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

Motivation

Some companies are already trying to transition their services from traditional VMs in the cloud or other container orchestration tools (for example, AWS ECS, Azure CI, and so on) to K8s clusters. One of the biggest problems though in moving to K8s is how we can set up more sophisticated deployment strategies, as the standard rolling updates provided for free by K8s would not work in some cases. For example, what if I want to deploy a new version of a service but I want to first test that it’s functional and then switch to the new version and, in parallel, destroy the old one? This is called blue/green deployment and can give me the power to reduce downtime and not even impact my end users.

In the next section, we will see how we can achieve this in K8s using only the K8s objects and how we can deploy a service with blue/green deployment.

Simple blue-green in K8s

I have created a small Golang app that serves a simple HTTP server and returns the version of...