In the previous section, we gained a first impression of the core Kubernetes components: etcd, the API server, the scheduler, the controller manager, and the kubelet. These components, plus other add-ons, comprise the Kubernetes architecture, which can be seen in the following diagram:
Figure 2.8: Kubernetes architecture
At this point, we won't look at each component in too much detail. However, at a high-level view, it's critical to understand how the components communicate with each other and why they're designed in that way.
The first thing to understand is which components the API server can interact with. From the preceding diagram, we can easily tell that the API server can talk to almost every other component (except the container runtime, which is handled by the kubelet) and that it also serves to interact with end-users directly. This design makes the API server act as the "heart" of Kubernetes. Additionally...