End-to-End DevOps Project: Terraform, EKS and Argo CD

This is for you if

• You know Terraform, Kubernetes and CI separately but have never wired them into one system
• You're moving into DevOps, SRE or platform work and need a project that survives a technical interview
• You've used Argo CD or EKS someone else built and want to build it yourself once
• You want a cloud project with a real cost plan and a teardown you can trust

What's inside

• Three-repo layout (app, infra, GitOps) with clear ownership, change rates and blast radius
• Terraform with terraform-aws-modules v21 EKS, v6 VPC, ECR, GitHub OIDC trust and EKS Pod Identity
• GitHub Actions pipeline: test, build, Trivy gate, push to ECR with OIDC (no access keys), GitOps tag bump via GitHub App
• Argo CD app-of-apps with sync waves that actually wait, multi-source Helm add-ons and Kustomize dev/prod overlays
• External Secrets Operator with AWS Secrets Manager, plus a fake-provider version you can run on kind
• AWS Load Balancer Controller with one shared ALB, and kube-prometheus-stack with a ServiceMonitor and a real alert
• Promotion by pull request, three rollback methods compared, and two rehearsed production failures
• Hourly cost breakdown, cost levers, and an ordered teardown with a tag-based audit
• Resume bullets, README structure, demo script and 25 interview questions with follow-ups

After this guide you can

• Build and explain every hop from git push to a running pod behind an ALB
• Give CI and in-cluster controllers AWS access with OIDC and Pod Identity instead of stored keys
• Run a GitOps workflow with Argo CD app-of-apps, Kustomize overlays and PR-based promotion
• Roll back safely, diagnose the common failures, and tear everything down with proof
• Present the project on a resume and answer senior-level interview questions about it

Contents

1. The mental modelp. 5
2. The app repo: code, container and testsp. 9
3. The infra repo: Terraform for VPC, EKS and ECRp. 14
4. CI with GitHub Actions and OIDCp. 28
5. The GitOps repo: Kustomize overlays and Argo CD app-of-appsp. 35
6. Platform add-ons: secrets and ingressp. 51
7. Observability basicsp. 58
8. Promotion, rollback, cost control and teardownp. 62
9. Troubleshooting playbookp. 70
10. Production checklist and design decisionsp. 73
11. Presenting it: resume, README and interviewsp. 75
12. Interview questionsp. 77
13. Cheat sheet and 30-day planp. 85