NGINX specify variable for specific directory and index file only - regex

Question

I am using fastcgi caching, and would like to specify which URLs the cache should be active on.
I use a rewrite rule to determine which controller file to access, and set any query parameters dynamically
I want to specify URLs in which the cache is activated, and those in which it is inactive, this is my code:
server {
listen 80;
server_name domain.com;
root /home/site/wwwroot;
set %skip_cache 1; #this is the variable that I want to set to 0 on specific URLS
location / {
try_files $uri $uri/ $uri.html #php;
}
location #php {
rewrite ^(/[^/]+)$ $1.php last;
rewrite ^(/[^/]+)/(.*)$ $1.php?q=$2 last;
}
location /user/ {
set $skip_cache 0;
}
location /objects/ {
set $skip_cache 0;
}
location ~ \.php$ {
try_files $uri =404;
include fastcgi_params;
fastcgi_pass unix:/run/php/php7.0-fpm.sock;
fastcgi_split_path_info ^(.+?\.php)(/.*)?$;
fastcgi_connect_timeout 300;
...etc...
#cache parameters
fastcgi_param FASTCGI_CACHE 1;
fastcgi_cache cfcache;
fastcgi_cache_valid 30s;
fastcgi_cache_bypass $skip_cache;
fastcgi_no_cache $skip_cache;
add_header X-FastCGI-Cache $upstream_cache_status;
}
as you can see, the variable $skip_cache is set to 1 by default, and I would like to white list URLs for caching.
An example I would like cached is domain.com, domain.com/user/123 and domain.com/objects/456
Currently, if I browse to /user/123, the result is a 404 error, as I believe that location block with the variable setting is being used exclusively.

Answer 1

If you want to set a variable based on the original request, you should use a map directive with the $request_uri variable. See this document for details.
For example:
map $request_uri $skip_cache {
default 1;
~^/user/ 0;
~^/objects/ 0;
}
server {
...
fastcgi_cache_bypass $skip_cache;
fastcgi_no_cache $skip_cache;
...
}