Deploy ingress nginx with a domain in kubernetes - kubernetes

Question

I have deployed airflow in kubernetes as is descrived in this link: https://github.com/apache/airflow/tree/master/chart
To access the airflow UI I can do:
kubectl port-forward svc/airflow2-webserver 8080:8080 --namespace default
But I would want to expose it in a url. I found this guide:
https://godatadriven.com/blog/deploying-apache-airflow-on-azure-kubernetes-service/
In the bottom part: FQDN with Ingress controller, he installs an nginx-ingress-controller and a cert manager.
Then I create a Cluster-issuer:
apiVersion: cert-manager.io/v1alpha2
kind: ClusterIssuer
metadata:
name: letsencrypt-staging
spec:
acme:
server: https://acme-staging-v02.api.letsencrypt.org/directory
email: my-email#gmail.com
privateKeySecretRef:
name: letsencrypt-staging
solvers:
- http01:
ingress:
class: nginx
podTemplate:
spec:
nodeSelector:
"kubernetes.io/os": linux
I install the ingress-routes.yml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: airflow-ingress
namespace: default
annotations:
kubernetes.io/ingress.class: nginx
certmanager.k8s.io/cluster-issuer: letsencrypt-staging
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
tls:
- hosts:
- mydomain.westeurope.cloudapp.azure.com
secretName: tls-secret-test2
rules:
- host: mydomain.westeurope.cloudapp.azure.com
http:
paths:
- path: /
backend:
serviceName: airflow2-webserver
servicePort: 8080
But when I try to get my certificate:
kubectl describe certificate
No resources found in default namespace.
I have deployed everything but I don´t know what is missing but when I go to my domain is still not trusted

Answer 1

It looks like your DNS A record is not pointing to your Ingress LoadBalancer public IP. Thus your cert-manager issuer is not able to validate your domain ownership from outside using http challange.
To verify you can use tool called MXToolBox. In your configuration (https://mxtoolbox.com/SuperTool.aspx?action=a%3amydomain.westeurope.cloudapp.azure.com&run=toolpage) it's pointing to private IP.
Solution
To resolve this issue, you should Add an A record to your DNS zone
az network dns record-set a add-record \
--resource-group myResourceGroup \
--zone-name MY_CUSTOM_DOMAIN \
--record-set-name '*' \
--ipv4-address MY_EXTERNAL_IP