oliverdavies.uk/source/_posts/nginx-redirects-query-string-arguments.md

title	date	excerpt	tags
Nginx Redirects With Query String Arguments	2017-01-31	How to redirect from an old domain to a new one, and also to redirect from the root example.com domain to the canonical www subdomain.	nginx

This is an example of how my Nginx configuration looked to redirect from an old domain to a new one, and also to redirect from the root example.com domain to the canonical www subdomain.

server {
  listen 80;

  server_name example.com;
  server_name my-old-domain.com;
  server_name www.my-old-domain.com;

  return 301 https://www.example.com$uri;
}

It also redirects the URI value, e.g. from http://example.com/test to http://example.com/test, but I noticed recently though that any the query string would be lost - e.g. http://example.com/?test would redirect to http://www.example.com and the ?test would be dropped. The application that I built references images based on the query string, so I wanted these to be included within the redirect.

This was fixed by making a small change to my return statement.

Before:

return 301 https://www.example.com$uri;

After:

return 301 https://www.example.com$uri$is_args$args;

$is_args is an empty string if there are no arguments, or a ? to signify the start of the query string. $args then adds the arguments ($query_string could also be used with the same result).

Here is an demo of it working on this website:

Resources

• Query string
• Nginx ngx_http_core_module