Nginx auth with login-form passthrough

nginx_auth1.conf

# This variant uses the same endpoint for the check and the login form
server {
	listen 80;
	server_name localhost;
	
	location = /internal-nginx-auth-endpoint {
		internal;
		proxy_pass http://172.17.0.1:8080/;
	}

	error_page 401 = /internal-nginx-auth-endpoint;
	location / {
		auth_request /internal-nginx-auth-endpoint;
	}
}

nginx_auth2.conf

# This variant uses the a minimal endpoint for the check and a different one for the login form
server {
	listen 80;
	server_name localhost;
	
	location = /internal-nginx-auth-login-endpoint {
		internal;
		proxy_pass http://172.17.0.1:8080/login;
	}
	location = /internal-nginx-auth-check-endpoint {
		internal;
		proxy_pass http://172.17.0.1:8080/check;
		proxy_pass_request_body off;
		proxy_set_header Content-Length "";
	}

	error_page 401 = /internal-nginx-auth-login-endpoint;
	location / {
		auth_request /internal-nginx-auth-check-endpoint;
	}
}