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typing

A hands-on lab that recreates the moving parts of a small content delivery network end-to-end: edge nodes, anycast-style request steering, tiered caching, origin shielding, and observability. Built to mirror the kind of work a Senior Network Engineer does at a CDN — but small enough to run on a single laptop with Docker Compose.

Think of it as a "CDN in a box" you can break, profile, and tune.

 ┌────────────┐ anycast-ish ┌────────────┐
 client ─► │ geo-LB │ ──────────────────────► │ edge PoP │ ──► cache hit ─► client
 └────────────┘ (lowest-latency map) │ (nginx) │
 │ └─────┬──────┘
 │ │ miss
 ▼ ▼
 metrics + logs ◄──── Prometheus ◄──── origin shield ──► origin
 │
 ▼
 Grafana

• Edges: Nginx with proxy_cache, stale-while-revalidate, conditional GETs
• Steering: weighted/geo map → nearest PoP (simulated RTT via tc netem)
• Shield: single mid-tier cache collapsing requests before they hit origin
• Provisioning: Ansible roles for repeatable PoP rollout
• Observability: Prometheus + Grafana dashboards (cache-hit %, TTFB p50/p95, origin RPS)

git clone https://github.com/1994-munk/edge-cdn-lab.git
cd edge-cdn-lab
docker compose up -d
./scripts/seed-traffic.sh # synthetic load across PoPs
open http://localhost:3000 # Grafana (admin/admin)

Provision a fresh PoP:

ansible-playbook -i inventories/lab ansible/site.yml --limit pop-fra

• docs/runbooks/cache-poisoning.md — invalidation & purge workflow
• docs/runbooks/pop-failover.md — pulling a PoP out of rotation
• docs/runbooks/origin-overload.md — shield tuning + request collapsing

• Multi-PoP Nginx with tiered cache
• Prometheus + Grafana dashboards
• Ansible provisioning
• QUIC / HTTP3 edge listener
• eBPF-based connection accounting
• Synthetic RUM beacon