Breaking: #93048 - Backend URL rewrites

See Issue #93048

Description

To introduce human readable urls to the TYPO3 backend, a new rewrite rule for the backend is necessary. Therefore the rewrite process should not longer be stopped if the typo3/ directory is accessed, like it was configured for a long time. Instead, all requests below /typo3/ which do not exist, are now redirected to the TYPO3 Backend entry point.

Further do the Backend URLs now not longer require the &route= parameter since its value is now part of the URL. For example the main entry point changed from /typo3/index.php?route=%2Fmain to /typo3/main.

The &route= parameter will however be still applied to the URL for backwards compatibility.

Impact

Accessing the backend without changing the webserver configuration will usually lead to a 404 - Not found response.

Custom backend links which are not build using the UriBuilder API also may lead to a 404 - Not found response.

Using relative paths for backend links, e.g. for icons / images, will may not longer work as expected.

Extensions relying on the &route= parameter to be set will still work but break at least in v12 when this parameter will finally be removed.

Affected Installations

All installations are affected.

Migration

There is a silent update in place which automatically updates the webserver configuration file when accessing the install tool, at least for Apache and Microsoft IIS webservers.

Note: This does not work if you are not using the default configuration, which is shipped with Core and automatically applied during the TYPO3 installation process, as basis. No worries, some custom adjustments like redirects do not prevent the update. Only the default rewrite rules must be in place.

If you however use a fully custom configuration, especially when using a custom entry point for the backend, you may have to perform the necessary changes manually. Therefore, please have a look at the changes to the default .htaccess configuration, for reference.

Apache Config before:

RewriteRule ^(?:typo3/|fileadmin/|typo3conf/|typo3temp/|uploads/) - [L]

Apache Config after:

RewriteRule ^(?:fileadmin/|typo3conf/|typo3temp/|uploads/) - [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-l
RewriteRule ^typo3/(.*)$ %{ENV:CWD}typo3/index.php [QSA,L]

For Nginx, add following block:

location /typo3/ {
    absolute_redirect off;
    try_files $uri /typo3/index.php$is_args$args;
}

Additionally, make sure to use the public UriBuilder API for all custom generated backend links.

Finally, check custom backend modules for the use of relative paths, because they may not longer work as expected.