How to check substring using regular expression in Nginx config? - nginx

Question

I try to check some parameters in request. Here is my url:
http://localhost:8080/wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&LAYERS=004C0000064F&
STYLES=&WIDTH=256&HEIGHT=256&FORMAT=image%2fjpeg&CRS=EPSG%3a100000&DPI=96&
MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi%3a96&
BBOX=1530569.52624839870259166%2c524135.21126760687911883%2c1531064.27656850102357566%2c524629.96158770937472582
I trying to get REQUEST parameter. Here is my nginx 1.12.1 config:
server {
listen 8080;
server_name 127.0.0.1 localhost;
set $site_backend localhost:56297;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
location /favicon.ico {
error_page 403 404 = #tomcat_static_mapping;
}
location ~* /wms {
internal;
add_header URI $request_uri;
add_header X-debug-message1 "$request_uri" always;
if ($request_uri ~* REQUEST=([^&]*)) {
add_header X-debug-message2 "hi" always;
set $requesttype $1;
}
}
}
And in browser i got header:
X-debug-message1: /wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&LAYERS=004C0000064F&STYLES=&WIDTH=256&HEIGHT=256&FORMAT=image%2fjpeg&CRS=EPSG%3a100000&DPI=96&MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi%3a96&BBOX=1530569.52624839870259166%2c524135.21126760687911883%2c1531064.27656850102357566%2c524629.96158770937472582
But not get X-debug-message2 header. I check regular expression here https://rubular.com/ and it's found match and return GetMap as like i want.
What can be wrong here?

Answer 1

Something is not complete / matching in your post. I got X-debug-message2: hi only which does match to how nginx has to behave:
These directives are inherited from the previous level if and only if there are no add_header directives defined on the current level
For more intuitive outcome, use Headers-More module.
more_set_headers "URI: $request_uri";
more_set_headers 'X-debug-message1: "$request_uri"';
location ~* /wms {
if ($request_uri ~* REQUEST=([^&]*)) {
more_set_headers 'X-debug-message2: hi';
set $requesttype $1;
}
}