Kubernetes nginx ingress 0.22 not respecting cookie affinity annotation? - kubernetes

Question

We recently upgraded to nginx-ingress 0.22. Before this upgrade, my service was using the old namespace ingress.kubernetes.io/affinity: cookie and everything was working as I expected. However, upon the upgrade to 0.22, affinity stopped being applied to my service (I don't see sticky anywhere in the nginx.conf).
I looked at the docs and changed the namespace to nginx.ingress.kubernetes.io as shown in this example, but it didn't help.
Is there some debug log I can look at that will show the configuration parsing/building process? My guess is that some other setting is preventing this from working (I can't imagine the k8s team shipped a release with this feature completely broken), but I'm not sure what that could be.
My ingress config as shown by the k8s dashboard follows:
"kind": "Ingress",
"apiVersion": "extensions/v1beta1",
"metadata": {
"name": "example-ingress",
"namespace": "master",
"selfLink": "/apis/extensions/v1beta1/namespaces/master/ingresses/example-ingress",
"uid": "01e81627-3b90-11e9-bb5a-f6bc944a4132",
"resourceVersion": "23345275",
"generation": 1,
"creationTimestamp": "2019-02-28T19:35:30Z",
"labels": {
},
"annotations": {
"ingress.kubernetes.io/backend-protocol": "HTTPS",
"ingress.kubernetes.io/limit-rps": "100",
"ingress.kubernetes.io/proxy-body-size": "100m",
"ingress.kubernetes.io/proxy-read-timeout": "60",
"ingress.kubernetes.io/proxy-send-timeout": "60",
"ingress.kubernetes.io/secure-backends": "true",
"ingress.kubernetes.io/secure-verify-ca-secret": "example-ingress-ssl",
"kubernetes.io/ingress.class": "nginx",
"nginx.ingress.kubernetes.io/affinity": "cookie",
"nginx.ingress.kubernetes.io/backend-protocol": "HTTPS",
"nginx.ingress.kubernetes.io/limit-rps": "100",
"nginx.ingress.kubernetes.io/proxy-body-size": "100m",
"nginx.ingress.kubernetes.io/proxy-buffer-size": "8k",
"nginx.ingress.kubernetes.io/proxy-read-timeout": "60",
"nginx.ingress.kubernetes.io/proxy-send-timeout": "60",
"nginx.ingress.kubernetes.io/secure-verify-ca-secret": "example-ingress-ssl",
"nginx.ingress.kubernetes.io/session-cookie-expires": "172800",
"nginx.ingress.kubernetes.io/session-cookie-max-age": "172800",
"nginx.ingress.kubernetes.io/session-cookie-name": "route",
"nginx.org/websocket-services": "example"
}
},
"spec": {
"tls": [
{
"hosts": [
"*.example.net"
],
"secretName": "example-ingress-ssl"
}
],
"rules": [
{
"host": "*.example.net",
"http": {
"paths": [
{
"path": "/",
"backend": {
"serviceName": "example",
"servicePort": 443
}
}
]
}
}
]
},
"status": {
"loadBalancer": {
"ingress": [
{}
]
}
}
}

Answer 1

As I tested Sticky session affinity with Nginx Ingress version 0.22, I can assure that it works just fine. Then when I was looking for your configuration, I replaced wildcard host host: "*.example.net" with i.e host: "stickyingress.example.net" just to ignore wildcard, and it worked fine again.
So after some search I found out that from this issue
Wildcard hostnames are not supported by the Ingress spec (only SSL
wildcard certificates are)
Even this issue was opened for NGINX Ingress controller version:
0.21.0