Nginx try_files remove client_max_body_size option - nginx

Question

I have a trouble to setup my nginx.conf for my symfony application. I want to setup a route /section/upload/ that allows to increase the size of the client_max_body_size (~100M, standard client_max_body_size = 25M)
http {
### ....
client_max_body_size 25M;
server {
location / {
try_files $uri /index.php$is_args$args;
location /section/upload {
client_max_body_size 100M;
try_files $uri /index.php$is_args$args;
}
}
location ~ ^/index\.php(/|$) {
fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
fastcgi_split_path_info ^(.+\.php)(/.*)$;
include fastcgi_params;
### ... specific fastcgi_param needed by my symfony application
### like : fastcgi_param APP_ENV prod;
}
}
}
I get an error when I send a file larger than 25M on the /section/upload route. To avoid this I have to put the parameter client_max_body_size=100M in location ^/index.php(/|$).
I think try_files doesn't follow my client_max_body_size, is it normal and is it good/safe to setup like that ?

Answer 1

The try_files directive rewrites the URI to /index.php which is then processed in a different location. To set a different value for client_max_body_size, you will need to process /index.php within the location /section/upload block.
For example:
location / {
try_files $uri /index.php$is_args$args;
}
location /section/upload {
client_max_body_size 100M;
try_files /index.php =404;
fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
include fastcgi_params;
}
location ~ ^/index\.php(/|$) {
fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
fastcgi_split_path_info ^(.+\.php)(/.*)$;
include fastcgi_params;
}
The try_files statement is changed so that /index.php appears as a file parameter and not a URI parameter. Most of the FastCGI directives are also required. See this document for details.