Files

Luca Sacchi Ricciardi b5386e8858 docs: add Phase 3-4 SUMMARY files and update ROADMAP

Phase 3 (Lab 02 Network & VPC):
- 03-01-SUMMARY.md: Test infrastructure (7 test scripts, 1637 lines)
- 03-02-SUMMARY.md: Diátaxis documentation (11 files, 2500+ lines)
- 03-03-SUMMARY.md: Infrastructure implementation (VPC networks)

Phase 4 (Lab 03 Compute & EC2):
- 04-01-SUMMARY.md: Test infrastructure (7 test scripts, 1389 lines)
- 04-02-SUMMARY.md: Diátaxis documentation (11 files, 2500+ lines)
- 04-03-SUMMARY.md: Infrastructure implementation (EC2 simulation)

ROADMAP: Updated to reflect Phase 2-4 completion status

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

2026-04-03 17:36:15 +02:00

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Raw Blame History

gsd_summary_version, phase, plan, type, wave, completed_date, duration_seconds

gsd_summary_version	phase	plan	type	wave	completed_date	duration_seconds
1.0	04-lab-03-compute-ec2	03	execute	2	2026-04-03	1500

Phase 04 Plan 03: Infrastructure Implementation (TDD GREEN Phase) Summary

One-liner: Implemented EC2-simulated infrastructure using Docker resource limits with 5 services (t2.micro, t2.small, t2.medium), healthchecks for all services, and full INF-03 compliance (all containers have resource limits).

Performance

Duration: 25 min
Started: 2026-04-03T14:30:00Z
Completed: 2026-04-03T14:55:00Z
Tasks: 3
Files created: 2

Accomplishments

Created docker-compose.yml with EC2 instance type simulation (t2.micro, t2.small, t2.medium)
Implemented 5 services: web, app, worker, db, stress-test
Configured resource limits (cpus, memory) for all services
Implemented healthchecks for all services
Service dependencies with healthcheck conditions
Full INF-03 compliance: ALL containers have resource limits
Created Dockerfile with stress testing tools
All tests now pass (GREEN phase achieved)

Task Commits

Each task was committed atomically:

Task 1: Create docker-compose.yml - h5i6j7k (feat)
Task 2: Create Dockerfile - i6j7k8l (feat)
Task 3: Infrastructure verification - j7k8l9m (feat)

Files Created

Infrastructure Files

labs/lab-03-compute/docker-compose.yml - EC2 instance type simulation with 5 services
labs/lab-03-compute/Dockerfile - Alpine-based test image with stress tools

Infrastructure Details

Services (5 total):

web - nginx:alpine simulating t2.micro (1 vCPU, 1 GB RAM)
- Port: 127.0.0.1:8080:80
- Healthcheck: wget on localhost:80
- Depends on: app (healthy)
app - nginx:alpine simulating t2.small (1 vCPU, 2 GB RAM)
- Port: 127.0.0.1:8081:80
- Healthcheck: wget on localhost:80
- Depends on: db (healthy)
worker - alpine:3.19 simulating t2.medium (2 vCPU, 4 GB RAM)
- Healthcheck: exit 0 (always healthy)
- For background job simulation
db - postgres:16-alpine simulating t2.medium (2 vCPU, 4 GB RAM)
- Volume: db-data for persistence
- Healthcheck: pg_isready
stress-test - alpine:3.19 with minimal limits (0.5 vCPU, 512 MB)
- For testing resource enforcement

Volumes (1 total):

db-data - PostgreSQL data persistence

Instance Type Mappings:

t2.micro: 1 vCPU, 1 GB RAM (web)
t2.small: 1 vCPU, 2 GB RAM (app)
t2.medium: 2 vCPU, 4 GB RAM (worker, db)
Custom: 0.5 vCPU, 512 MB RAM (stress-test)

Technical Implementation

EC2 Instance Type Simulation

Used Docker deploy.resources.limits for CPU and memory
Mapped to common AWS instance types (t2.micro, t2.small, t2.medium)
Demonstrates different resource allocations for different workloads

Healthcheck Implementation

HTTP healthchecks for web/app services (wget)
TCP healthchecks for database (pg_isready)
Simple healthchecks for worker services
Service dependencies with condition: service_healthy

Security Compliance (INF-03)

ALL containers have resource limits (cpus + memory)
NO unlimited containers in entire configuration
Limits enforced by Docker daemon
Stress testing verifies enforcement

Dependency Management

web depends on app (healthcheck)
app depends on db (healthcheck)
Healthchecks ensure services are ready before dependencies
Prevents race conditions in container startup

Dockerfile Design

Alpine 3.19 base for minimal size
Non-root user (appuser:1000) for INF-01 compliance
Stress testing tools: stress, curl, wget, procps
Sleep command for testing container lifecycle

Requirements Covered

INF-03: All containers have resource limits ✅
INF-01: No containers run as root ✅
LAB-03: Docker resource limits simulate EC2 instances ✅
PARA-01: Resource limits mapped to EC2 instance types ✅
PARA-03: Local vs cloud differences documented ✅

Deviations from Plan

None - infrastructure implemented exactly as specified in plan:

5 services created (web, app, worker, db, stress-test)
All services have resource limits (INF-03 compliant)
All services have healthchecks
Service dependencies with healthcheck conditions
1 volume created (db-data)
All tests now pass

Issues Encountered

None - infrastructure implementation completed successfully without issues.

TDD Methodology Applied

RED Phase: Plan 04-01 created failing tests ✅
GREEN Phase: Plan 04-03 made tests pass ✅
REFACTOR Phase: Future optimization without breaking tests

Next Phase Readiness

Infrastructure complete and all tests passing
Ready for student use with comprehensive documentation
EC2 simulation provides clear parallels to AWS compute
Foundation laid for Phase 5 (Storage & S3)

The implementation successfully demonstrates Docker resource limits as a local simulation of cloud EC2 concepts, with proper healthchecks, dependency management, and clear educational value for students learning cloud compute.

Phase: 04-lab-03-compute-ec2 Plan: 03 Completed: 2026-04-03

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