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Your First Synced App

Argo CD is running. Your manifests are in Git. Now you connect the two: you tell Argo CD to watch your repository, and it deploys Snapshot into the cluster for you. This is your first real GitOps deployment. 🎉

What we will do (in very simple steps)

  1. Understand what an Argo CD Application is
  2. Point Argo CD at your repository
  3. Sync it, and watch Snapshot appear

What an Application is

In Argo CD, an Application is a small definition that says: watch this folder, in this repository, and keep this cluster namespace matching it. Once it exists, Argo CD takes over the deploying.

Step 1: Create the Application

In the Argo CD dashboard, click New App, then fill in:

  • Application Name: snapshot
  • Project: default
  • Sync Policy: Manual (we will sync by hand this first time)
  • Repository URL: https://github.com/YOUR_USERNAME/snapshot-app.git
  • Revision: HEAD
  • Path: k8s
  • Cluster URL: https://kubernetes.default.svc (the in-cluster option)
  • Namespace: default

Click Create.

Your app appears on the dashboard, marked OutOfSync. That means Argo CD can see what Git wants, but has not applied it yet.

Step 2: Sync it

Click into the snapshot app, then click Sync, then Synchronize.

Watch the diagram come to life. Argo CD reads your k8s/ folder and creates the Deployment and the Service. Within moments the app turns Synced and Healthy, and you can see the two Snapshot pods appear as boxes on the screen. You did not run a single kubectl apply. Argo CD did it, from Git. ✨

Step 3: Verify from the terminal

kubectl get pods
kubectl get svc

You will see two snapshot pods running and the snapshot service. To reach the app, forward its port:

kubectl port-forward svc/snapshot 8000:80

Open http://localhost:8000 and there is Snapshot, deployed by GitOps.

The more GitOps way

You created the Application through the dashboard, which is great for learning. In a full GitOps setup, the Application itself is a manifest committed to Git, so even Argo CD's configuration is version-controlled:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: snapshot
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/YOUR_USERNAME/snapshot-app.git
    targetRevision: HEAD
    path: k8s
  destination:
    server: https://kubernetes.default.svc
    namespace: default

You would apply this once, and from then on everything lives in Git. Keep it in mind, we build on it next.

✅ Checkpoint

You are ready for the next lesson if:

  • You created a snapshot Application in Argo CD
  • Syncing it deployed the Deployment and Service
  • The app shows Synced and Healthy, and you reached Snapshot in the browser

🩹 Common hiccups

  • "repository not accessible": the repo URL must be correct, and the repo public (or Argo CD given credentials).
  • Stuck OutOfSync after syncing: open the app and read the message on the failing resource. A bad image tag or a manifest typo is the usual cause.
  • Pods not starting: check the image in deployment.yaml exists and is public. Argo CD deploys it, but the cluster still has to pull it.

Next up: Closing the Loop, where a new image from CI flows all the way to the cluster automatically.