Single NGINX-Ingress Controller for subdomains that have resources in separate namespaces

Question

Can anyone explain to me how to set up a SINGLE nginx ingress controller with configuration that I currently have, as follows:

• A.MY-SITE.COM = Service, Ingress, Pods..etc live under the "A" namespace
• B.MY-SITE.COM = Service, Ingress, Pods..etc live under the "B" namepsace

I've seen here

https://github.com/nginxinc/kubernetes-ingress/tree/v1.7.0/examples-of-custom-resources/cross-namespace-configuration

This seems to be on the right track, but it's for paths "/cafe". When I need it to be "a.my-site.com".

The main reason I want to do this is I don't want to have to install an ingress controller for every client (namespace) we have.

Answer 1

So I figured this out, The default HELM nginx-ingress controller installation works fine without SSL certificates. NGINX Controller actually does work with ingress resources from various namespaces.

I installed my *.domain.com certificate and key using

kubectl create secret tls {SECRET_NAME} --key {KEY_FILE} --cert {CERT_FILE}

Then in the nginx-ingress-controller deployment I added:

-args:
 - --default-ssl-certificate=tenancy/whatevername-wildcard={NAMESPACE}/{SECRET_NAME}

The ingresses live in the namespace. For example:

Namespace A: Ingress -> Host: a.domain.com

Namespace B: Ingress with host: b.domain.com

the only thing listed in the annotations for the ingress controllers is kubernetes.io/ingress.class: "nginx"

All domains points to the nginx load balancer IP.

Now it works perfectly. Very simple, but it was also very unclear scouring through the docs.