Nginx Loses Port on Redirect

Solution 1:

The default proxy_redirect when using a proxy_pass inside a location (adapted to your use case) is:

location / {
  proxy_pass     http://localhost:8080/;
  proxy_redirect http://localhost:8080/ /;
}

Since you are using the same 8080 port in Vagrant, this will match and remove the port.

There are two easy solutions to avoid this:

1. Forward to a different port in the vagrant configuration so that proxy_redirect doesn't match.
2. Disable proxy_redirect using proxy_redirect off;.

(I know this was 4 years ago, but I just had a similar problem while testing KeyCloak, so I hope this answer helps others that face this problem.)