Certified Kubernetes Application Developer (CKAD) Study Guide, 2nd Edition

Chapter 11. Deployment Strategies

Deploying an application (bundled into a container image) to one or many Pods is only the beginning of its life cycle within a Kubernetes cluster. Periodically, developers will produce and publish new container image tags to ship bug fixes and new features. Manually updating Pods with a new container image tag one by one would be extremely tedious. Kubernetes offers the Deployment primitive to streamline the process.

Chapter 10 explained how to automatically roll out a new release using the Deployment primitive. In this chapter, we will discuss the built-in deployment strategies supported by the primitive. We’ll also talk about other deployment strategies that require deliberate human decisions. Each deployment strategy is presented with an example featuring their benefits and potential trade-offs. More deployment strategies exist, but they will not be covered in this book.

Note

Some deployment strategies require the use of concepts not yet discussed. Jump to Chapter 14 for coverage of container probes. Reference Chapter 21 for more information on the purpose of Services.

Coverage of Curriculum Objectives

This chapter addresses the following curriculum objective:

• Use Kubernetes primitives to implement common deployment strategies (e.g., blue/green or canary)

Rolling Deployment Strategy

The Deployment primitive employs rolling deployment as the default deployment strategy, also referred to as ramped deployment. It’s called “ramped” because ...