Certain questions about Kubernetes seem to come up again and again: What’s up with this init container stuff? What’s a CNI plugin? Why is Kubernetes complaining about pods not finishing initialisation? Kubernetes is a complex system with a simple overall purpose: run user workloads in a way that permits the authors of the workloads to not care (much) about the messy details of the hardware underneath. The workload authors are supposed to be able to just focus on Pods and Services; in turn, Kubernetes is meant to arrange things such that workloads get mapped to Pods, Pods get deployed on Nodes, and the network in between looks flat and transparent. This is simple to state, but extremely complex to implement in practice. (This is an area where Kubernetes is doing a great job of making things complex for the Kubernetes implementors so that they can be easier for the users – nicely done!) Under the hood, Kubernetes is leaning heavily on a number of technologies to make all this happen.