In my gcloud console it shows the following error for my defined ingresses:
Error during sync: error while evaluating the ingress spec: service "monitoring/kube-prometheus" is type "ClusterIP", expected "NodePort" or "LoadBalancer"
I am using traefik as reverse proxy (instead of nginx) and therefore I define an ingress using a ClusterIP. As far as I understand the process all traffic is proxied through the traefik service (which has a Loadbalancer ingress defined) and therefore all my other ingresses SHOULD actually have a ClusterIP instead of NodePort or Loadbalancer?
Question:
So why does Google Cloud warn me that it expected a NodePort or LoadBalancer?
Thanks @aayore. In my case, I had to specify an ingress class explicitly, so that Google Cloud wouldn't interfere. The Nginx ingress seems to be happy with ClusterIp
services.
metadata:
name: foo
annotations:
kubernetes.io/ingress.class: "nginx"
I don't know why that error happens, because it seems (to me) to be a valid configuration. But to clear the error, you can switch your service to a named NodePort. Then switch your ingress to use the port name instead of the number. For example:
Service:
apiVersion: v1
kind: Service
metadata:
name: testapp
spec:
ports:
- name: testapp-http # ADD THIS
port: 80
protocol: TCP
targetPort: 80
selector:
app: testapp
type: NodePort
Ingress:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: testapp
spec:
rules:
- host: hostname.goes.here
http:
paths:
- backend:
serviceName: testapp
# USE THE PORT NAME FROM THE SERVICE INSTEAD OF THE PORT NUMBER
servicePort: testapp-http
path: /
Update:
This is the explanation I received from Google.
Since services by default are ClusterIP [1] and this type of service is meant to be accessible from inside the cluster. It can be accessed from outside when kube-proxy is used, not meant to be directly accessed with an ingress.
As a suggestion, I personally find this article [2] good for understanding the difference between these types of services.
[1] https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types