Book Image

Argo CD in Practice

By : Liviu Costea, Spiros Economakis
Book Image

Argo CD in Practice

By: Liviu Costea, Spiros Economakis

Overview of this book

GitOps follows the practices of infrastructure as code (IaC), allowing developers to use their day-to-day tools and practices such as source control and pull requests to manage apps. With this book, you’ll understand how to apply GitOps bootstrap clusters in a repeatable manner, build CD pipelines for cloud-native apps running on Kubernetes, and minimize the failure of deployments. You’ll start by installing Argo CD in a cluster, setting up user access using single sign-on, performing declarative configuration changes, and enabling observability and disaster recovery. Once you have a production-ready setup of Argo CD, you’ll explore how CD pipelines can be built using the pull method, how that increases security, and how the reconciliation process occurs when multi-cluster scenarios are involved. Next, you’ll go through the common troubleshooting scenarios, from installation to day-to-day operations, and learn how performance can be improved. Later, you’ll explore the tools that can be used to parse the YAML you write for deploying apps. You can then check if it is valid for new versions of Kubernetes, verify if it has any security or compliance misconfigurations, and that it follows the best practices for cloud-native apps running on Kubernetes. By the end of this book, you’ll be able to build a real-world CD pipeline using Argo CD.
Table of Contents (15 chapters)
1
Part 1: The Fundamentals of GitOps and Argo CD
4
Part 2: Argo CD as a Site Reliability Engineer
7
Part 3: Argo CD in Production

Validating a Kubernetes schema

New Kubernetes versions can come with API version deprecations and removals. For example, in release 1.16 for CustomResourceDefinition, the apiextensions.k8s.io/v1 version was introduced, while in apiextensions.k8s.io/v1beta1 it was deprecated, and later, in version 1.22, it was completely removed. So, if you used apiextensions.k8s.io/v1beta1 for CustomResourceDefinitions starting with Kubernetes version 1.16, you would get a deprecation warning, while if you used it with version 1.22, you would get an error because the version doesn’t exist anymore.

Usually, the problem is not only about applying older and unsupported API versions to a Kubernetes cluster; instead, it may be more likely that you have a deprecated version already installed with some applications, after which you upgrade the cluster to a version where the API is completely removed. Normally, you should catch it while you upgrade the development or testing clusters, but there is...