonefiles.txt -o /var/www/proxyplone/etc/staticplonefiles.map
RewriteMap statics dbm:/var/www/proxyplone/etc/staticplonefiles.map

And to generate the .map file simply read the comments. One important point, if you do not remove the old map before generating the new one, old entries are still in the .map, to see it without too much garbage use :

strings /var/www/proxyplone/etc/staticplonefiles.map

Ok, so now let's look the current RewriteRule, for matched elements the rewrite is done and the file is directly served. We xould like to add some apache settings to theses files, the solution is to add the [PT] (pass-through) option to the rewrite rule. Then Apache will continue to analyse the resulting url as if it were an original requested url. That mean the proxy settings for example will be applied on it. So we will as well add a /satic on the resulting url and prevent /static to be served by the Proxy. The rewriteRule is now:

RewriteRule ^/(.*\.(ico|png|gif|jpg|jpeg|bmp|css|js)) /static/${statics:$1} [NC,L,handler=default-handler,PT]

And we add this ProxyPass exception:

ProxyPass       /static  !

We now have a virtual /static directory with all theses mapped contents inside. We can use it to getBack the original DocumentRoot, and to use an alias to point /static to our webapp sources (here /opt/plone/source). And then we can add Expires settings from mod_expires on this /static location... well in fact mod_expires requires a Directory directive so it will be on the /opt/plone/source directory. Reset DocumentRoot:

DocumentRoot /var/www/proxyplone/htdocs

Remove this line:

Alias / /opt/plone/source/

And add theses settings:

    Alias /static /opt/plone/source/
    <Location /static>
        Options FollowSymLinks
        Order deny,allow
        Allow from all
        DirectoryIndex index.html
        # avoid execution of PHP  scripts 
        AddType text/plain .php
        AddType text/plain .php3
        AddType text/plain .phps
    </Location>
    # adding some cache handling for static files
    <Directory /opt/plone/source>
        order allow,deny
        allow from all
        ExpiresActive On
        ExpiresDefault "access plus 1 month"
        ExpiresByType text/css "access plus 1 day"
        ExpiresByType text/javascript "access plus 1 day"
    </Directory>

That's done. Now we have a big security Hole :-(. Most files from /opt/plone/source are available via the /static url. As /static is not proxied anymore and is now an alias on the fielsystem directory where we have an allow from all... So we should add some rewriteRules to check which files are allowed via direct access on static. And by default it should be none. But that's sad, it would be nice to promote good behaviour for theses wtf programmers which aren't admins, we should let them use /static urls for files known to be static. And maybe one day they'll think it's a good idea to make the distinction between known static files and dynamic content... So we'll ask developpers to add some entries in the staticplonefiles.txt making a mapping from static/files to real files this way:

# staticplonefiles.txt
# url => real filesystem file, from an arbitray root
zonea/images/clean.png foo/bar/img/clean.png
/static/foo/bar/img/clean.png foo/bar/img/clean.png
zonea/images/logo.jpg foo/src/module/foo/images/logo.png
/static/foo/src/module/foo/images/logo.png foo/src/module/foo/images/logo.png
/module/bar/images/people.png foo/src/module/bar/v1.2.5-5/images/people.png
/static/foo/src/module/bar/v1.2.5-5/images/people.png foo/src/module/bar/v1.2.5-5/images/people.png
# ... to be continued

And now our 3 static examples are available as well with the /static url. Well in fact do not forget to add this rule:

# Security for uri containing our /static shortcut we should check only listed files from rewritemap are served, as
# in this current case the static directory contins as well some unsecure files... yep.
RewriteCond %{REQUEST_URI} ^/static/ [NC]
RewriteCond ${statics:$1} =""
# F : force forbidden 403 response
RewriteRule ^(.*)$ - [F,L]

This will check that all directly accessed files via /static are present in our mapping. And it's all done. Like for the previous post you should really activate RewriteLog and look at what he does for several different files, but now you should as well adjust Apache logLevel for this VirtualHost and check the errorLog to observe what is done After the rewrite. As an example of debug here are some debug outputs for: * a matched image

(2) init rewrite engine with requested uri /images/people.png
(3) applying pattern '^/(.*\.(ico|png|gif|jpg|jpeg|bmp|css|js))' to uri '/images/people.png'
(6) cache lookup FAILED, forcing new map lookup
(5) map lookup OK: map=statics[dbm] key=images/people.png -> val=test/img/clean.png
(4) RewriteCond: input='test/img/clean.png' pattern='!=' => matched
(5) cache lookup OK: map=statics[dbm] key=images/people.png -> val=test/img/clean.png
(2) rewrite '/images/people.png' -> '/static/test/img/clean.png'
(2) remember /static/test/img/clean.png to have Content-handler 'default-handler'
(2) forcing '/static/test/img/clean.png' to get passed through to next API URI-to-filename handler
(1) force filename /tmp/htdocs/test/img/clean.png to have the Content-handler 'default-handler'

* index.php which wont be proxified after

(2) init rewrite engine with requested uri /index.php
(3) applying pattern '^/(.*\.(ico|png|gif|jpg|jpeg|bmp|css|js))' to uri '/index.php'
(3) applying pattern '^(.*)$' to uri '/index.php'
(4) RewriteCond: input='/index.php' pattern='^/static/' [NC] => not-matched
(1) pass through /index.php

* the / base uri, which will be proxified

(2) init rewrite engine with requested uri /
(3) applying pattern '^/(.*\.(ico|png|gif|jpg|jpeg|bmp|css|js))' to uri '/'
(3) applying pattern '^(.*)$' to uri '/'
(4) RewriteCond: input='/' pattern='^/static/' [NC] => not-matched
(1) pass through /

* a not mapped image

(2) init rewrite engine with requested uri /images/crystal/32/personal.png
(3) applying pattern '^/(.*\.(ico|png|gif|jpg|jpeg|bmp|css|js))' to uri '/images/crystal/32/personal.png'
(6) cache lookup FAILED, forcing new map lookup
(5) map lookup FAILED: map=statics[dbm] key=images/crystal/32/personal.png
(4) RewriteCond: input='' pattern='!=' => not-matched
(3) applying pattern '^(.*)$' to uri '/images/crystal/32/personal.png'
(4) RewriteCond: input='/images/crystal/32/personal.png' pattern='^/static/' [NC] => not-matched
(1) pass through /images/crystal/32/personal.png

* a direct access via /static for a forbidden file

(2) init rewrite engine with requested uri /static/config/config.ini
(3) applying pattern '^/(.*\.(ico|png|gif|jpg|jpeg|bmp|css|js))' to uri '/static/config/config.ini'
(3) applying pattern '^(.*)$' to uri '/static/config/config.ini'
(4) RewriteCond: input='/static/config/config.ini' pattern='^/static/' [NC] => matched
(6) cache lookup FAILED, forcing new map lookup
(5) map lookup FAILED: map=statics[dbm] key=/static/config/config.ini
(4) RewriteCond: input='' pattern='=' => matched
(2) forcing responsecode 403 for /static/config/config.ini

Quite readable isn't it? But do not forget to remove debug for production env.

Follow me also on regilero.github.io.

Votre notation : Aucun Moyenne : 5 (3 votes)

Thanks, very useful !

It really helps me today !
Thanks, continue !