ced4568andClaude Sonnet 5
682ef2de47
Adds all 8 ROOT 04 modules (why containers exist, images & containers, Docker CLI, container networking, container storage, Dockerfile & image build, Docker Compose, containers → Kubernetes) — 43 activities, using the nested Docker Engine Phase 6D built and tested. Modules 1, 2, and 8 are conceptual (no lab by design) — the honest bridge module (M8) explicitly names what Kubernetes adds beyond what this course already taught, without re-teaching Kubernetes itself. Adds 5 new hands-on Docker scenarios plus 2 MCQs, all against the real nested Docker Engine: docker-cli-basics (run/exec/inspect a real container), docker-container-networking (a genuine "works internally, unreachable from host" port-publishing failure, diagnosed and fixed by recreating the container with the correct `-p` flag), docker-container-storage (a real destroy/recreate cycle proving named-volume persistence, not just described), docker-build-image (a real Dockerfile, a real build, a real custom image run), and docker-compose-multiservice (a real two-service Compose application with a real published port). All tested end-to-end via the real scenario-validation API, including negative tests. Wires rootnode-containers-assessment (2 required + 4 random-draw scenarios) using the existing Phase 3B assessment engine. This completes the entire ROOT_ Foundations sequence (ROOT 01-04) — see docs/PHASE6E_ROOT_FOUNDATIONS_COMPLETION.md. Co-Authored-By: Claude Sonnet 5 <[email protected]>
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Knowledge Check: Container Storage
1. By default, what happens to data written inside a running container when that container is destroyed?
Answer: It's lost permanently — a container's writable layer is disposable by default; nothing persists unless a volume or bind mount was explicitly configured.
2. What's the actual difference between a bind mount and a named volume?
Answer: A bind mount connects a specific HOST filesystem path directly into the container (tightly coupled to that host's exact layout). A named volume is storage Docker manages independently of any specific host path, making it more portable and the production-appropriate choice.
3. Does docker stop (without removing) test whether a container's data actually persists?
Answer: No — stopping doesn't touch the writable layer at all. Only fully removing
(docker rm) and recreating the container is a real test of persistence.
4. What Kubernetes concept is this module's volume idea the direct foundation for?
Answer: PersistentVolume/PersistentVolumeClaim — the same persistence concept, generalized across an entire cluster instead of one machine.
Instructor Notes
Facilitation: Question 3 is worth emphasizing — it's a genuine, common mistake in verifying persistence claims.
Approximate timing: 5 minutes.