Kubernetes API Monitoring

The Prometheus agent is configured to report numerous K8s metrics. Below is the YAML-based rule set that Catapult uses, including alert names, expression, timeframe, labels, and annotations which contain the description and summaries.

YAML

bash-5.0# cat k8s.yml
groups:
  - name: kube-apiserver
    rules:
#-----------------------------------   API server -------------------------------------

      - alert: KubeAPIServerDown
        expr: up{job="kube-apiserver"} offset 5m == 0
        for: 1m
        labels:
          severity: critical
          type: k8s
        annotations:
          description: Kubernetes API server down on cluster {{ $labels.cluster }}
          summary: "Cluster {{ $labels.cluster }}: Kube api server down on host {{ $labels.host }}"

      - alert: KubernetesApiServerErrors
        expr: sum(rate(apiserver_request_total{code=~"(4|5).."}[1m] offset 5m )) by (cluster, host) / sum(rate(apiserver_request_total[1m] offset 5m )) by (cluster, host) * 100 > 3
        for: 2m
        labels:
          severity: critical
          type: k8s
        annotations:
          summary: Kubernetes API server errors on cluster {{ $labels.cluster }}
          description: "Cluster {{ $labels.cluster }}: Kubernetes API server is experiencing high error rate on host {{ $labels.host }}"

      - alert: KubernetesApiClientErrors
        expr: (sum(rate(rest_client_requests_total{code=~"(4|5).."}[1m] offset 5m )) by (cluster, host) / sum(rate(rest_client_requests_total[1m] offset 5m )) by (cluster, host)) * 100 > 1
        for: 2m
        labels:
          severity: critical
          type: k8s
        annotations:
          summary: Kubernetes API client errors on cluster {{ $labels.cluster }}
          description: "Cluster {{ $labels.cluster }}: Kubernetes API client is experiencing high error rate on host {{ $labels.host }}"

#-----------------------------------   Scheduler -------------------------------------
      - alert: KubeSchedulerDown
        expr: up{job="kube-scheduler"} offset 5m == 0
        for: 1m
        labels:
          severity: critical
          type: k8s
        annotations:
          summary: Kubernetes Scheduler down on cluster {{ $labels.cluster }}
          description: "Cluster {{ $labels.cluster }}: Kube scheduler down on host {{ $labels.host }}"


#-----------------------------------   Controller -------------------------------------
      - alert: KubeControllerManagerDown
        expr: up{job="kube-controller"} offset 5m == 0
        for: 1m
        labels:
          severity: critical
          type: k8s
        annotations:
          summary: Kubernetes Controller down on cluster {{ $labels.cluster }}
          description: "Cluster {{ $labels.cluster }}: Kube controller down on host {{ $labels.host }}"
#-----------------------------------   KubeProxy -------------------------------------
      - alert: KubeProxyDown
        expr: up{job="kube-proxy"} offset 5m == 0
        for: 1m
        labels:
          severity: critical
          type: k8s
        annotations:
          summary: KubeProxy down on cluster {{ $labels.cluster }}
          description: "Cluster {{ $labels.cluster }}: kube proxy down on host {{ $labels.host }}"

      - alert: KubeProxyRuleSyncLatency
        expr: histogram_quantile(0.99, sum by(le, cluster, host) (rate(kubeproxy_sync_proxy_rules_duration_seconds_bucket[5m] offset 5m ))) > 60
        for: 2m
        labels:
         severity: warning
         type: k8s
        annotations:
          summary: Cluster {{ $labels.cluster }} is taking too long, on average, to apply kubernetes service rules to iptables.
          description: "Cluster {{ $labels.cluster }}: network rules synchronization slowing down, VALUE = {{ $value }} on host {{ $labels.host }}"bash-5.0#