My letsencrypt order keeps pending. I am using cert-manager on my single node kubernetes plane. Also I am using letsencrypt.

kind: Certificate
metadata:
  name: example-zone
  namespace: default
spec:
  secretName: example-zone-tls
  renewBefore: 360h # 15d
  commonName: example.zone
  dnsNames:
    - example.zone
  issuerRef:
    name: letsencrypt-prod
    kind: ClusterIssuer

Output:

pascal$ kubectl get cert,order
NAME                                          READY   SECRET             AGE
certificate.certmanager.k8s.io/example-zone   False   example-zone-tls   79m

NAME                                               STATE     AGE
order.certmanager.k8s.io/example-zone-2971070786   pending   77m

Events received:

Events:
  Type     Reason            Age   From          Message
  ----     ------            ----  ----          -------
  Warning  NoMatchingSolver  15s   cert-manager  Failed to create challenge for domain "example.zone": no configured challenge solvers can be used for this challenge

The cert should be issued but I think it hangs up in my haproxy. No errors and I don't exactly know how to expose the acme challenge using haproxy, could someone explain me?

My ClusterIssuer:

pascal$ kubectl describe clusterissuer letsencrypt-prod
Name:         letsencrypt-prod
Namespace:    # yep, it's empty!?
Labels:       <none>
API Version:  certmanager.k8s.io/v1alpha1
Kind:         ClusterIssuer
Spec:
  Acme:
    Email:  <my-real-mail>
    Http 01:
      Ingress Class:  haproxy
    Private Key Secret Ref:
      Name:  letsencrypt-prod
    Server:  https://acme-v02.api.letsencrypt.org/directory
Status:
  Acme:
    Last Registered Email:  <my-real-mail>
    Uri:                    https://acme-v02.api.letsencrypt.org/acme/acct/<hash>
  Conditions:
    Last Transition Time:  2019-08-17T11:49:05Z
    Message:               The ACME account was registered with the ACME server
    Reason:                ACMEAccountRegistered
    Status:                True
    Type:                  Ready
Events:                    <none>