Scraping custom metrics

Let groundcover automatically scrape your custom metrics

groundcover can scrape your custom metrics by deploying a metrics scraper (vmagent by Victoria Metrics) that will automatically scrape prometheus targets.

vmagent is fully compatible with prometheus scrape job syntax - more can be found here.

Enabling custom metrics scraping

The following helm override enables custom metrics scraping

custom-metrics:
  enabled: true

Using CLI

Scrape your custom metrics using groundcover CLI (using default scrape jobs):

groundcover deploy --custom-metrics

Using Helm

Using Helm (Upgrading existing installation)

Either create a new custom-values.yaml or edit your existing groundcover values.yaml

helm upgrade groundcover groundcover/groundcover -n groundcover -f values.yaml --reuse-values

Autodiscovery

Ensure that the Kubernetes resources that contain your Prometheus exporters have been deployed with the following annotations to enable scraping

annotations:
  prometheus.io/scrape: "true"
  prometheus.io/port: "<port>"
  prometheus.io/path: "<metrics-path>" // Optional, if path is not /metrics

By default, the following scrape jobs are deployed when enabling custom-metrics:

Starting November 25th 2024, kubernetes-pods scraping job will be the only scrape job that is enabled out of the box when activating custom metrics scraping. You can add back the legacy scrape jobs under extraScrapeConfigs section as described in Using custom scrape jobs

custom-metrics:
  enabled: true
  config:
    scrape_configs:
      - job_name: "kubernetes-apiservers"
        honor_labels: true  
        kubernetes_sd_configs:
          - role: endpoints
        scheme: https
        tls_config:
          ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
          insecure_skip_verify: true
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        relabel_configs:
          - action: drop
            source_labels:
              - __meta_kubernetes_pod_label_app_kubernetes_io_part_of
            regex: groundcover
          - source_labels:
              [
                __meta_kubernetes_namespace,
                __meta_kubernetes_service_name,
                __meta_kubernetes_endpoint_port_name,
              ]
            action: keep
            regex: default;kubernetes;https
      - job_name: "kubernetes-nodes"
        honor_labels: true
        scheme: https
        tls_config:
          ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
          insecure_skip_verify: true
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        kubernetes_sd_configs:
          - role: node
        relabel_configs:
          - action: drop
            source_labels:
              - __meta_kubernetes_pod_label_app_kubernetes_io_part_of
            regex: groundcover
          - action: labelmap
            regex: __meta_kubernetes_node_label_(.+)
          - target_label: __address__
            replacement: kubernetes.default.svc:443
          - source_labels: [__meta_kubernetes_node_name]
            regex: (.+)
            target_label: __metrics_path__
            replacement: /api/v1/nodes/$1/proxy/metrics
      - job_name: "kubernetes-service-endpoints"
        honor_labels: true
        kubernetes_sd_configs:
          - role: endpointslices
        relabel_configs:
          - action: drop
            source_labels:
              - __meta_kubernetes_pod_label_app_kubernetes_io_part_of
            regex: groundcover
          - action: drop
            source_labels: [__meta_kubernetes_pod_container_init]
            regex: true
          - source_labels:
              [__meta_kubernetes_service_annotation_prometheus_io_scrape]
            action: keep
            regex: true
          - source_labels:
              [__meta_kubernetes_service_annotation_prometheus_io_scheme]
            action: replace
            target_label: __scheme__
            regex: (https?)
          - source_labels:
              [__meta_kubernetes_service_annotation_prometheus_io_path]
            action: replace
            target_label: __metrics_path__
            regex: (.+)
          - source_labels:
              [
                __address__,
                __meta_kubernetes_service_annotation_prometheus_io_port,
              ]
            action: replace
            target_label: __address__
            regex: ([^:]+)(?::\d+)?;(\d+)
            replacement: $1:$2
          - action: labelmap
            regex: __meta_kubernetes_service_label_(.+)
          - source_labels: [__meta_kubernetes_pod_name]
            target_label: pod
          - source_labels: [__meta_kubernetes_pod_container_name]
            target_label: container
          - source_labels: [__meta_kubernetes_namespace]
            target_label: namespace
          - source_labels: [__meta_kubernetes_service_name]
            target_label: service
          - source_labels: [__meta_kubernetes_service_name]
            target_label: job
            replacement: ${1}
          - source_labels: [__meta_kubernetes_pod_node_name]
            action: replace
            target_label: node
      - job_name: "kubernetes-service-endpoints-slow"
        honor_labels: true
        scrape_interval: 5m
        scrape_timeout: 30s
        kubernetes_sd_configs:
          - role: endpointslices
        relabel_configs:
          - action: drop
            source_labels:
              - __meta_kubernetes_pod_label_app_kubernetes_io_part_of
            regex: groundcover
          - action: drop
            source_labels: [__meta_kubernetes_pod_container_init]
            regex: true
          - source_labels:
              [__meta_kubernetes_service_annotation_prometheus_io_scrape_slow]
            action: keep
            regex: true
          - source_labels:
              [__meta_kubernetes_service_annotation_prometheus_io_scheme]
            action: replace
            target_label: __scheme__
            regex: (https?)
          - source_labels:
              [__meta_kubernetes_service_annotation_prometheus_io_path]
            action: replace
            target_label: __metrics_path__
            regex: (.+)
          - source_labels:
              [
                __address__,
                __meta_kubernetes_service_annotation_prometheus_io_port,
              ]
            action: replace
            target_label: __address__
            regex: ([^:]+)(?::\d+)?;(\d+)
            replacement: $1:$2
          - action: labelmap
            regex: __meta_kubernetes_service_label_(.+)
          - source_labels: [__meta_kubernetes_pod_name]
            target_label: pod
          - source_labels: [__meta_kubernetes_pod_container_name]
            target_label: container
          - source_labels: [__meta_kubernetes_namespace]
            target_label: namespace
          - source_labels: [__meta_kubernetes_service_name]
            target_label: service
          - source_labels: [__meta_kubernetes_service_name]
            target_label: job
            replacement: ${1}
          - source_labels: [__meta_kubernetes_pod_node_name]
            action: replace
            target_label: node
      - job_name: "kubernetes-services"
        honor_labels: true
        metrics_path: /probe
        params:
          module: [http_2xx]
        kubernetes_sd_configs:
          - role: service
        relabel_configs:
          - action: drop
            source_labels:
              - __meta_kubernetes_pod_label_app_kubernetes_io_part_of
            regex: groundcover
          - source_labels:
              [__meta_kubernetes_service_annotation_prometheus_io_probe]
            action: keep
            regex: true
          - source_labels: [__address__]
            target_label: __param_target
          - target_label: __address__
            replacement: blackbox
          - source_labels: [__param_target]
            target_label: instance
          - action: labelmap
            regex: __meta_kubernetes_service_label_(.+)
          - source_labels: [__meta_kubernetes_namespace]
            target_label: namespace
          - source_labels: [__meta_kubernetes_service_name]
            target_label: service
      - job_name: "kubernetes-pods"
        honor_labels: true
        kubernetes_sd_configs:
          - role: pod
        relabel_configs:
          - action: drop
            source_labels:
              - __meta_kubernetes_pod_label_app_kubernetes_io_part_of
            regex: groundcover
          - action: drop
            source_labels: [__meta_kubernetes_pod_container_init]
            regex: true
          - source_labels:
              [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
            action: keep
            regex: true
          - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
            action: replace
            target_label: __metrics_path__
            regex: (.+)
          - source_labels:
              [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
            action: replace
            regex: ([^:]+)(?::\d+)?;(\d+)
            replacement: $1:$2
            target_label: __address__
          - action: labelmap
            regex: __meta_kubernetes_pod_label_(.+)
          - source_labels: [__meta_kubernetes_pod_name]
            target_label: pod
          - source_labels: [__meta_kubernetes_pod_container_name]
            target_label: container
          - source_labels: [__meta_kubernetes_namespace]
            target_label: namespace
          - source_labels: [__meta_kubernetes_service_name]
            target_label: service
          - source_labels: [__meta_kubernetes_service_name]
            target_label: job
            replacement: ${1}
          - source_labels: [__meta_kubernetes_pod_node_name]
            action: replace
            target_label: node

Disable autodiscovery scrape jobs

In case you're interested in disabling autodiscovery scrape jobs, provide the below override

Disabling custom-metrics scrape jobs allows you to scale the custom-metrics deployment horizontally.

custom-metrics:
  enabled: true
  config:
    scrape_configs: []

Using custom scrape jobs

in case you're interested in deploying custom scrape jobs, create/add the following override

custom-metrics:
  enabled: true
  extraScrapeConfigs:
  - job_name: "custom-scrape-job"
  ...

Cardinality limits

In order to safeguard groundcover's performance, there are default limitations on metrics ingestion in place.

remoteWrite.maxDailySeries: "1000000" # limiting daily churn rate.
remoteWrite.maxHourlySeries: "100000" # limiting the number of active time series.

Increasing metrics cardinality

In order to increase metrics resolution, you can implement the following overrides

Increasing cardinality parameters will increase memory/cpu consumption and might cause OOMKills/CPU Throttling.

Please use with caution and increase the custom metrics agent/metrics server resources accordingly

custom-metrics:
  enabled: true
  extraArgs:
    remoteWrite.maxDailySeries: "<custom value>"
    remoteWrite.maxHourlySeries: "<custom value>"

In case you wish to increase metrics server / custom metrics resources, use the following overrides:

custom-metrics:
  resources:
    limits:
      cpu: <>
      memory: <>
    requests:
      cpu: <>
      memory: <>