In a current setup where nginx acts as a reverse proxy to some Apaches I want to deny access to some useless Flotsam & Jetsam files.
What I not want is to craft wonderful regular expressions that suffice type 3 of a Chomsky-Hierarchy while learning about Pumping-Lemmata, albeit that sounds very alluring for an annoyingly hot summerday later this year (Todo).
So in order to keep my various location directives specific as they are I create a map like this (example):
map $uri $reqhide {
default 0;
"~*robots.txt$" 0;
"~*\.(md|txt)$" 1;
"~*liesmich\.html$" 1;
}
This map has to be created in the http context of a config file and can then be used in if-conditions within location blocks. It uses the special parameter default to set the variable $reqhide in case of any non-matching pattern. If I want to hide files later on like all .txt files I set $reqhide to 1. A request for „robots.txt“ is caught by the first matching regular expression, so a request for „foo.txt“ is caught by the second that goes for all .txt files. The complete order of priority is explained in the map-module-docs.
As this wonderfully unknown (to many) article on nginx.com notes, the only 100% safe things in if conditions are return and rewrite statements.
So I just do something like
location / {
[...]
if ($reqhide) {
return 404;
}
[...]
}
to make the response a 404-File-not-found lie.
