all-in-one-webhook.yaml

apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: jenkins-webhook-certificate
  namespace: default
spec:
  duration: 2160h 
  renewBefore: 360h
  secretName: jenkins-webhook-certificate
  dnsNames:
  - jenkins-webhook-service.default.svc
  - jenkins-webhook-service.default.svc.cluster.local
  issuerRef:
    kind: Issuer
    name: selfsigned
---
apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
  name: selfsigned
  namespace: default
spec:
  selfSigned: {}
---
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:
  name: jenkins-webhook
  annotations:
    cert-manager.io/inject-ca-from: default/jenkins-webhook-certificate
webhooks:
- admissionReviewVersions:
  - v1
  - v1beta1
  clientConfig:
    service:
      name: jenkins-webhook-service
      namespace: default
      path: /validate-jenkins-io-v1alpha2-jenkins
  failurePolicy: Fail
  name: vjenkins.kb.io
  timeoutSeconds: 30
  rules:
  - apiGroups:
    - jenkins.io
    apiVersions:
    - v1alpha2
    operations:
    - CREATE
    - UPDATE
    resources:
    - jenkins
    scope: "Namespaced"
  sideEffects: None
---
apiVersion: v1
kind: Service
metadata:
  name: jenkins-webhook-service
  namespace: default
spec:
  ports:
    - port: 443
      targetPort: 9443
  selector:
    control-plane: controller-manager
---