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

Wrap up

When Argo CD started back in 2018, nobody could have predicted its success. It had a good foundation (the Application CRD with its source, the Git repository where the manifests are located, and the destination, which is the cluster and namespace where deployments are performed), was well received, understood, and a good fit for the whole GitOps concept.

It also had the right context. Back then, as now, Helm was the most used application deployment tool for Kubernetes, and it was in the V2 version. This meant it came with a component called Tiller installed on the cluster (https://helm.sh/docs/faq/changes_since_helm2/#removal-of-tiller), which was used to apply the manifests, and that component was seen as a big security hole. With Argo CD, you could have still used Helm charts, but you didn’t need Tiller to perform the installation as manifests were generated and applied to the destination cluster by a central Argo CD installation. I remember back then we saw this...