#Starting iwth docker and kubernetes install
#Starting iwth docker and kubernetes manual
#Starting iwth docker and kubernetes upgrade

#Starting iwth docker and kubernetes install

Since a while, Docker Desktop also comes with built-in support for Kubernetes, meaning that you don't have to install anything special to spin a Kubernetes cluster on your machine. Thanks to this application, we can install on our machine everything we need to play with Docker containers. If you have already followed the previous posts about Docker, you should already have on your machine Docker for Windows, which has been recently rebranded as Docker Desktop. However, for the moment, we will play with Kubernetes on our local machine, which is the easiest way to understand how it works at no costs. Of course, also Microsoft Azure offers its own service, called Azure Kubernetes Service (AKS, in short).

This is why all the major cloud providers offers a dedicated PaaS (Platform-As-A-Service) offer for Kubernetes, where you don't have to worry about the underlying infrastructure. Kubernetes, in fact, shines when it's used in a cloud architecture, where it has the chance to quickly spin up all the required resoruces to maintain the desired state or to scale in case of high traffic. In the real world, you will hardly have to setup a Kubernetes infrastructure on your own. I'm a tech enthusiast who likes to play with technology and I've tried to put in words how I ramped up on it and what I've learned in the process, hoping that it can be useful also for you! Creating a Kubernetes playground In this post we're going to see how we can leverage Kubernetes to manage the web application we have built in the previous posts.Р”Вisclaimer!Р’В I'm not a Kubernetes guru, so don't expect to become a super Kubernetes expert after reading this post. For example, if you have specified that you always need at minimum 5 instances of the frontend up & running and one of them fails, the orchestrator will take care of spinning up a new instance to replace the failing one. Then the orchestrator will take care of keeping the state of the application consistent with the definition. Typically, you feed an orchestrator with the definition of the default state for your application: which are the layers that compose it, how many instances of each layer you need, how much CPU each layer can consume, etc. Exactly like the director of an orchestra make sure that everyone is playing in the right way, Kubernetes 'orchestrates' our solution to make sure everything is running in the desired state. It's what we call 'an orchestrator' and it's an open source project created by Google which has quickly become another standard in the industry. We are using containers and the power of the cloud so that we don't have to worry anymore about these kind of issues, so having to manually react to events kills our great story. As you can imagine, this isn't an ideal approach. Or in case of heavy traffic, we need to manually add new containers to scale out our application. If something goes wrong with one of the containers, we need to manually take it down and spin up a new one.

#Starting iwth docker and kubernetes manual

However, this solution still requires manual management from our side. This way, we can be sure that no matter where we're going to deploy our solution, it will always work as exepected and with the desired configuration. Additionally, thanks to Docker, we can encapsulate inside the container not only the application but also its configuration (frameworks, dependencies, etc.).

#Starting iwth docker and kubernetes upgrade

Thanks to Docker, we were easily able to deploy all the layers at the same time in different containers and to maintain, scale and upgrade them separately. In our case, we took a 3 tier application (frontend, backend and cache) and we packaged it into three different containers. Why? In the previous posts we have learned how Docker is a great solution to turn your multi-tier application into multiple containers, so that they can be easily deployed and maintained independently. Nowadays it's hard to not seeing Docker mentioned together with Kubernetes. Additionally, we're going to leverage the same web application we have built in the upcoming samples. I strongly suggest you to read these articles before moving on with this one because I will consider many of the concepts I've already explained as granted.

Here is a recap of the topics we have seen so far: Docker is the standard de-facto solution in the market for containerazing applications, so that you can easily move them to a modern and cloud world. I already had the chance to talk about Docker in this blog.