Keeping Kubernetes deployments consistent across dozens of clusters is hard when changes are applied by hand. ArgoCD solves this by treating Git as the single source of truth for what should be running, then continuously reconciling the live cluster state to match it.
What Is ArgoCD?
ArgoCD is a declarative, GitOps continuous delivery tool built specifically for Kubernetes. Instead of pushing changes to a cluster through a CI pipeline, ArgoCD pulls the desired state from a Git repository and automatically applies it, then keeps watching for drift so the cluster never silently diverges from what’s committed.
Why Teams Choose GitOps
Manually running kubectl apply from a laptop makes it hard to know who changed what, and rollbacks mean digging through shell history. GitOps fixes this by making every change a pull request, so you get a full audit trail, easy rollbacks via git revert, and a clear separation between what’s declared and what’s actually running.
- Every change is version-controlled and reviewable before it ships
- Rollbacks are just a git revert, not a scramble to remember the last good state
- Multiple clusters can be kept in sync from the same repository
- Drift between the repo and the live cluster is detected automatically
How ArgoCD Works
ArgoCD runs as a controller inside your cluster and continuously compares the manifests in a connected Git repository against the live objects in Kubernetes. When it finds a difference, it marks the application as OutOfSync, and depending on your settings, either alerts you or heals the drift automatically by reapplying the desired state.
Installing ArgoCD on Your Cluster
Getting a working instance running takes just a couple of commands. Create a dedicated namespace, apply the official installation manifest, then use the CLI or UI to log in and start connecting repositories.
kubectl create namespace argocd
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml
Defining Your First Application
An ArgoCD Application is itself a Kubernetes custom resource that points at a Git repository path and a destination cluster and namespace. Once it’s created, ArgoCD takes over, pulling manifests from that path and syncing them to the target automatically whenever the repository changes.
Best Practices for Production GitOps
- Keep application manifests in a dedicated repository, separate from application source code
- Use separate branches or directories per environment instead of separate clusters’ worth of copy-pasted YAML
- Turn on automated sync and self-healing only after you trust your manifests, and always enable pruning carefully
- Store secrets outside of Git using a tool like Sealed Secrets or an external secrets operator
Final Thoughts
ArgoCD doesn’t replace your CI pipeline, it picks up where CI leaves off, turning “the build passed” into “the cluster now matches Git.” For teams running more than a handful of services across multiple environments, that shift from manual deployment to continuous reconciliation is often the difference between confident releases and late-night firefighting.