Prometheus: Metriken-Server einrichten

Prometheus ist ein Open-Source-Monitoring-System, das Metriken von Targets scraped und in einer Zeitreihen-Datenbank speichert. Ideal für Server, Container und Microservices.

Architektur

• Prometheus Server: Sammelt und speichert Metriken
• Exporters: Stellen Metriken bereit (Node, MySQL, etc.)
• Alertmanager: Verarbeitet Alerts
• Grafana: Visualisierung (optional)

Installation

# Benutzer erstellen
sudo useradd --no-create-home --shell /bin/false prometheus

# Prometheus herunterladen
cd /tmp
wget https://github.com/prometheus/prometheus/releases/download/v2.48.0/prometheus-2.48.0.linux-amd64.tar.gz
tar xvf prometheus-2.48.0.linux-amd64.tar.gz

# Dateien verschieben
sudo mv prometheus-2.48.0.linux-amd64/prometheus /usr/local/bin/
sudo mv prometheus-2.48.0.linux-amd64/promtool /usr/local/bin/
sudo mkdir /etc/prometheus /var/lib/prometheus
sudo mv prometheus-2.48.0.linux-amd64/consoles /etc/prometheus/
sudo mv prometheus-2.48.0.linux-amd64/console_libraries /etc/prometheus/

# Berechtigungen
sudo chown -R prometheus:prometheus /etc/prometheus /var/lib/prometheus

Konfiguration

sudo nano /etc/prometheus/prometheus.yml

global:
  scrape_interval: 15s
  evaluation_interval: 15s

alerting:
  alertmanagers:
    - static_configs:
        - targets:
          # - alertmanager:9093

rule_files:
  # - "alerts.yml"

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

  - job_name: "node"
    static_configs:
      - targets: ["localhost:9100"]

Systemd Service

sudo nano /etc/systemd/system/prometheus.service

[Unit]
Description=Prometheus
Wants=network-online.target
After=network-online.target

[Service]
User=prometheus
Group=prometheus
Type=simple
ExecStart=/usr/local/bin/prometheus \
    --config.file=/etc/prometheus/prometheus.yml \
    --storage.tsdb.path=/var/lib/prometheus/ \
    --web.console.templates=/etc/prometheus/consoles \
    --web.console.libraries=/etc/prometheus/console_libraries \
    --storage.tsdb.retention.time=30d

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl start prometheus
sudo systemctl enable prometheus

Node Exporter installieren

# Download
wget https://github.com/prometheus/node_exporter/releases/download/v1.7.0/node_exporter-1.7.0.linux-amd64.tar.gz
tar xvf node_exporter-1.7.0.linux-amd64.tar.gz
sudo mv node_exporter-1.7.0.linux-amd64/node_exporter /usr/local/bin/

# Service erstellen
sudo nano /etc/systemd/system/node_exporter.service

[Unit]
Description=Node Exporter
After=network.target

[Service]
User=prometheus
Type=simple
ExecStart=/usr/local/bin/node_exporter

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl start node_exporter
sudo systemctl enable node_exporter

PromQL Grundlagen

# Aktuelle CPU-Auslastung
100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)

# RAM-Nutzung
node_memory_MemTotal_bytes - node_memory_MemAvailable_bytes

# Disk I/O
rate(node_disk_read_bytes_total[5m])

# Netzwerk Traffic
rate(node_network_receive_bytes_total[5m])

# HTTP Requests pro Sekunde
rate(http_requests_total[5m])

# Top 5 nach CPU
topk(5, sum by (instance) (rate(node_cpu_seconds_total[5m])))

Alerting Rules

# /etc/prometheus/alerts.yml
groups:
  - name: server_alerts
    rules:
      - alert: HighCPU
        expr: 100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 80
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High CPU on {{ $labels.instance }}"
          description: "CPU > 80% for 5 minutes"

      - alert: DiskSpaceLow
        expr: (node_filesystem_avail_bytes / node_filesystem_size_bytes) * 100 < 10
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "Low disk space on {{ $labels.instance }}"

Weitere Exporter

Zugriff

# Web UI
http://SERVER-IP:9090

# Targets prüfen
http://SERVER-IP:9090/targets

# Metriken-Endpunkt
http://SERVER-IP:9090/metrics

Weitere Hilfe

• 📖 Prometheus Dokumentation
• 📧 E-Mail: support@enjyn.de