This post describes how you can unblock port 80 to allow HTTP traffic through in the Fedora firewall.
Unblocking port 80 so HTTP traffic can reach a webserver
By default Fedora 27 has a firewall which blocks traffic reaching port 80.
To disable this permanently and reload the firewall configuration so it’s immediately available you can run the following command.
sudo firewall-cmd --zone=public --permanent --add-service=http
sudo systemctl restart firewalld.service
This adds an exception for the HTTP service and unblocks port 80 on a permanent basis.
Hopefully this helps ensure your webserver is accessible from the outside world.