Kubernetes Best Practices

Chapter 13. Integrating External Services and Kubernetes

In many of the chapters in this book, we’ve discussed how to build, deploy, and manage services in Kubernetes. However, the truth is that systems don’t exist in a vaccum, and most of the services that we build will need to interact with systems and services that exist outside of the Kubernetes cluster in which they’re running. This might be because we are building new services that are being accessed by legacy infrastructure running in virtual or physical machines. Conversely, it might be because the services that we are building might need to access preexisting databases or other services that are likewise running on physical infrastructure in an on-premises datacenter. Finally, you might have multiple different Kubernetes clusters with services that you need to interconnect. For all of these reasons, the ability to expose, share, and build services that span the boundary of your Kubernetes cluster is an important part of building real-world applications.

Importing Services into Kubernetes

The most common pattern for connecting Kubernetes with external services consists of a Kubernetes service that is consuming a service that exists outside of the Kubernetes cluster. Often, this is because Kubernetes is being used for some new application development or interface for a legacy resource like an on-premises database. This pattern often makes the most sense for incremental development of cloud-native services. Because the ...