Create a web server on a compute instance https://docs.oracle.com/en/learn/lab_compute_instance/index.html#troubleshooting
firewall-cmd
https://firewalld.org/documentation/man-pages/firewall-cmd.html
sudo firewall-cmd –add-port=8000/tcp # don’t forget the equal
sudo firewall-cmd –reload
https://superuser.com/questions/1487012/no-route-to-host-when-trying-to-connect-to-a-tcp-service-on-an-oracle-cloud-in