Probe file system for lowercase filenameby Read Write Tools
|The incoming request path is examined for uppercase letters and the file system is probed with its equivalent lowercase name. If the equivalent filename exists, return with a status code of |
Filenames on Windows are case insensitive, so a request for
hello-world.html are equivalent. Not so on Linux. These are recognized as two distinct files. Neither way is "right", but moving from one file system to another with names like this is problematic.
Because of this, it has become customary to restrict URL paths to be all lowercase. Websites that started out on a case insensitive file system and were later moved to a case-sensitive file system, may break when external hyperlinks point to the incorrectly cased filename. One solution is to rename all filenames to their lowercase equivalent, and use this plugin to instruct browsers of the change.
The algorithm is straightforward:
- Check the file system to see if the requested resource path exists; if so, skip the remaining steps and resume standard processing.
- Apply a lowercase filter to the full resource path and filename.
- Probe the file system to see if the lowercased version exists:
- If so, return with
302 Foundand a
locationheader containing the correct resource path.
- If not, return with
404 Not Found.
This plugin is open source and can be modified or enhanced to perform tasks such as these:
- Safely reorganize the directory structure of your website, without unnecessarily breaking external links.
- Define a lookup table with original filenames and archived filenames, where access to archived content is behind a paywall.
The plugin module is available from NPM. Before proceeding, you should already have
RWSERVE configured and tested.
This module should be installed on your web server in a well-defined place, so that it can be discovered by
RWSERVE. The standard place for public domain plugins is
npm install rwserve-lowercase
Configuration is Everything
Make the software available by declaring it in the
plugins section of your configuration file. For detailed instructions on how to do this, refer to the plugins documentation on the
Read Write Tools HTTP/2 Server website.
`*` *methods=GET,HEAD *plugin=rwserve-lowercase
router shown above will route all requests (
HEAD methods, to the plugin.
A full configuration file with typical settings for a server running on localhost port 7443, is included in this NPM module at
etc/lowercase-config. To use this configuration file, adjust these variables if they don't match your server setup:
Once you've tested the plugin and are ready to go live, adjust your production web server's configuration in
/etc/rwserve/rwserve.conf and restart it using
systemd. . .
[user@host ~]# systemctl restart rwserve
. . . then monitor its request/response activity with
[user@host ~]# journalctl -u rwserve -ef
This is a plugin for the Read Write Tools HTTP/2 Server, which works on Linux platforms. Windows, MacOS and BSD are not supported.
|This plugin demonstrates a basic pattern that many plugins follow: |
The rwserve-lowercase plugin is licensed under the MIT License.
Copyright © 2020 Read Write Tools.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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