Argo CD

Argo CD is a Kubernetes native continuous delivery tool that uses GitOps principles to manage and deploy applications. It continuously monitors application definitions stored in Git repositories and ensures that the running state in Kubernetes matches the desired state defined in Git.

Purpose

Argo CD is designed to automate application deployment, configuration management, and lifecycle operations in Kubernetes environments. It provides visibility, consistency, and control over deployments by treating Git as the single source of truth.

How It Works in Simple Terms

You describe how your application should run and save that description in Git, which is like a shared notebook everyone agrees to follow. Argo CD constantly checks your system and compares it to that notebook. If it sees something different, it can either alert you or automatically correct it.

Key Concepts

GitOps
Argo CD follows the GitOps model, where all application configurations are stored in Git. Any change to Git is automatically detected and applied to the cluster.

Desired State
The configuration defined in Git represents the desired state of an application. Argo CD compares this with the live state running in Kubernetes.

Live State
The actual state of resources currently running in the Kubernetes cluster.

Synchronization
The process by which Argo CD reconciles differences between the desired state in Git and the live state in the cluster. Synchronization can be automatic or manual.

Drift Detection
Argo CD continuously detects configuration drift when changes occur directly in the cluster that are not reflected in Git.

Common Use Cases

Managing Kubernetes application deployments
Enforcing configuration consistency across environments
Auditing and tracking infrastructure changes
Supporting continuous delivery pipelines
Reducing manual deployment errors