Practical articles on Docker, Kubernetes, networking and CI/CD, written alongside the tools on this site.https://opsatlas.app/enhttps://opsatlas.app/blog/docker-multi-stage-builds/https://opsatlas.app/blog/docker-multi-stage-builds/Build in one stage, ship from another: multi-stage Dockerfiles for Node.js and Go, BuildKit cache mounts, test stages in CI and the pitfalls.Sun, 01 Nov 2026 00:00:00 GMTdockerdockerfilemulti-stage-buildsperformanceOpsAtlashttps://opsatlas.app/blog/dockerfile-mistakes-secrets-image-size/https://opsatlas.app/blog/dockerfile-mistakes-secrets-image-size/Six Dockerfile mistakes you can prove with docker history, inspect and top: leaked tokens, layers that never shrink, stale apt caches and slow stops.Sun, 01 Nov 2026 00:00:00 GMTdockerdockerfilesecuritycontainersOpsAtlashttps://opsatlas.app/blog/dockerfile-to-kubernetes/https://opsatlas.app/blog/dockerfile-to-kubernetes/Take a Node.js API from a first Dockerfile to validated Kubernetes manifests with four free OpsAtlas tools: lint, Compose, generate, validate.Sun, 01 Nov 2026 00:00:00 GMTkubernetesdockerdockerfiledocker-composeOpsAtlashttps://opsatlas.app/blog/first-kubernetes-deployment-and-service/https://opsatlas.app/blog/first-kubernetes-deployment-and-service/Run a container on a local Kubernetes cluster: generate a Deployment and Service, check them, apply them and watch Kubernetes keep the app running.Sun, 01 Nov 2026 00:00:00 GMTkubernetesdeploymentkindcontainersOpsAtlashttps://opsatlas.app/blog/local-dev-stack-docker-compose/https://opsatlas.app/blog/local-dev-stack-docker-compose/Run an API and Postgres together with one command: convert docker run to Compose, then add builds, health checks, startup order and a .env file.Sun, 01 Nov 2026 00:00:00 GMTdockerdocker-composepostgrescontainersOpsAtlashttps://opsatlas.app/blog/pin-docker-base-images-digest/https://opsatlas.app/blog/pin-docker-base-images-digest/Why node:22 can change under you, how to pin FROM lines to an immutable digest, and how Renovate or Dependabot keep pinned images patched.Sun, 01 Nov 2026 00:00:00 GMTdockerdockerfilesupply-chainrenovateOpsAtlashttps://opsatlas.app/blog/write-your-first-dockerfile/https://opsatlas.app/blog/write-your-first-dockerfile/Build a container image for a small Node.js API line by line, run it, then lint it and fix it to a perfect score. No Docker experience needed.Sun, 01 Nov 2026 00:00:00 GMTdockerdockerfilecontainersnodejsOpsAtlashttps://opsatlas.app/blog/debug-jwt-401-unauthorized/https://opsatlas.app/blog/debug-jwt-401-unauthorized/A valid-looking token, a 401 response. Seven common causes, from expiry and clock skew to the wrong audience and rotated keys, and how to check each.Sun, 25 Oct 2026 00:00:00 GMTjwtsecurityauthenticationtroubleshootingOpsAtlashttps://opsatlas.app/blog/debug-kubernetes-ingress-503/https://opsatlas.app/blog/debug-kubernetes-ingress-503/Trace a 503 or 502 from a Kubernetes Ingress through the Service and its endpoints to the pod, with the kubectl command to check each hop.Sun, 25 Oct 2026 00:00:00 GMTkubernetesingressnetworkingtroubleshootingOpsAtlashttps://opsatlas.app/blog/github-actions-matrix-required-checks/https://opsatlas.app/blog/github-actions-matrix-required-checks/Why a GitHub Actions matrix leaves pull requests stuck on "Expected — Waiting", how to make matrix jobs safe to require, and how to keep PR matrices small.Sun, 25 Oct 2026 00:00:00 GMTgithub-actionsci-cdbranch-protectionOpsAtlashttps://opsatlas.app/blog/kubernetes-cronjob-pitfalls/https://opsatlas.app/blog/kubernetes-cronjob-pitfalls/Why a Kubernetes CronJob runs at the wrong hour, runs twice, or stops running, and the CronJob settings that make scheduled jobs predictable.Sun, 25 Oct 2026 00:00:00 GMTkubernetescronschedulingbatch-jobsOpsAtlashttps://opsatlas.app/blog/kubernetes-readiness-liveness-probes/https://opsatlas.app/blog/kubernetes-readiness-liveness-probes/How readiness, liveness and startup probes differ, the probe mistakes that turn a slow database into a full outage, and safe settings to start from.Sun, 25 Oct 2026 00:00:00 GMTkubernetesreliabilityhealth-checksOpsAtlashttps://opsatlas.app/blog/plan-kubernetes-pod-service-cidr/https://opsatlas.app/blog/plan-kubernetes-pod-service-cidr/How to size the three IP ranges every Kubernetes cluster needs, why pod CIDRs run out first, and how to avoid overlaps with VPCs, VPNs and Docker.Sun, 25 Oct 2026 00:00:00 GMTkubernetesnetworkingcidrsubnetsOpsAtlashttps://opsatlas.app/blog/size-reserved-instance-commitment/https://opsatlas.app/blog/size-reserved-instance-commitment/Use hourly usage and one break-even number to decide how many instances to reserve, with a worked example of where the last commitment stops paying.Sun, 25 Oct 2026 00:00:00 GMTcloud-costfinopsawsreserved-instancesOpsAtlashttps://opsatlas.app/blog/yaml-1-1-vs-1-2-kubernetes-gotchas/https://opsatlas.app/blog/yaml-1-1-vs-1-2-kubernetes-gotchas/The same YAML file can mean different things to different parsers. How the 1.1 vs 1.2 split breaks Kubernetes, Compose and CI files, and how to spot it.Sun, 25 Oct 2026 00:00:00 GMTyamlkubernetesjsonOpsAtlashttps://opsatlas.app/blog/migrate-docker-run-to-docker-compose/https://opsatlas.app/blog/migrate-docker-run-to-docker-compose/A practical, step-by-step guide to turning a pile of docker run commands into one compose.yaml, and the five mistakes to fix along the way.Sat, 24 Oct 2026 00:00:00 GMTdockerdocker-composecontainersOpsAtlas