Tag: devops

ENV bakes secrets into image layers that docker history shows to anyone. Use BuildKit secret mounts, runtime variables, or a real secrets manager.

The latest tag does not mean newest, it means whatever was pushed untagged. Why that breaks reproducible deploys and how to pin versions and digests.

Build ARM64 and AMD64 images from one machine using Docker buildx. Setup, syntax, pushing multi-arch manifests, and when you actually need it.

Master Docker HEALTHCHECK syntax. Learn what checks work, how to tune interval/timeout/retries, and integrate with orchestration.

Docker labels are free metadata for filtering, routing, and documentation. Learn label conventions and leverage them with filters and tools.

Docker layer caching explains most slow builds. Why copying files too early kills the cache, the layer ordering that fixes it, and a multi-stage benchmark.

A missing .dockerignore bloats build context, slows every build, and leaks secrets into images. One you can copy-paste, plus how to check context size.

daemon.json controls how the Docker daemon behaves, logging drivers, storage drivers, registry mirrors, and the options worth tuning.

Write bash scripts that don't silently fail, set -euo pipefail, error handling, input validation, and logging patterns for production scripts.

btmp logs failed logins and grows forever on internet-facing servers. Set up logrotate to keep it under control before your disk fills up.

Stop copy-pasting Ansible tasks across playbooks, use include_tasks, import_tasks, and roles to keep your automation DRY and maintainable.

Bridge, host, overlay, macvlan, and none, every Docker network mode explained with real use cases from beginner to production.