how to set client_max_body_size dynamic for nginx

Question

I want to config dynamically client_max_body_size using a variable in nginx config.

set $max_body 100M; 
client_max_body_size $max_body;

How to patch nginx for this?

Thanks,

Answer 1

You can't.

Directive client_max_body_size doesn't accept variables and is not usable in a if block.