GitOps Principles and Implementation

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

DevOpsintermediate

// interview question

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

Sample 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

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: myapp
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/org/k8s-manifests
    targetRevision: main
    path: apps/myapp/overlays/prod
  destination:
    server: https://kubernetes.default.svc
    namespace: production
  syncPolicy:
    automated:
      prune: true      # Delete resources removed from Git
      selfHeal: true   # Revert manual changes
    syncOptions:
    - CreateNamespace=true

Flux Kustomization

yaml

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: myapp
  namespace: flux-system
spec:
  interval: 5m
  path: ./apps/myapp
  prune: true
  sourceRef:
    kind: GitRepository
    name: infrastructure
  healthChecks:
  - apiVersion: apps/v1
    kind: Deployment
    name: myapp
    namespace: production

Common mistakes to avoid

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

Likely follow-ups

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?

Answer out loud first, then check yourself against the model answer.

Practice all Mid-Level questions More DevOps questions

#gitops#argocd#flux#ci-cd#kubernetes

Also worth your time on this topic

Checklist

GitOps Implementation Checklist

Comprehensive checklist for implementing GitOps practices with repository structure, sync policies, secret management, and deployment strategies.

60-90 minutes

Exercise

GitOps with ArgoCD - Automated Kubernetes Deployments

Implement GitOps workflows using ArgoCD for automated, declarative, and auditable Kubernetes application deployments.

120 minutes

Article

GitOps with Argo CD: Structuring Your Repository for Multi-Environment Deployments

A practical guide to laying out your Git repository for Argo CD across dev, staging, and production. See real folder structures, Kustomize and Helm patterns, and the pitfalls that bite teams in production.

GitOps Principles and Implementation

More DevOps interview questions

Also worth your time on this topic

GitOps Implementation Checklist

GitOps with ArgoCD - Automated Kubernetes Deployments

GitOps with Argo CD: Structuring Your Repository for Multi-Environment Deployments