[Feature] Phase 2: Custom Metrics Endpoint - Chrome & Chrome-Go Runners

[GrammaTonic]

📊 Phase 2: Custom Metrics Endpoint - Chrome & Chrome-Go Runners

Timeline: Week 2 (2025-11-23 to 2025-11-30)
Status: ⏳ Blocked by Phase 1
Goal: Extend metrics endpoint to Chrome and Chrome-Go runner types with identical functionality

🎯 Objectives

• Integrate metrics into Chrome runner variant
• Integrate metrics into Chrome-Go runner variant
• Configure unique port mappings to avoid conflicts (9092, 9093)
• Test concurrent multi-runner deployment

✅ Tasks (14 Total)

• TASK-013: Integrate metrics server and collector scripts into docker/entrypoint-chrome.sh
• TASK-014: Add EXPOSE 9091 to docker/Dockerfile.chrome
• TASK-015: Add EXPOSE 9091 to docker/Dockerfile.chrome-go
• TASK-016: Update docker/docker-compose.chrome.yml to expose port 9091 with unique host port mapping "9092:9091"
• TASK-017: Update docker/docker-compose.chrome-go.yml to expose port 9091 with unique host port mapping "9093:9091"
• TASK-018: Add environment variables RUNNER_TYPE=chrome and METRICS_PORT=9091 to chrome compose file
• TASK-019: Add environment variables RUNNER_TYPE=chrome-go and METRICS_PORT=9091 to chrome-go compose file
• TASK-020: Build Chrome runner: docker build -t github-runner:chrome-metrics-test -f docker/Dockerfile.chrome docker/
• TASK-021: Build Chrome-Go runner: docker build -t github-runner:chrome-go-metrics-test -f docker/Dockerfile.chrome-go docker/
• TASK-022: Deploy Chrome runner: docker-compose -f docker/docker-compose.chrome.yml up -d
• TASK-023: Deploy Chrome-Go runner: docker-compose -f docker/docker-compose.chrome-go.yml up -d
• TASK-024: Validate Chrome metrics: curl http://localhost:9092/metrics returns metrics with runner_type="chrome"
• TASK-025: Validate Chrome-Go metrics: curl http://localhost:9093/metrics returns metrics with runner_type="chrome-go"
• TASK-026: Test concurrent multi-runner deployment with all 3 types and verify unique metrics per runner

📋 Acceptance Criteria

• ✅ Chrome runner exposes metrics on port 9092
• ✅ Chrome-Go runner exposes metrics on port 9093
• ✅ All 3 runner types can run concurrently without port conflicts
• ✅ Metrics include correct runner_type label for each variant
• ✅ Performance overhead remains <1% CPU per runner

🔗 Dependencies

• BLOCKED BY: Phase 1 (must complete TASK-001 through TASK-012)

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Part of: Prometheus Monitoring Implementation (v2.3.0)