Prometheus + Grafana – Monitoring Stack einrichten 2025

Stack-Überblick

Prometheus:      Metriken-Datenbank (Pull-basiert)
Node Exporter:   Linux-Metriken (CPU, RAM, Disk)
Alertmanager:    Benachrichtigungen (E-Mail, Slack)
Grafana:         Dashboards und Visualisierung
cAdvisor:        Docker-Container-Metriken

Installation mit Docker Compose

# docker-compose.yml
services:
  prometheus:
    image: prom/prometheus:latest
    container_name: prometheus
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
      - ./rules:/etc/prometheus/rules
      - prometheus-data:/prometheus
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
      - '--storage.tsdb.retention.time=30d'
      - '--web.enable-lifecycle'
    ports:
      - "9090:9090"
    restart: unless-stopped

  grafana:
    image: grafana/grafana:latest
    container_name: grafana
    volumes:
      - grafana-data:/var/lib/grafana
    environment:
      GF_SECURITY_ADMIN_PASSWORD: sicheres-passwort
      GF_USERS_ALLOW_SIGN_UP: false
    ports:
      - "3000:3000"
    restart: unless-stopped

  node-exporter:
    image: prom/node-exporter:latest
    container_name: node-exporter
    volumes:
      - /proc:/host/proc:ro
      - /sys:/host/sys:ro
      - /:/rootfs:ro
    command:
      - '--path.procfs=/host/proc'
      - '--path.rootfs=/rootfs'
      - '--path.sysfs=/host/sys'
    ports:
      - "9100:9100"
    restart: unless-stopped

  cadvisor:
    image: gcr.io/cadvisor/cadvisor:latest
    container_name: cadvisor
    volumes:
      - /:/rootfs:ro
      - /var/run:/var/run:ro
      - /sys:/sys:ro
      - /var/lib/docker:/var/lib/docker:ro
    ports:
      - "8080:8080"
    restart: unless-stopped

  alertmanager:
    image: prom/alertmanager:latest
    container_name: alertmanager
    volumes:
      - ./alertmanager.yml:/etc/alertmanager/alertmanager.yml
    ports:
      - "9093:9093"
    restart: unless-stopped

volumes:
  prometheus-data:
  grafana-data:

prometheus.yml

# prometheus.yml
global:
  scrape_interval: 15s
  evaluation_interval: 15s

alerting:
  alertmanagers:
    - static_configs:
        - targets: ['alertmanager:9093']

rule_files:
  - 'rules/*.yml'

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']

  - job_name: 'node'
    static_configs:
      - targets: ['node-exporter:9100']
        labels:
          server: 'web-server-01'
      - targets: ['192.168.1.101:9100']
        labels:
          server: 'db-server-01'

  - job_name: 'cadvisor'
    static_configs:
      - targets: ['cadvisor:8080']

  - job_name: 'nginx'
    static_configs:
      - targets: ['192.168.1.10:9113']  # nginx-exporter

Alert-Regeln

# rules/server-alerts.yml
groups:
  - name: server
    rules:
      - alert: HighCPU
        expr: 100 - (avg by(instance)(rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 85
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Hohe CPU-Auslastung auf {{ $labels.instance }}"
          description: "CPU: {{ $value | humanize }}%"

      - alert: LowDiskSpace
        expr: (node_filesystem_avail_bytes / node_filesystem_size_bytes) * 100 < 10
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "Wenig Speicherplatz auf {{ $labels.instance }}"

      - alert: HighMemoryUsage
        expr: (1 - (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes)) * 100 > 90
        for: 5m
        labels:
          severity: warning

Alertmanager E-Mail

# alertmanager.yml
global:
  smtp_smarthost: 'mail.firma.de:587'
  smtp_from: '[email protected]'
  smtp_auth_username: '[email protected]'
  smtp_auth_password: 'passwort'

route:
  group_by: ['alertname', 'instance']
  group_wait: 30s
  group_interval: 5m
  repeat_interval: 4h
  receiver: 'email'

receivers:
  - name: 'email'
    email_configs:
      - to: '[email protected]'
        subject: '[Alert] {{ .GroupLabels.alertname }}'

Grafana Dashboards

Grafana → Dashboards → Import:
ID 1860 – Node Exporter Full (beliebtestes Dashboard)
ID 893  – Docker and system monitoring
ID 3662 – Prometheus 2.0 Overview

Eigenes Dashboard:
+ → Visualization → Time Series
PromQL Query: node_cpu_seconds_total

FAQ

Wie lange speichert Prometheus Metriken?
Standard: 15 Tage. Mit --storage.tsdb.retention.time=30d auf 30 Tage. Für Langzeit-Speicherung: Thanos oder VictoriaMetrics.

Fazit

Der Prometheus + Grafana Stack ist der Industriestandard für Server-Monitoring: mächtig, kostenlos und mit tausenden vorgefertigten Dashboards.

Monitoring und Observability für KMU in Heidelberg, Mannheim und der Rhein-Neckar-Region. Beratung anfragen.