Summary

In this chapter, we learned how containers communicate with each other. We also introduced how pod-to-pod communication works. A service is an abstraction that routes traffic to any of the pods underneath it if the label selectors match. We also learned how a service works with a pod using iptables. We also familiarized ourselves with how packet routes from external services to a pod using DNAT and un-DAT packets. In addition to this, we looked at new API objects such as ingress, which allows us to use the URL path to route to different services in the backend. In the end, another NetworkPolicy object was introduced. This provides a second layer of security, and acts as a software firewall rule. With the network policy, we can make certain pods communicate with certain other pods. For example, only data retrieval services can talk to the database container. In the last...