Deployment strategies affect everyone, no matter whether we are focused only on a single aspect of the application lifecycle or we are in full control. The way we deploy affects the architecture, testing, monitoring, and many other aspects. And not only that, but we can say that architecture, testing, and monitoring affect the way we deploy. All those things are closely related and affect each other.
We'll discuss different deployment strategies and answer a couple of questions. Is your application stateful or stateless? Does its architecture permit scaling? How do you roll back? How do you scale up and down? Do you need your application to run always? Should you use Kubernetes Deployments instead of, let's say, StatefulSets? Answers to those questions will not serve much unless we are familiar with some of the most commonly used deployment strategies. Not only that knowledge will help us choose which one to pick, but they might even influence the architecture of our applications.
This time I will not write a lenghtly post. Instead, I'll try to explain different deployment strategies through diagrams. This is for all those who dislike black and white terminal and prefer colors, boxes, and lines with arrows.
The deployment strategies are not presented in any particular order.
Serverless deployments are gaining traction. Today, we have quite a few choices for converting our applications into serverless inside Kubernetes cluster. One of those, my favorite, is Knative. We'll explore how we can combine it with Jenkins X to create a fully automated continuous deployment pipeline that deploys serverless applications.
The serverless flavor of Jenkins X or, as some call it, Jenkins X Next Generation, is an attempt to redefine how we do continuous delivery and GitOps inside Kubernetes clusters. It does that by combining quite a few tools into a single easy-to-use bundle. As a result, most people will not have a need to understand intricacies of how the pieces work independently, nor how they are all integrated. Instead, many will merely push a change to Git and let the system do the rest. But, there are always those who would like to know what's happening behind the hood. To satisfy those craving for insight, we'll explore the processes and the components involved in the serverless Jenkins X platform. Understanding the flow of an event initiated by a Git webhook will give us insight into how the solution works and help us later on when we go deeper into each of the new components.