Controlling egress traffic from pods using firewalld

Issue

• One of the methods to control egress traffic from pods according to OpenShift Container Platform documentation is iptables.
• Egress firewall and/or router are scoped to a single project while iptables rules are global to all projects.
• Using firewalld allows to add/remove rules dinamically without restarting OpenShift services. Also, while iptables is the default firewall, firewalld is recommended for new installations.