Making Metrics Available to Prometheus(4.0)

Metrics

Metrics can be made available for scraping by Prometheus in two ways:

• Through the automatic service discovery provided by the Prometheus stack

• By using raw scrape configurations

There are four sources of metrics:

• Platform pod

• Operator pods

• EC pod(s)

Making  Metrics Available to Prometheus Through the Stack

If the prometheus stack is deployed in your cluster, this is how the  metrics are made available to prometheus for scraping:

Making  metrics available to Prometheus

The metrics from the  platform and operator pods are automatically discoverable by Prometheus by using the PodMonitor and ServiceMonitor resources, which are automatically setup when installing or updating the helm chart.

If the Prometheus stack deployment requires matching by labels, the helm value global.metrics.monitor.labels can be used to set the required labels when installing  or updating of the helm chart.

Since the metrics from the EC pod(s) are exposed via Prometheus annotations (i.e. prometheus.io/scrape, prometheus.io/port and prometheus.io/path) rather than via PodMonitor/ServiceMonitor resources, Prometheus requires an additional scrape configuration to pick up these metrics.

Making  Metrics Available to Prometheus by Using Raw Scrape Configurations

If the Prometheus stack is not deployed in your cluster, a raw scrape configuration is used to make Prometheus pick up the platform metrics.

For this means that the  prometheus.io/scrape, prometheus.io/port and prometheus.io/path annotations need to be applied to the platform pod. These annotations are controlled through the helm chart via the jmx.export.* values and must not be set explicitly. Refer to the helm chart for further details.

helm upgrade --install kube-prometheus-stack prometheus-community/kube-prometheus-stack -f prometheus-values.yaml

prometheus:
  prometheusSpec:
    additionalScrapeConfigs:
      - job_name: ec-pods
        kubernetes_sd_configs:
          - role: pod
        relabel_configs:
          # maps to the 'prometheus.io/scrape: "true"' annotation on the EC pod
          - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
            action: keep
            regex: true
          # maps to the 'prometheus.io/path: /metrics' annotation on the EC pod
          - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
            action: replace
            target_label: __metrics_path__
            regex: (.+)
          # maps to the 'prometheus.io/port: "9090"' annotation on the EC pod
          - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
            action: replace
            regex: ([^:]+)(?::\d+)?;(\d+)
            replacement: $1:$2
            target_label: __address__
          # maps the pod name to the "pod" label on the metric
          - source_labels: [__meta_kubernetes_pod_name]
            action: replace
            target_label: pod
          # maps to all the labels of the EC pod - this is optional and not required for the scraping to happen
          - action: labelmap
            regex: __meta_kubernetes_pod_label_(.+)
    podMonitorSelector:
      matchLabels:
        prometheus: application-monitoring
    serviceMonitorSelector:
      matchLabels:
        prometheus: application-monitoring