https://www.burndogfather.com/187
https://stackoverflow.com/questions/7947030/nginx-no-www-to-www-and-www-to-no-www
https://www.ucert.co.kr/wiki/w/Nginx_SSL_%EB%A6%AC%EB%8B%A4%EC%9D%B4%EB%A0%89%ED%8A%B8_%EC%84%A4%EC%A0%95
https://onecompiler.com/questions/3snpjw7ev/unable-to-run-spring-boot-on-80-port
polyglot