Posting a form results in 502 error on PHP, nginx and xdebug

This error broke my head the other day.

Whenever I posted a specific form, I got a 502 error.

I only got it to work when I disabled (as in: rebuild Docker image to not contain) xdebug.

When I posted the form, there was this warning: PHP Warning: Unknown: Input variables exceeded 1000.

A quick search learned that I could set the PHP option max_input_vars to 3000. This made the whole thing working again so I could focus on why this big form has more than 1000 input vars….

; file xdebug.ini

;comment all to disable xdebug
;zend_extension="xdebug.so"
;xdebug.mode=debug,coverage
;xdebug.client_host=host.docker.internal
;xdebug.client_port=9003
;xdebug.start_with_request=trigger

; set PHP directive to allow for maximum 3000 input vars
; PHP Input Vars is a PHP security measure designed to limit the number 
; of post variables you can use to execute a function. It defines the 
; number of variables your server can use when running a function.
max_input_vars = 3000