The default certificates used by the ingress operator are self-signed i.e. by an internal CA. I thought it was a better idea to generate my own certs using cert-manager so here is what I did:

  1. Generate a certificate:

    apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: internal-nanibot-net-cert
  namespace: openshift-ingress
spec:
  secretName: internal-nanibot-net-cert-secret
  duration: 2160h
  renewBefore: 360h
  isCA: false
  privateKey:
    algorithm: RSA
    encoding: PKCS1
    size: 2048
  usages:
    - server auth
    - client auth
  dnsNames:
    - "*.apps.openshift.internal.nanibot.net"
  issuerRef:
    name: nanibot-net-issuer
    kind: ClusterIssuer

  2. Patch the default ingresscontroller.operator resource to reference the secret where the tls data is stored:

    oc patch ingresscontroller.operator default \
     --type=merge -p \
     '{"spec":{"defaultCertificate": {"name": "internal-nanibot-net-cert-secret"}}}' \
     -n openshift-ingress-operator