I'm currently trying to get nginx to add a header to the response when it is sending some kind of 50* error. I already have an add_header directive on the http block, and that gets respected for all requests except it seems errors. I also tried the following in one of my vhosts:
location /mediocregopheristhecoolest { add_header X-Test "blahblahblah"; return 502; } Going to that page gives me a 502, but no header. Is this simply something nginx doesn't do, or am I doing it wrong?
The documentation states that add_header "Adds the specified field to a response header provided that the response code equals 200, 204, 206, 301, 302, 303, 304, or 307. A value can contain variables." So it doesn't work with a 502.
I forgot to add that you can use the third party headers more module to add headers to other codes. You'll probably have to recompile to add it, though.
Since Nginx 1.7.5 you can use always to add a header irrespective of the response code:
add_header X-Test "blahblahblah" always; 