httpupdate.cpanel.net did not have any working mirrors

Symptoms

The following error can happen on your system when your cPanel and WHM server is having difficulty creating outbound connections:

Requesting script ... httpupdate.cpanel.net did not have any working 
mirrors. Please check your internet connection or dns server
at /usr/local/cpanel/Cpanel/HttpRequest.pm line 921.

Description 

This problem can show up when working with Yum, cPanel automated updates that run overnight, or when trying to add features to the system through the EasyApache 4 interface.  If the server isn't able to make outbound connections, it won't be able to contact the mirrors to download those updates.

Workaround

The best thing to do in this situation is to make sure that all the necessary ports are open for traffic on the system. Using the command-line tool "telnet" on your server will display results similar to the following:

telnet httpupdate.cpanel.net 80

[root@server ~]cPs# telnet httpupdate.cpanel.net 80
Trying 208.43.129.162...
Connected to httpupdate.cpanel.net.
Escape character is '^]'.

If your server does not have the "telnet" command available, you can use the "netcat" command like this instead:

nc -v httpupdate.cpanel.net 80

[root@server ~]cPs# nc -v httpupdate.cpanel.net 80
Ncat: Version 7.70 ( https://nmap.org/ncat )
Ncat: Connected to 208.43.129.162:80.

Additional Resources:

We have a guide that explains what ports need to be open in order for a cPanel system to function, so checking your server settings against the details in that guide will help to resolve this issue:

How to Configure Your Firewall for cPanel & WHM Services