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

Planning for disaster recovery

Argo CD doesn’t use any database directly (Redis is used as a cache), so it looks like it doesn’t have any state. Earlier, we saw how we can have a high availability installation, done mostly by increasing the number of replicas for each deployment. But we also have application definitions (such as the Git source and destination cluster) and details on how to access a Kubernetes cluster or how to connect to a private Git repo or a private Helm one. These things, which make up the state of Argo CD, are kept in Kubernetes resources – either native ones, such as secrets for connection details, or custom ones for applications and application constraints.

A disaster may occur due to human intervention, such as the Kubernetes cluster or the Argo CD namespace being deleted, or maybe some cloud provider issues. We may also have scenarios where we want to move the Argo CD installation from one cluster to another. For example, maybe the...