What is Argo CD and why should you stop using kubectl apply manually?

Tired of writing kubectl get pods or kubectl delete pod? Argo CD is a tool that revolutionizes Kubernetes deployment. It lets you instantly see everything deployed on Kubernetes and whether it’s synchronized with your code repository, following the GitOps philosophy.

How does Argo CD work?

Argo CD connects to a Git repository and deploys the resources defined for the different configured clusters.

This keeps your Kubernetes environment aligned with the desired state stored in Git, avoiding manual changes and potential human errors. Using Argo CD is, in many ways, a guarantee of quality and safety, since it eliminates several failure points. And if that’s not convincing enough, here are some of the main benefits of Argo CD.

Benefits of Argo CD

• Centralizes all deployments, allowing you to review the configuration through its interface—reducing cognitive load and simplifying how you understand the entire deployment process.
• Allows deployment to multiple clusters, including powerful features such as App-of-Apps, auto-discovery, and policies.
• Supports deployment of various CRDs (Custom Resource Definitions): kustomize, helm, ksonnet, jsonnet, and traditional YAML files.
• Provides a role-based security model, enabling Argo CD roles to be mapped to your SSO roles.
• Accessible through both UI and CLI.

These are only some of the benefits. To fully understand Argo CD, we need to look into its basic concepts.

Basic concepts

Some of the basic concepts you’ll find in the Argo CD admin console include:

• Application: the definition of the app you want to deploy, including repository, project, and target cluster.
• Project: a logical grouping of applications. Especially useful when multiple teams operate in Argo CD to avoid mistakes.
• Sync: the process through which changes are applied to align the application with its desired state. The UI also shows details about the sync status (success, timestamp, author, comments).
• Refresh: compares the latest committed code in Git with the live state, showing differences at a glance.
• Health: indicates the application's status—Is it running correctly? Can it handle requests?

As a picture is worth a thousand words, here’s a screenshot showing the key parameters:

Graphical Interface

One of the greatest strengths of Argo CD is its UI: intuitive, clean, and filled with useful information for operators and teams.

The UI lets you sync applications—goodbye kubectl apply! And if no one is watching, you can even live-edit a file (I won’t judge). The good thing is that Argo CD won’t let it slip—it will remind you that the application is out of sync with Git.

Autosync, prune and autohealing

Let’s say you want to prevent someone from modifying files directly in production. Can Argo CD help? Absolutely! Argo CD offers several synchronization modes:

• Automated self-healing: when enabled, the live state will always match Git. Any manual change to resources will be automatically reverted.
• Automated sync: Argo CD checks repositories every 3 minutes. If changes are detected and auto sync is enabled, they’ll be deployed automatically.
• Automated pruning: automatically removes resources that are no longer defined in Git—saving you time and headaches.

Sync Windows

As we've seen, Argo CD is an extremely complete tool, right? But there’s more! Argo CD allows multiple configuration types based on your needs. Here are a few examples:

• Define sync windows for applications.
• Allow or deny synchronization depending on project rules.
• Enable manual sync.

Conclusion

Argo CD helps you automate, audit, and simplify the lifecycle of your Kubernetes deployments. Less kubectl, more control, more security. Ready to try it out? Let me know in the comments! 😉