🥇Prometheus: Pagsubaybay sa HTTP sa pamamagitan ng Blackbox exporter

Kamusta kayong lahat. Sa Mayo inilunsad ang OTUS workshop sa pagsubaybay at pag-log, parehong imprastraktura at application gamit ang Zabbix, Prometheus, Grafana at ELK. Kaugnay nito, tradisyonal kaming nagbabahagi ng kapaki-pakinabang na materyal sa paksa.

Exporter ng blackbox para sa Prometheus ay nagbibigay-daan sa iyo na ipatupad ang pagsubaybay sa mga panlabas na serbisyo sa pamamagitan ng HTTP, HTTPS, DNS, TCP, ICMP. Sa artikulong ito, ipapakita ko sa iyo kung paano mag-set up ng pagsubaybay sa HTTP/HTTPS gamit ang Blackbox exporter. Ilulunsad namin ang Blackbox exporter sa Kubernetes.

Kapaligiran

Kakailanganin natin ang sumusunod:

Kubernetes
Operator ng Prometheus

Configuration ng blackbox ng exporter

Pag-configure ng Blackbox sa pamamagitan ng ConfigMap para sa mga setting http module ng pagsubaybay sa mga serbisyo sa web.

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

Modyul http_2xx ginagamit upang suriin na ang serbisyo sa web ay nagbabalik ng HTTP 2xx status code. Ang pagsasaayos ng blackbox exporter ay inilalarawan nang mas detalyado sa dokumentasyon.

Pag-deploy ng blackbox exporter sa isang Kubernetes cluster

Ilarawan Deployment и Service para sa deployment sa 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

Maaaring i-deploy ang blackbox exporter gamit ang sumusunod na command. Namespace monitoring ay tumutukoy sa Prometheus Operator.

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

Tiyaking tumatakbo ang lahat ng mga serbisyo gamit ang sumusunod na command:

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

Blackbox check

Maa-access mo ang web interface ng Blackbox exporter gamit ang port-forward:

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

Kumonekta sa Blackbox exporter web interface sa pamamagitan ng isang web browser sa localhost: 9115.

Kung pupunta ka sa address http://localhost:9115/probe?module=http_2xx&target=https://www.google.com, makikita mo ang resulta ng pagsuri sa tinukoy na URL (https://www.google.com).

Sukatan na halaga probe_success katumbas ng 1 ay nangangahulugang matagumpay na pagsusuri. Ang isang halaga ng 0 ay nagpapahiwatig ng isang error.

Pag-set up ng Prometheus

Pagkatapos i-deploy ang BlackBox exporter, i-configure namin ang Prometheus in 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.

Bumubuo tayo Secretgamit ang sumusunod na utos.

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

Ipinapahiwatig namin additional-scrape-configs para sa Prometheus Operator gamit additionalScrapeConfigs.

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

Pumunta kami sa web interface ng Prometheus at suriin ang mga sukatan at layunin.

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

Nakikita namin ang mga sukatan at layunin ng Blackbox.

Pagdaragdag ng mga panuntunan para sa mga notification (alerto)

Para makatanggap ng mga notification mula sa Blackbox exporter, magdaragdag kami ng mga panuntunan sa 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 }}"

Sa web interface ng Prometheus, pumunta sa Status => Mga Panuntunan at hanapin ang mga alituntunin ng alerto para sa blackbox-exporter.

Pag-configure ng Kubernetes API Server SSL Certificate Expiration Notifications

I-configure natin ang pagsubaybay sa pag-expire ng sertipiko ng SSL ng Kubernetes API Server. Magpapadala ito ng mga abiso minsan sa isang linggo.

Pagdaragdag ng module ng Blackbox exporter para sa Kubernetes API Server Authentication.

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

Pagdaragdag ng configuration ng Prometheus scrape

- 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.

Gamit ang 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

Pagdaragdag ng mga panuntunan sa alerto

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 }}"

Kapaki-pakinabang na mga link

Pagsubaybay at pag-log in sa Docker

Pinagmulan: www.habr.com