ec2 생성 후 서버 연결 안됨 ? 참고) https://somjang.tistory.com/entry/AWS-Amazon-Linux-2-AMI-%EC%97%90%EC%84%9C-apt-get-%EC%9D%B4-%EC%8B%A4%ED%96%89%EB%90%98%EC%A7%80-%EC%95%8A%EC%9D%84-%EA%B2%BD%EC%9A%B0 참고) https://bobbyhadz.com/blog/aws-ec2-apt-get-command-not-found
