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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Guided Exercise: Trace the Counts Through a Sequence of Commands
This is a paper exercise — commit to your answer before checking it in the Lab.
Your task
Starting from a completely clean system (no images, no containers), predict the number of IMAGES and the number of CONTAINERS after each step:
docker pull redis:alpinedocker run -d --name cache1 redis:alpinedocker run -d --name cache2 redis:alpinedocker rm -f cache1docker rmi redis:alpine(attempted whilecache2is still running)
A worked shape to check yourself against
- 1 image, 0 containers.
- 1 image, 1 container.
- 1 image, 2 containers.
- 1 image, 1 container (only
cache1removed). - This actually FAILS — Docker refuses to remove an image that a running container (
cache2) still depends on, specifically to prevent exactly this kind of accident. Still 1 image, 1 container, plus an error message.
Instructor Notes
Facilitation: Item 5 is the most valuable one — many students haven't seen Docker's dependency-protection behavior yet, and it's a good real safety feature to highlight.
Approximate timing: 8-10 minutes live discussion; 5 minutes self-paced.