PART V Advanced Patterns The patterns in this category cover more complex topics that do not fit in any of the other categories. Some of the patterns here such as  Controller  are timeless, and Kuber‐ netes itself is built on them. However, some of the other pattern implementations are still very new (like Knative for building container images and scale-to-zero for Serv‐ ices) and might already be different by the time you read this book. To keep up with this, we will keep our online examples up-to-date and reflect the latest developments in this space. In the following chapters, we explore these advanced patterns: • Chapter 22,  Controller , is essential to Kubernetes itself and this pattern shows how custom controllers can extend the platform. • Chapter 23,  Operator , combines a  Controller  with custom and domain-specific resources to encapsulate operational knowledge in an automated form. • Chapter 24,  Elastic Scale , describes how Kubernetes can handle dynamic loads by scaling in various dimensions. • Chapter 25,  Image Builder , moves the aspect of building application images into the cluster itself.