auth/reverseproxy: Add support for full name (#20776)

This adds support for getting the user's full name from the reverse
proxy in addition to username and email.

Tested locally with caddy serving as reverse proxy with Tailscale
authentication.

Signed-off-by: Will Norris <will@tailscale.com>

Signed-off-by: Will Norris <will@tailscale.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

services/auth/reverseproxy.go

@@ -105,9 +105,15 @@ func (r *ReverseProxy) newUser(req *http.Request) *user_model.User {
 		}
 	}
 
+	var fullname string
+	if setting.Service.EnableReverseProxyFullName {
+		fullname = req.Header.Get(setting.ReverseProxyAuthFullName)
+	}
+
 	user := &user_model.User{
-		Name:  username,
-		Email: email,
+		Name:     username,
+		Email:    email,
+		FullName: fullname,
 	}
 
 	overwriteDefault := user_model.CreateUserOverwriteOptions{