Logging & Observability mit Claude Code: Pino, Winston, OpenTelemetry 2026

# Prompt: "Erstelle Pino-Setup mit Request-ID-Tracking und Production/Development-Config" # logger.js const pino = require('pino'); const logger = pino({ level: process.env.LOG_LEVEL || 'info', // Development: lesbare Ausgabe transport: process.env.NODE_ENV !== 'production' ? { target: 'pino-pretty', options: { colorize: true } } : undefined, // Production: JSON (Loki/CloudWatch verarbeitet JSON) // Sensible Felder maskieren redact: { paths: ['password', 'token', '*.creditCard', '*.ssn'], censor: '[REDACTED]' }, // Basis-Felder für jedes Log base: { service: process.env.SERVICE_NAME || 'api', env: process.env.NODE_ENV } }); module.exports = logger; # Express Middleware: Request-ID + Timing const { randomUUID } = require('crypto'); app.use((req, res, next) => { const requestId = req.headers['x-request-id'] || randomUUID(); const start = Date.now(); // Child-Logger mit Request-Context req.log = logger.child({ requestId, method: req.method, url: req.url, userId: req.user?.id }); res.on('finish', () => { req.log.info({ status: res.statusCode, duration: Date.now() - start }, 'request completed'); }); next(); });

# FALSCH — schwer zu filtern: logger.error(`User ${userId} kann Bestellung ${orderId} nicht stornieren: ${error.message}`); # RICHTIG — strukturiert, filterbar: logger.error({ event: 'order.cancel.failed', userId, orderId, errorCode: error.code, errorMessage: error.message, stack: error.stack }, 'Order cancellation failed'); # Warum: In Grafana/Kibana/Loki kannst du filtern: # {event="order.cancel.failed", userId="123"} # Freitext-Suche in Strings ist langsam und unzuverlässig

# Prompt: "Richte OpenTelemetry für Node.js ein — Traces zu Grafana Tempo" # instrumentation.js (vor allem anderen laden!) const { NodeSDK } = require('@opentelemetry/sdk-node'); const { OTLPTraceExporter } = require('@opentelemetry/exporter-trace-otlp-http'); const { HttpInstrumentation } = require('@opentelemetry/instrumentation-http'); const { ExpressInstrumentation } = require('@opentelemetry/instrumentation-express'); const { PgInstrumentation } = require('@opentelemetry/instrumentation-pg'); const sdk = new NodeSDK({ serviceName: 'order-service', traceExporter: new OTLPTraceExporter({ url: process.env.OTEL_EXPORTER_OTLP_ENDPOINT // Grafana Tempo / Jaeger }), instrumentations: [ new HttpInstrumentation(), // Alle HTTP-Requests new ExpressInstrumentation(), // Express Routen new PgInstrumentation() // PostgreSQL Queries ] }); sdk.start(); // node --require ./instrumentation.js server.js

# Manueller Span für Business-Logik: const { trace } = require('@opentelemetry/api'); const tracer = trace.getTracer('order-service'); async function processOrder(orderId) { return tracer.startActiveSpan('process-order', async (span) => { span.setAttribute('order.id', orderId); try { const result = await doProcessing(orderId); span.setAttribute('order.status', 'success'); return result; } catch (err) { span.recordException(err); span.setStatus({ code: SpanStatusCode.ERROR }); throw err; } finally { span.end(); } }); }

# prom-client für Node.js Metrics const { Counter, Histogram, register } = require('prom-client'); const httpRequests = new Counter({ name: 'http_requests_total', help: 'Total HTTP requests', labelNames: ['method', 'route', 'status'] }); const responseTime = new Histogram({ name: 'http_response_duration_seconds', help: 'HTTP response times', buckets: [0.05, 0.1, 0.3, 0.5, 1, 2, 5] }); // Business Metric: Orders pro Minute const ordersProcessed = new Counter({ name: 'orders_processed_total', help: 'Total orders processed', labelNames: ['status', 'payment_method'] }); // Metrics-Endpoint für Prometheus Scraping: app.get('/metrics', async (req, res) => { res.set('Content-Type', register.contentType); res.end(await register.metrics()); });