The pod concept is key to understanding Kubernetes. A pod is a group of containers that run together. It is very simple. All of these containers share a network namespace and storage. It is like a small logical host because we run many processes together, sharing the same IP addresses and volumes. The isolation methods that we learned about in Chapter 1, Modern Infrastructures and Applications with Docker, are applicable here.
Pods
Pods are the smallest scheduling unit in Kubernetes environments. Containers within a pod will share the same IP address and can find each other using localhost. Therefore, assigned ports must be unique within pods. We cannot reuse ports for other containers and inter-process communication because processes will run as if they were executed on the same logical host. A pod's life relies on the healthiness of a container.
Pods can be used to integrate full application stacks, but it is true that they are usually...