monitoring-setup

Monitoring Setup Agent

Autonomous infrastructure agent that configures complete observability pipeline: metrics instrumentation, distributed tracing, structured logging, alert rules, dashboards, SLO definitions, and runbooks.

Input

The /architect:setup-monitoring command passes:

{
  "components": [
    {
      "name": "api-server",
      "type": "backend",
      "language": "typescript",
      "framework": "express",
      "directory": "/path/to/project/api-server",
      "port": 3000
    }
  ],
  "monitoring_config": {
    "metrics_provider": "prometheus",
    "tracing_enabled": true,
    "tracing_provider": "opentelemetry",
    "error_tracking": "sentry",
    "log_aggregation": "loki",
    "alert_severity": "growth"
  },
  "project": {
    "name": "example-app",
    "stage": "growth"
  },
  "tech_stack": {
    "backend": ["Node.js", "Express"],
    "database": "PostgreSQL"
  }
}

Process

Step 1: Detect Existing Instrumentation

For each component, use Glob to check if monitoring code already exists:

• src/lib/metrics.ts, src/lib/tracing.ts, src/lib/logger.ts (Node.js)
• src/lib/metrics.py, src/lib/tracing.py, src/lib/logger.py (Python)
• pkg/metrics.go, pkg/tracing.go, pkg/logger.go (Go)

If files exist, check if they are stubs (empty or placeholder) or fully implemented:

• Stubs: append missing instrumentation
• Fully implemented: skip and report "already instrumented"

Step 2: Generate Metrics Instrumentation

Per component and language, generate src/lib/metrics.ts (or equivalent) with:

For Node.js (Express + Prometheus client):

// src/lib/metrics.ts
import promClient from 'prom-client';

// RED method: Rate, Errors, Duration
export const httpRequestDuration = new promClient.Histogram({
  name: 'http_request_duration_seconds',
  help: 'HTTP request latency in seconds',
  labelNames: ['method', 'route', 'status_code'],
  buckets: [0.001, 0.01, 0.05, 0.1, 0.5, 1, 2, 5]
});

export const httpRequestTotal = new promClient.Counter({
  name: 'http_requests_total',
  help: 'Total HTTP requests',
  labelNames: ['method', 'route', 'status_code']
});

export const httpRequestErrors = new promClient.Counter({
  name: 'http_request_errors_total',
  help: 'Total HTTP request errors',
  labelNames: ['method', 'route', 'error_code']
});

// USE method: Utilization, Saturation, Errors (for background workers)
export const dbConnectionPoolActive = new promClient.Gauge({
  name: 'db_connection_pool_active',
  help: 'Active database connections'
});

export const jobQueueLength = new promClient.Gauge({
  name: 'job_queue_length',
  help: 'Number of jobs in queue'
});

// Middleware for auto-instrumentation
export function metricsMiddleware(req, res, next) {
  const startTime = Date.now();
  res.on('finish', () => {
    const duration = (Date.now() - startTime) / 1000;
    const route = req.route?.path || req.url;
    
    httpRequestDuration.labels(req.method, route, res.statusCode).observe(duration);
    httpRequestTotal.labels(req.method, route, res.statusCode).inc();
    
    if (res.statusCode >= 400) {
      httpRequestErrors.labels(req.method, route, res.statusCode).inc();
    }
  });
  next();
}

// Export metrics endpoint
export function registerMetricsEndpoint(app) {
  app.get('/metrics', async (req, res) => {
    res.set('Content-Type', promClient.register.contentType);
    res.end(await promClient.register.metrics());
  });
}