ServiceMonitor

With the Prometheus Operator, targets aren't configured by hand; a custom resource called a ServiceMonitor defines which Services are read through which port and path. The operator turns this into Prometheus configuration:

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: api
  namespace: izleme
  labels:
    release: izleme
spec:
  namespaceSelector:
    matchNames: [magaza]
  selector:
    matchLabels:
      app: api
  endpoints:
    - port: http
      path: /metrics
      interval: 30s

The Prometheus object only selects ServiceMonitors carrying certain labels; in kube-prometheus-stack the default selector is release: <release-name>. If the label is missing, the ServiceMonitor is ignored and the target doesn't appear on Prometheus's Targets page:

$ kubectl get prometheus -n izleme -o jsonpath='{.items[0].spec.serviceMonitorSelector}'
{"matchLabels":{"release":"izleme"}}
kubectl get servicemonitors -A