如何使用 `service.spec.externalIPs` 而不是 `--type=LoadBalancer` 在 AWS 上公开 Kubernetes 服务？

Question

I've deployed a Kubernetes cluster on AWS using kops and I'm able to expose my pods using a service with --type=LoadBalancer :

kubectl run sample-nginx --image=nginx --replicas=2 --port=80
kubectl expose deployment sample-nginx --port=80 --type=LoadBalancer

However, I cannot get it to work by specifying service.spec.externalIPs with the public IP of my master node.

I've allowed ingress traffic the specified port and used https://kubernetes.io/docs/concepts/services-networking/service/#external-ips as documentation.

Can anyone clarify how to expose a service on AWS without using the cloud provider's native load balancer?

Answer 1

If you want to avoid using Loadbalancer then you case use NodePort type of service.

NodePort exposes service on each Node's IP at a static port (the NodePort ). ClusterIP service that NodePort service routes is created along. You will be able to reach the NodePort service, from outside by requesting:

<NodeIP>:<NodePort> 

That means that if you access any node with that port you will be able to reach your service. It worth to remember that NodePorts are high-numbered ports (30 000 - 32767)

Coming back specifically to AWS here is theirs official document how to expose a services along with NodePort explained.

Do note very important inforamation there about enabling the ports:

Note: Before you access NodeIP:NodePort from an outside cluster, you must enable the security group of the nodes to allow incoming traffic through your service port.

Let me know if this helps.