🥇Prometheus: HTTP Iwwerwaachung iwwer Blackbox Exporter

Moien alleguer. Am Mee lancéiert OTUS Workshop iwwer Iwwerwaachung a Logbicher, souwuel Infrastruktur wéi och Uwendungen mat Zabbix, Prometheus, Grafana an ELK. An dëser Hisiicht deele mir traditionell nëtzlecht Material zum Thema.

Blackbox Exportateur fir Prometheus erlaabt Iech Iwwerwaachung vun externe Servicer iwwer HTTP, HTTPS, DNS, TCP, ICMP ëmzesetzen. An dësem Artikel weisen ech Iech wéi Dir HTTP / HTTPS Iwwerwaachung mat Blackbox Exporter opstellt. Mir starten de Blackbox Exporter zu Kubernetes.

D'Ëmwelt

Mir wäerten déi folgend brauchen:

Kubernetes
Prometheus Bedreiwer

Exporter Blackbox Konfiguratioun

Blackbox konfiguréieren via ConfigMap fir Astellungen http Web Servicer Iwwerwachung Modul.

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-blackbox-exporter
  labels:
    app: prometheus-blackbox-exporter
data:
  blackbox.yaml: |
    modules:
      http_2xx:
        http:
          no_follow_redirects: false
          preferred_ip_protocol: ip4
          valid_http_versions:
          - HTTP/1.1
          - HTTP/2
          valid_status_codes: []
        prober: http
        timeout: 5s

Modul http_2xx benotzt fir ze kontrolléieren datt de Webservice en HTTP 2xx Statuscode zréckginn. D'Blackbox Exporter Konfiguratioun gëtt méi am Detail beschriwwen Dokumentatioun.

E Blackbox Exporter an e Kubernetes Cluster z'installéieren

Beschreiwen Deployment и Service fir Deployment zu Kubernetes.

---
kind: Service
apiVersion: v1
metadata:
  name: prometheus-blackbox-exporter
  labels:
    app: prometheus-blackbox-exporter
spec:
  type: ClusterIP
  ports:
    - name: http
      port: 9115
      protocol: TCP
  selector:
    app: prometheus-blackbox-exporter

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus-blackbox-exporter
  labels:
    app: prometheus-blackbox-exporter
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus-blackbox-exporter
  template:
    metadata:
      labels:
        app: prometheus-blackbox-exporter
    spec:
      restartPolicy: Always
      containers:
        - name: blackbox-exporter
          image: "prom/blackbox-exporter:v0.15.1"
          imagePullPolicy: IfNotPresent
          securityContext:
            readOnlyRootFilesystem: true
            runAsNonRoot: true
            runAsUser: 1000
          args:
            - "--config.file=/config/blackbox.yaml"
          resources:
            {}
          ports:
            - containerPort: 9115
              name: http
          livenessProbe:
            httpGet:
              path: /health
              port: http
          readinessProbe:
            httpGet:
              path: /health
              port: http
          volumeMounts:
            - mountPath: /config
              name: config
        - name: configmap-reload
          image: "jimmidyson/configmap-reload:v0.2.2"
          imagePullPolicy: "IfNotPresent"
          securityContext:
            runAsNonRoot: true
            runAsUser: 65534
          args:
            - --volume-dir=/etc/config
            - --webhook-url=http://localhost:9115/-/reload
          resources:
            {}
          volumeMounts:
            - mountPath: /etc/config
              name: config
              readOnly: true
      volumes:
        - name: config
          configMap:
            name: prometheus-blackbox-exporter

Blackbox Exporter ka mat dem folgenden Kommando ofgesat ginn. Nummraum monitoring bezitt sech op Prometheus Operator.

kubectl --namespace=monitoring apply -f blackbox-exporter.yaml

Vergewëssert Iech datt all Servicer lafen mat dem folgenden Kommando:

kubectl --namespace=monitoring get all --selector=app=prometheus-blackbox-exporter

Blackbox kontrolléieren

Dir kënnt Zougang zum Blackbox Exporter Web Interface benotzen port-forward:

kubectl --namespace=monitoring port-forward svc/prometheus-blackbox-exporter 9115:9115

Connect mat der Blackbox Exporter Web Interface iwwer e Webbrowser op localhost: 9115.

Wann Dir op d'Adress gitt http://localhost:9115/probe?module=http_2xx&target=https://www.google.com, gesitt Dir d'Resultat vun der Kontroll vun der spezifizéierter URL (https://www.google.com).

Metresche Wäert probe_success gläich 1 heescht erfollegräich kontrolléieren. E Wäert vun 0 weist e Feeler un.

Prometheus opbauen

Nodeems mir de BlackBox Exporter ofgesat hunn, konfiguréiere mir Prometheus an prometheus-additional.yaml.

- job_name: 'kube-api-blackbox'
  scrape_interval: 1w
  metrics_path: /probe
  params:
    module: [http_2xx]
  static_configs:
   - targets:
      - https://www.google.com
      - http://www.example.com
      - https://prometheus.io
  relabel_configs:
   - source_labels: [__address__]
     target_label: __param_target
   - source_labels: [__param_target]
     target_label: instance
   - target_label: __address__
     replacement: prometheus-blackbox-exporter:9115 # The blackbox exporter.

Mir generéieren Secretbenotzt de folgende Kommando.

PROMETHEUS_ADD_CONFIG=$(cat prometheus-additional.yaml | base64)
cat << EOF | kubectl --namespace=monitoring apply -f -
apiVersion: v1
kind: Secret
metadata:
  name: additional-scrape-configs
type: Opaque
data:
  prometheus-additional.yaml: $PROMETHEUS_ADD_CONFIG
EOF

Mir uginn additional-scrape-configs fir Prometheus Bedreiwer benotzt additionalScrapeConfigs.

kubectl --namespace=monitoring edit prometheuses k8s
...
spec:
  additionalScrapeConfigs:
    key: prometheus-additional.yaml
    name: additional-scrape-configs

Mir ginn op d'Prometheus Web Interface a kontrolléieren d'Metriken an Ziler.

kubectl --namespace=monitoring port-forward svc/prometheus-k8s 9090:9090

Mir gesinn d'Metriken an d'Ziler vu Blackbox.

Regele fir Notifikatiounen derbäisetzen (Alarm)

Fir Notifikatiounen vum Blackbox Exporter ze kréien, addéiere mir Reegelen zum Prometheus Operator.

kubectl --namespace=monitoring edit prometheusrules prometheus-k8s-rules
...
  - name: blackbox-exporter
    rules:
    - alert: ProbeFailed
      expr: probe_success == 0
      for: 5m
      labels:
        severity: error
      annotations:
        summary: "Probe failed (instance {{ $labels.instance }})"
        description: "Probe failedn  VALUE = {{ $value }}n  LABELS: {{ $labels }}"
    - alert: SlowProbe
      expr: avg_over_time(probe_duration_seconds[1m]) > 1
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: "Slow probe (instance {{ $labels.instance }})"
        description: "Blackbox probe took more than 1s to completen  VALUE = {{ $value }}n  LABELS: {{ $labels }}"
    - alert: HttpStatusCode
      expr: probe_http_status_code <= 199 OR probe_http_status_code >= 400
      for: 5m
      labels:
        severity: error
      annotations:
        summary: "HTTP Status Code (instance {{ $labels.instance }})"
        description: "HTTP status code is not 200-399n  VALUE = {{ $value }}n  LABELS: {{ $labels }}"
    - alert: SslCertificateWillExpireSoon
      expr: probe_ssl_earliest_cert_expiry - time() < 86400 * 30
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: "SSL certificate will expire soon (instance {{ $labels.instance }})"
        description: "SSL certificate expires in 30 daysn  VALUE = {{ $value }}n  LABELS: {{ $labels }}"
    - alert: SslCertificateHasExpired
      expr: probe_ssl_earliest_cert_expiry - time()  <= 0
      for: 5m
      labels:
        severity: error
      annotations:
        summary: "SSL certificate has expired (instance {{ $labels.instance }})"
        description: "SSL certificate has expired alreadyn  VALUE = {{ $value }}n  LABELS: {{ $labels }}"
    - alert: HttpSlowRequests
      expr: avg_over_time(probe_http_duration_seconds[1m]) > 1
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: "HTTP slow requests (instance {{ $labels.instance }})"
        description: "HTTP request took more than 1sn  VALUE = {{ $value }}n  LABELS: {{ $labels }}"
    - alert: SlowPing
      expr: avg_over_time(probe_icmp_duration_seconds[1m]) > 1
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: "Slow ping (instance {{ $labels.instance }})"
        description: "Blackbox ping took more than 1sn  VALUE = {{ $value }}n  LABELS: {{ $labels }}"

An der Prometheus Web Interface, gitt op Status => Regelen a fannt d'Alarmregele fir Blackbox-Exporter.

Konfiguréieren Kubernetes API Server SSL Zertifikat Verfall Notifikatiounen

Loosst eis Kubernetes API Server SSL Zertifikat Oflaf Iwwerwaachung konfiguréieren. Et wäert Notifikatiounen eemol d'Woch schécken.

Füügt de Blackbox Exporter Modul fir Kubernetes API Server Authentifikatioun.

kubectl --namespace=monitoring edit configmap prometheus-blackbox-exporter
...
      kube-api:
        http:
          method: GET
          no_follow_redirects: false
          preferred_ip_protocol: ip4
          tls_config:
            insecure_skip_verify: false
            ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
          bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
          valid_http_versions:
          - HTTP/1.1
          - HTTP/2
          valid_status_codes: []
        prober: http
        timeout: 5s

Prometheus Scrape Konfiguratioun derbäi

- job_name: 'kube-api-blackbox'
  metrics_path: /probe
  params:
    module: [kube-api]
  static_configs:
   - targets:
      - https://kubernetes.default.svc/api
  relabel_configs:
   - source_labels: [__address__]
     target_label: __param_target
   - source_labels: [__param_target]
     target_label: instance
   - target_label: __address__
     replacement: prometheus-blackbox-exporter:9115 # The blackbox exporter.

Benotzt Prometheus Secret

PROMETHEUS_ADD_CONFIG=$(cat prometheus-additional.yaml | base64)
cat << EOF | kubectl --namespace=monitoring apply -f -
apiVersion: v1
kind: Secret
metadata:
  name: additional-scrape-configs
type: Opaque
data:
  prometheus-additional.yaml: $PROMETHEUS_ADD_CONFIG
EOF

Füügt Alarmregelen

kubectl --namespace=monitoring edit prometheusrules prometheus-k8s-rules
...
  - name: k8s-api-server-cert-expiry
    rules:
    - alert: K8sAPIServerSSLCertExpiringAfterThreeMonths
      expr: probe_ssl_earliest_cert_expiry{job="kube-api-blackbox"} - time() < 86400 * 90 
      for: 1w
      labels:
        severity: warning
      annotations:
        summary: "Kubernetes API Server SSL certificate will expire after three months (instance {{ $labels.instance }})"
        description: "Kubernetes API Server SSL certificate expires in 90 daysn  VALUE = {{ $value }}n  LABELS: {{ $labels }}"

Nëtzlech Adressen

Iwwerwachung an aloggen an Docker

Source: will.com