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