cert-manager.yaml

apiVersion: cert-manager.io/v1alpha3
kind: ClusterIssuer
metadata:
  name: letsencrypt-prod
spec:
  acme:
    server: https://acme-v02.api.letsencrypt.org/directory
    email: user@contoso.com
    privateKeySecretRef:
      name: letsencrypt-prod
    solvers:
    - http01:
        ingress:
          class: nginx
---
apiVersion: cert-manager.io/v1alpha3
kind: ClusterIssuer
metadata:
  name: letsencrypt-staging
spec:
  acme:
    server: https://acme-staging-v02.api.letsencrypt.org/directory
    email: user@contoso.com
    privateKeySecretRef:
      name: letsencrypt-staging
    solvers:
    - http01:
        ingress:
          class: nginx
---
apiVersion: cert-manager.io/v1alpha3
kind: Certificate
metadata:
  name: $DEFAULT_CERT_SECRET_NAME
spec:
  secretName: $DEFAULT_CERT_SECRET_NAME
  dnsNames:
  - $FQDN
  issuerRef:
    name: letsencrypt-staging
    kind: ClusterIssuer