GitOps Principles and Implementation

Question

What is GitOps and how does it differ from traditional CI/CD? Explain the pull-based deployment model.

Answer

GitOps uses Git as the single source of truth for declarative infrastructure and applications. Core principles: 1) Declarative - desired state defined in Git. 2) Versioned - all changes tracked via Git history. 3) Automated - agents automatically apply changes. 4) Reconciliation - controllers continuously sync actual state to desired state. Pull-based model: agents (ArgoCD, Flux) run inside the cluster, pull changes from Git, and apply them. This is more secure than push-based CI/CD as the cluster doesn't need external access.

Why This Matters

GitOps treats operations like software development - infrastructure changes go through pull requests, code review, and audit trails. The pull model is a key differentiator: instead of CI pipelines pushing to clusters (requiring credentials), cluster agents pull from Git. This improves security and enables self-healing - if someone manually changes a resource, the GitOps controller reverts it to match Git.

Code Examples

ArgoCD Application

yaml

Flux Kustomization

yaml

Common Mistakes

Committing secrets to Git (use sealed secrets or external secrets)
Not setting up proper RBAC for the GitOps controller
Mixing application and infrastructure repos inappropriately

Follow-up Questions

Interviewers often ask these as follow-up questions

How do you handle secrets in a GitOps workflow?
What is drift detection and why is it important?
How do you implement progressive delivery with GitOps?