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]>
30 lines
1.3 KiB
Markdown
30 lines
1.3 KiB
Markdown
# Guided Exercise: Diagnose Before You Recreate Anything
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This is a paper exercise — commit to a diagnostic plan before working in the Lab.
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## Your task
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A container `payments-api` is reported as "unreachable" by a teammate. Before touching anything,
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write out, in order, the exact commands you'd run to determine WHERE the problem actually is —
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using this module's and ROOT 02's tools.
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## A worked shape to check yourself against
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```
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docker ps --filter name=payments-api # is it even running?
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docker exec payments-api curl -sf localhost:PORT/ # does it work internally?
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docker port payments-api # is anything actually published?
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curl -sf http://localhost:PUBLISHED_PORT/ # does the published mapping actually work?
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```
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This sequence isolates each layer independently — running? working internally? published at
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all? published mapping actually functional? — exactly the same "isolate one variable at a time"
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discipline ROOT 02 Module 3 taught, applied here to containers specifically.
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## Instructor Notes
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**Facilitation:** This exercise is deliberately a direct copy of ROOT 02's diagnostic discipline
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— the value is students recognizing that connection themselves, not being told it explicitly.
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**Approximate timing:** 8-10 minutes live discussion; 5 minutes self-paced.
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