Goal

Add Lab 8 monitoring for QuickNotes using Prometheus, Grafana, one high-error-rate alert, a runbook, and bonus external synthetic monitoring.

Changes

• Added Prometheus config to scrape QuickNotes at quicknotes:8080/metrics
• Added Grafana datasource provisioning for Prometheus
• Added Grafana dashboard provisioning with a QuickNotes Golden Signals dashboard
• Added four dashboard panels: latency proxy, traffic, errors, and saturation
• Added Prometheus alert rule QuickNotesHighErrorRate
• Added runbook at docs/runbook/high-error-rate.md
• Updated submissions/lab8.md with Task 1, Task 2, and bonus evidence
• Reused the Lab 6 Dockerfile and healthcheck so QuickNotes can run as a healthy Compose service

Testing

• Ran docker compose config
• Ran docker compose up -d --build
• Verified QuickNotes was healthy with docker compose ps
• Verified Prometheus target was UP at http://localhost:9090/targets
• Verified Grafana auto-loaded the QuickNotes Golden Signals dashboard
• Generated traffic and confirmed dashboard graphs updated
• Triggered malformed POST /notes requests for more than 5 minutes
• Confirmed QuickNotesHighErrorRate moved to FIRING
• Verified Checkly synthetic monitoring through ngrok with 100% availability, 316 ms average latency, and 529 ms p95 latency

Checklist

• Title is a clear sentence (≤ 70 chars)
• Commits are signed (git log --show-signature)
• submissions/lab8.md updated