Spring get actual scheme from reverse proxy - spring

Question

I have a Spring Boot Web application running on Widlfly server. I implemented Facebook OAuth login by generate a button "Login With Facebook" linked to Facebook login endpoint.
https://www.facebook.com/v2.5/dialog/oauth?client_id=****&response_type=code&redirect_uri=http://example.com/login/facebook
I generate the value of redirect_uri using following java code.
public static String getFacebookRedirectUrl() {
RequestAttributes attrs = RequestContextHolder.getRequestAttributes();
if (attrs instanceof ServletRequestAttributes) {
HttpServletRequest request = ((ServletRequestAttributes) attrs).getRequest();
return request.getScheme() + "://"
+ request.getServerName() + ":"
+ request.getServerPort()
+ request.getContextPath()
+ "/login/facebook";
} else {
throw new RuntimeException("Cannot determine facebook oauth redirect url");
}
}
My website is deployed internally to http://my-ip-address:8080 and have a reversed proxy (nginx) forwarding requests from https://example.com to http://my-ip-address:8080.
The problem is the redirect-uri is always generated as http://example.com/login/facebook instead of https://example.com/login/facebook (not https).
Please help suggest how make request.getScheme() returns https correctly when the user access the website via https. Following is the reverse proxy configuration /etc/nginx/sites-enalbed/mysite.com
server {
listen 80;
listen 443;
server_name example.com www.example.com;
ssl on;
ssl_certificate /etc/nginx/cert.crt;
ssl_certificate_key /etc/nginx/cert.key;
location / {
proxy_pass http://my-ip-address:8080;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
}
}

Answer 1

request.getScheme() will always be http because you are proxying via http, but you are passing the request scheme in a header, so use that.
Change return request.getScheme() + "://" to return request.getHeader('X-Forwarded-Proto') + "://"
Not sure how java interprets headers, so X-Forwarded-Proto might become X_Forwarded_Proto or xForwardedProto or something else, but you get the idea...