As you have learned previously, routers in OpenShift direct ingress traffic from external clients to services that, in turn, forward it to pods. OpenShift also offers a reverse type of router intended for forwarding egress traffic from pods to a certain destination in the external network. But unlike ingress routers implemented via HAProxy, egress ones are built on Squid. Egress routers are potentially useful for cases such as:
- Masking different external resources being used by several applications with a single global resource. For example, applications may be developed in such a way that they are built pulling dependencies from different mirrors, and collaboration between their development teams is rather loose. So, instead of getting them to use the same mirror, an operations team can just set up an egress router to intercept all traffic directed to those mirrors...