Installs the Prometheus Adapter for the Custom Metrics API. Custom metrics are used in Kubernetes by Horizontal Pod Autoscalers to scale workloads based upon your own metric pulled from an external metrics provider like Prometheus. This chart complements the metrics-server chart that provides resource only metrics.

Kubernetes 1.11+

To install the chart with the release name my-release:

$ helm install --name my-release stable/prometheus-adapter

This command deploys the prometheus adapter with the default configuration. The configuration section lists the parameters that can be configured during installation.

To use the chart, ensure the prometheus.url and prometheus.port are configured with the correct Prometheus service endpoint. If Prometheus is exposed under HTTPS the host's CA Bundle must be exposed to the container using extraVolumes and extraVolumeMounts.

Additionally, the chart comes with a set of default rules out of the box but they may pull in too many metrics or not map them correctly for your needs. Therefore, it is recommended to populate rules.custom with a list of rules (see the config document for the proper format).

Finally, to configure your Horizontal Pod Autoscaler to use the custom metric, see the custom metrics section of the HPA walkthrough.

The Prometheus Adapter can serve three different metrics APIs:

Enabling this option will cause custom metrics to be served at /apis/custom.metrics.k8s.io/v1beta1. Enabled by default when rules.default is true, but can be customized by populating rules.custom:

rules:
  custom:
  - seriesQuery: '{__name__=~"^some_metric_count$"}'
    resources:
      template: <<.Resource>>
    name:
      matches: ""
      as: "my_custom_metric"
    metricsQuery: sum(<<.Series>>{<<.LabelMatchers>>}) by (<<.GroupBy>>)

Enabling this option will cause external metrics to be served at /apis/external.metrics.k8s.io/v1beta1. Can be enabled by populating rules.external:

rules:
  external:
  - seriesQuery: '{__name__=~"^some_metric_count$"}'
    resources:
      template: <<.Resource>>
    name:
      matches: ""
      as: "my_external_metric"
    metricsQuery: sum(<<.Series>>{<<.LabelMatchers>>}) by (<<.GroupBy>>)

Enabling this option will cause resource metrics to be served at /apis/metrics.k8s.io/v1beta1. Resource metrics will allow pod CPU and Memory metrics to be used in Horizontal Pod Autoscalers as well as the kubectl top command. Can be enabled by populating rules.resource:

rules:
  resource:
    cpu:
      containerQuery: sum(rate(container_cpu_usage_seconds_total{<<.LabelMatchers>>}[3m])) by (<<.GroupBy>>)
      nodeQuery: sum(rate(container_cpu_usage_seconds_total{<<.LabelMatchers>>, id='/'}[3m])) by (<<.GroupBy>>)
      resources:
        overrides:
          instance:
            resource: node
          namespace:
            resource: namespace
          pod_name:
            resource: pod
      containerLabel: container_name
    memory:
      containerQuery: sum(container_memory_working_set_bytes{<<.LabelMatchers>>}) by (<<.GroupBy>>)
      nodeQuery: sum(container_memory_working_set_bytes{<<.LabelMatchers>>,id='/'}) by (<<.GroupBy>>)
      resources:
        overrides:
          instance:
            resource: node
          namespace:
            resource: namespace
          pod_name:
            resource: pod
      containerLabel: container_name
    window: 3m

NOTE: Setting a value for rules.resource will also deploy the resource metrics API service, providing the same functionality as metrics-server. As such it is not possible to deploy them both in the same cluster.

To uninstall/delete the my-release deployment:

$ helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

The following table lists the configurable parameters of the Prometheus Adapter chart and their default values.

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

$ helm install --name my-release \
  --set logLevel=1 \
 stable/prometheus-adapter

Alternatively, a YAML file that specifies the values for the above parameters can be provided while installing the chart. For example,

$ helm install --name my-release -f values.yaml stable/prometheus-adapter