Hello,

nginx 1.12 grew its own $request_id variable [1] which means that the x-rid header module doesn't work anymore. When the module is compiled into 1.12 nginx fails to start with the following error:

    nginx: [emerg] the duplicate "request_id" variable in /usr/local/etc/nginx/nginx.conf:16

where line 16 is where the http {} section starts. This happens even with an empty http {} section.

This can be a nasty surprise if upgrading nginx on a server and it refuses to start no matter what you do.

Since nginx now has it's own $request_id variable which does the same thing more or less, I suggest just removing the XRID_HEADER option and module. Servers which use $request_id in logs or other places will keep working, although the unique request id looks different:

$request_id under nginx 1.10 with XRID_HEADER option: b14cb555-2c7a-11e7-9c03-0cc47a500f28
$request_id under nginx 1.12 without XRID_HEADER option: 416e2ca685b484a7c7218e24e3e98d4b

Alternatively we would have to get upstream to change the name of the request id variable in the 3rd party module at [2]. Once that is done we would have to warn all users to rename the variable in their configs.


Best regards

/Thomas

[1]: https://github.com/nginx/nginx/commit/f315b7a924fa2c0da69c21078c930391a424aeef
[2]: https://github.com/gabor/nginx-x-rid-header/blob/master/ngx_x_rid_header_module.c#L84