Red Hat OpenShift Container Platform

Configuring metrics collection for cert-manager Operator for Red Hat OpenShift operands by using a ServiceMonitor

You can configure metrics collection for the cert-manager Operator for Red Hat OpenShift operands by creating a ServiceMonitor custom resource (CR).

The cert-manager Operator for Red Hat OpenShift operands expose metrics by default on port 9402 at the /metrics service endpoint. The ServiceMonitor CR enables Prometheus Operator to collect custom metrics.

Prerequisites

You have access to the cluster as a user with the cluster-admin role.
You have installed the cert-manager Operator for Red Hat OpenShift.
You have enabled the user workload monitoring.

Procedure

Create the ServiceMonitor CR:

Create the YAML file that defines the ServiceMonitor CR:

Example servicemonitor-cert-manager.yaml file

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  labels:
    app: cert-manager
    app.kubernetes.io/instance: cert-manager
    app.kubernetes.io/name: cert-manager
  name: cert-manager
  namespace: cert-manager
spec:
  endpoints:
    - honorLabels: false
      interval: 60s
      path: /metrics
      scrapeTimeout: 30s
      targetPort: 9402
  selector:
    matchExpressions:
      - key: app.kubernetes.io/name
        operator: In
        values:
          - cainjector
          - cert-manager
          - webhook
      - key: app.kubernetes.io/instance
        operator: In
        values:
          - cert-manager
      - key: app.kubernetes.io/component
        operator: In
        values:
          - cainjector
          - controller
          - webhook

Create the ServiceMonitor CR by running the following command:
```
$ oc apply -f servicemonitor-cert-manager.yaml
```
After the ServiceMonitor CR is created, the user workload Prometheus instance begins metrics collection from the cert-manager Operator for Red Hat OpenShift operands. The collected metrics are labeled with job="cert-manager",job="cert-manager-cainjector", and job="cert-manager-webhook".

Verification

In the Red Hat OpenShift Container Platform web console, navigate to Observe → Targets.
In the Label filter field, enter the following labels to filter the metrics targets for each operand:
```
$ service=cert-manager
```
```
$ service=cert-manager-webhook
```
```
$ service=cert-manager-cainjector
```
Confirm that the Status column shows Up for the cert-manager, cert-manager-webhook, and cert-manager-cainjector entries.