Kubernetes Patterns, 2nd Edition

Afterword

Kubernetes is the leading platform for deploying and managing containerized distributed applications at scale. However, these on-cluster applications rely on off-cluster resources, including databases, document stores, message queues, and other cloud services. Kubernetes is not limited to managing applications within a single cluster. Kubernetes can also orchestrate off-cluster resources through various cloud services’ operators. This allows Kubernetes APIs to be the single “source of truth” for a resource’s desired state, not only for on-cluster containers but also for off-cluster resources. If you are already familiar with Kubernetes patterns and practices for operating applications, you can leverage this knowledge for managing and using external resources too.

The physical boundaries of a Kubernetes cluster don’t always conform to the desired application boundaries. Organizations often need to deploy applications across multiple data centers, clouds, and Kubernetes clusters for a variety of reasons, such as scaling, data locality, isolation, and more. Often, the same application or a fleet of applications has to be deployed into multiple clusters, which requires multicluster deployments and orchestration. Kubernetes is frequently embedded in various third-party services and used for operating applications across multiple clusters. These services utilize the Kubernetes API as the control plane, with each cluster serving as a data plane, allowing Kubernetes to extend ...