CI/CD | John Nessime

Dockerfile Layer Caching: Why Every Build Reinstalls Everything

Post category:DevOps Docker Technical Guides

Your Dockerfile copies the lockfile before the source, and CI still reinstalls every dependency on every commit. That gap between a correctly ordered Dockerfile and a build that behaves as if it isn't comes down to five distinct failure families: ordering traps, a build context that poisons checksums, a cache that never reaches CI, cache mounts that vanish with the runner, and multi-stage export modes. Here is how invalidation actually works and how to prove which one is costing you.

Terraform Drift Detection That Nobody Mutes

Post category:DevOps Monitoring Technical Guides

Switching on Terraform drift detection takes one flag. Keeping engineers reading the output takes plan-mode choices, noise classification, severity routing by blast radius, and an alert that names who made the change.

CI/CD Pipeline Bottlenecks: Where Your Build Minutes Actually Go

Post category:Continuous Delivery DevOps Troubleshooting

The build duration graph looks fine and shipping is still slow. Most CI/CD pipeline bottlenecks are waiting, not working: queue time, caches that report a hit and deliver nothing, stage ordering nobody revisited, and required checks stuck at pending. Here is how to find yours.

Terraform Modules Worth Reusing (And the Ones That Cost You)

Post category:Cloud Computing DevOps Technical Guides

A module's real cost is not writing it, it's upgrading it. Five signals that separate reusable Terraform modules worth adopting from the ones your team will pin at an old version and never touch again, plus the state-address failure that makes version bumps dangerous.

GitLab CI vs GitHub Actions vs Jenkins: Choosing Without Regretting It Later

Post category:Cloud Computing DevOps Technical Guides

A practical comparison of GitLab CI, GitHub Actions and Jenkins that skips the feature table. What actually decides the choice is where your code lives, whether the runner can reach the deploy target, and who owns the control plane at 2am. Includes the cost mechanics, the security failure modes, and a decision procedure you can run in an afternoon.

Keep Kubernetes Secrets Out of Git Without Kidding Yourself

Post category:DevOps Kubernetes Technical Guides Web Security

Encrypting a Secret before you commit it only closes one of the five places that value comes to rest. Here is how to keep Kubernetes secrets out of Git properly: Sealed Secrets, SOPS and External Secrets compared honestly, the key-backup problem nobody plans for, and what to actually do when a credential is already in your history.

Two Sources of Truth: Git-Based WordPress Deployment From Local to Production

Post category:DevOps Technical Guides WordPress

A plugin quietly reverts after every deploy and nobody knows why. That is what happens when Git and wp-admin both think they own the file tree. Here is how to build a deployment workflow where the repo is the source of truth and the database only ever travels one way.

Your Deploy Key Is a Root Shell: GitHub Actions VPS Deployment Over SSH, Done Carefully

Post category:DevOps Technical Guides Web Security

A deploy key in GitHub secrets is a shell on your production server, handed to a container you don't control, running code from maintainers you've never met. Here's how to build the pipeline so a leaked key isn't worth much: forced commands, scoped sudo, pinned actions and a real approval gate.

Green Check, Broken Build: How to Build a Fail Fast Pipeline That Explains Why

Post category:DevOps Technical Guides Troubleshooting

A green pipeline that ships a broken build is worse than a red one. Here is how to order stages so failures surface in seconds, stop shell pipes from swallowing exit codes, and write failure output that tells the next engineer exactly what to fix.

A Secure-by-Default AWS Account Baseline in Terraform

Post category:Cloud Computing DevOps Web Security

A fresh AWS account ships wide open by default. Here are the seven decisions that make one defensible from the start — OIDC instead of static keys, encrypted state, an isolated database tier, free gateway endpoints — with a working Terraform reference implementation on GitHub.