The last layer of the Kubernetes system is the ecosystem, and it's by far the busiest and most hectic part of the picture. Kubernetes approach to container orchestration and management is to present the user with the options of a complementary choice; there are plug-in and general purpose APIs available for external systems to utilize. You can consider three types of ecosystem pieces in the Kubernetes system:

• Above Kubernetes: All of the glue software and infrastructure that's needed to "make things go" sits at this level, and includes operational ethos such as ChatOps and DevOps, logging and monitoring, Continuous Integration and Delivery, big data systems, and Functions as a Service.
• Inside Kubernetes: In short, what's inside a container is outside of Kubernetes. Kubernetes, or K8s, cares not at all what you run inside of a container.
• Below Kubernetes: These are the gray squares detailed at the bottom of the diagram. You'll need a technology for each piece of foundational technology to make Kubernetes function, and the ecosystem is where you get them. The cluster state store is probably the most famous example of an ecosystem component: etcd. Cluster bootstrapping tools such as minikube, bootkube, kops, kube-aws, and kubernetes-anywhere are other examples of community-provided ecosystem tools.

Let's move on to the architecture of the Kubernetes system, now that we understand the larger context.