K8S 裸机 nginx-ingress-controller

Question

OS: RHEL7 | k8s version: 1.12/13 | kubespray | baremetal

I have a standard kubespray bare metal cluster deployed and I am trying to understand what is the simplest recommended way to deploy nginx-ingress-controller that will allow me to deploy simple services. There is no load balancer provided. I want my MASTER public IP as the endpoint for my services.

Github k8s ingress-nginx suggests NodePort service as a "mandatory" step, which seems not to be enough to make it works along with kubespray's ingress_controller .

I was able to make it working forcing LoadBalancer service type and setting externalIP value as a MASTER public IP into nginx-ingress-controller via kubectl edit svc but it seems not to be a correct solution due to lack of a load balancer itself.

Similar results using helm chart:

helm install -n ingress-nginx stable/nginx-ingress --set controller.service.externalIPs[0]="MASTER PUBLIC IP"

Answer 1

I was able to make it working forcing LoadBalancer service type and setting externalIP value as a MASTER public IP into nginx-ingress-controller via kubectl edit svc but it seems not to be a correct solution due to lack of a load balancer itself.

Correct, that is not what LoadBalancer is intended for. It's intended for provisioning load balancers with cloud providers like AWS, GCP, or Azure, or a load balancer that has some sort of API so that the kube-controller-manager can interface with it. If you look at your kube-controller-manager logs you should see some errors. The way you made it work it's obviously a hack, but I suppose it works.

The standard way to implement this is just to use a NodePort service and have whatever proxy/load balancer (ie nginx, or haproxy) on your master to send traffic to the NodePorts. Note that I don't recommend the master to front your services either since it already handles some of the critical Kubernetes pods like the kube-controller-manager, kube-apiserver, kube-scheduler, etc.

The only exception is MetalLB which you can use with a LoadBalancer service type. Keep in mind that as of this writing the project is in its early stages.