MetricsTrait Custom Resource Definition

The MetricsTrait custom resource contains the configuration information needed to enable metrics for an application component. Component workloads configured with a MetricsTrait are setup to emit metrics through an endpoint that are scraped by a given Prometheus deployment. Here is a sample ApplicationConfiguration that specifies a MetricsTrait. To deploy an example application that demonstrates a MetricsTrait, see Hello World Helidon.

Note that if an ApplicationConfiguration does not specify a MetricsTrait, then a default MetricsTrait will be generated with values appropriate for the workload type.

apiVersion: core.oam.dev/v1alpha2
kind: ApplicationConfiguration
metadata:
  name: hello-helidon-appconf
  namespace: hello-helidon
  annotations:
    version: v1.0.0
    description: "Hello Helidon application"
spec:
  components:
    - componentName: hello-helidon-component
      traits:
        - trait:
            apiVersion: oam.verrazzano.io/v1alpha1
            kind: MetricsTrait
            spec:
                scraper: verrazzano-system/vmi-system-prometheus-0
        - trait:
            apiVersion: oam.verrazzano.io/v1alpha1
            kind: IngressTrait
            metadata:
              name: hello-helidon-ingress
            spec:
              rules:
                - paths:
                    - path: "/greet"
                      pathType: Prefix

In the sample configuration, a MetricsTrait is specified for the hello-helidon-component application component.

With the sample application configuration successfully deployed, you can query for metrics from the application component.

$ HOST=$(kubectl get ingress -n verrazzano-system vmi-system-prometheus -o jsonpath={.spec.rules[0].host})
$ echo $HOST

prometheus.vmi.system.default.<ip>.nip.io

$ VZPASS=$(kubectl get secret --namespace verrazzano-system verrazzano -o jsonpath={.data.password} | base64 --decode; echo)
$ curl -sk --user verrazzano:${VZPASS} -X GET https://${HOST}/api/v1/query?query=vendor_requests_count_total

{"status":"success","data":{"resultType":"vector","result":[{"metric":{"__name__":"vendor_requests_count_total","app":"hello-helidon","app_oam_dev_component":"hello-helidon-component","app_oam_dev_name":"hello-helidon-appconf","app_oam_dev_resourceType":"WORKLOAD","app_oam_dev_revision":"hello-helidon-component-v1","containerizedworkload_oam_crossplane_io":"496df78f-ef8b-4753-97fd-d9218d2f38f1","job":"hello-helidon-appconf_default_helidon-logging_hello-helidon-component","namespace":"helidon-logging","pod_name":"hello-helidon-workload-b7d9d95d8-ht7gb","pod_template_hash":"b7d9d95d8"},"value":[1616535232.487,"4800"]}]}}

MetricsTrait

Field Type Description Required
apiVersion string oam.verrazzano.io/v1alpha1 Yes
kind string MetricsTrait Yes
metadata ObjectMeta Refer to Kubernetes API documentation for fields of metadata. No
spec MetricsTraitSpec The desired state of a metrics trait. Yes

MetricsTraitSpec

MetricsTraitSpec specifies the desired state of a metrics trait.

Field Type Description Required
port integer The HTTP port for the related metrics endpoint. Defaults to 8080. No
path string The HTTP path for the related metrics endpoint. Defaults to /metrics. No
secret string The name of an opaque secret (for example, user name and password) within the workload’s namespace for metrics endpoint access. No
scraper string The Prometheus deployment used to scrape the related metrics endpoints. Defaults to verrazzano-system/vmi-system-prometheus-0. No

Last modified May 7, 2021: Rdonat/vz 2634 (#124) (e402442)