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.
The video below is a clip from the "Canary Deployments To Kubernetes Using Istio and Friends" course in Udemy. It provides a high-level explanation how service mesh works. Additional preview clips are available inside the course. Please use the coupons with discounts provided below.
If you do enrol into the course, please let us know what you think and do NOT forget to rate it.
The video below is a clip from the "Canary Deployments To Kubernetes Using Istio and Friends" course in Udemy. It provides the introduction to the course we released in December 2019. Additional preview clips are available inside the course. Please use the coupons with discounts provided below.
If you do enrol into the course, please let us know what you think and do NOT forget to rate it.
Welcome to practical guide to canary deployments. Unlike some other work that I did…tutorials, workshops, and so on and so forth, that were very focused on a single tool, this time I will focus more on a process.
We’re going to try to figure out how to do canary deployments inside of Kubernetes. Because Kubernetes is everywhere now, I will assume that you are using Kubernetes. But outside of that, we are going to try to figure out which tools to use, but all serving as the process itself, not for the sake of learning a specific tool. And during that process, we are going to decide which tools to use and why to use them and the end result will be a fully operational canary deployments process that you will be able to plug into any CI/CD tool or any tool that orchestrates the lifecycle of your application.
So we will definitely choose some tools that we will use in a process.
And those tools will be revolving around Istio. I will explain why Istio a bit later.
So we will use Kubernetes and Istio for canary deployments, but the end result will be agnostic to the tool that will orchestrate your processes. We will most likely also have to choose one or two additional tools. Which tools we’ll choose is yet to be discovered.
For now just think of this as being a practical guide to a specific process. And that process today is canary deployments in Kubernetes.
A while ago, we (Viktor Farcic and Darin Pope) thought it would be a good idea to add an out-of-the-box option to use canary deployments in Jenkins X. We should have finished it by now, and yet we did not even start working on it. Instead of just adding it to Jenkins X, we spent considerable time exploring the subject.
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.
I am continuously getting questions about blue-green releases inside a Docker Swarm cluster. Viktor, in your The DevOps 2.0 Toolkit book you told us to use blue-green deployment. How do we do it with services running inside a Swarm cluster? My answer is usually something along the following lines. With the old Swarm, blue-green releases were easier than rolling updates (neither were supported out of the box). Now we got rolling updates. Use them! The reaction to that is often that we still want blue-green releases.
This post is my brainstorming on this subject. I did not write it as a result of some deep thinking. There is no great wisdom in it. I just wrote what was passing through my mind while I was trying to answer another one of the emails containing blue-green deployment questions. What follows might not make much sense. Don’t be harsh on me. Continue reading →