Enable generic metric scraping¶

StackLight can scrape metrics from any service that exposes Prometheus metrics and is running on the Kubernetes cluster. Such metrics appear in Prometheus under the {job="stacklight-generic",service="<service_name>",namespace="<service_namespace>"} set of labels. If the Kubernetes service is backed by Kubernetes pods, the set of labels also includes {pod="<pod_name>"}.

To enable the functionality, define at least one of the following annotations in the service metadata:

"generic.stacklight.mirantis.com/scrape-port" - the HTTP endpoint port. By default, the port number found through Kubernetes service discovery, usually __meta_kubernetes_pod_container_port_number. If none discovered, use the default port for the chosen scheme.
"generic.stacklight.mirantis.com/scrape-path" - the HTTP endpoint path, related to the Prometheus scrape_config.metrics_path option. By default, /metrics.
"generic.stacklight.mirantis.com/scrape-scheme" - the HTTP endpoint scheme between HTTP and HTTPS, related to the Prometheus scrape_config.scheme option. By default, http.

For example:

metadata:
  annotations:
    "generic.stacklight.mirantis.com/scrape-path": "/metrics"

metadata:
  annotations:
    "generic.stacklight.mirantis.com/scrape-port": "8080"