CODEWITHSUNDEEP
kuberneteskubernetes-ingressamazon-eksaws-load-balancer-controller
Hunter Carnes
Hunter Carnes

Reputation: 1

K8s FQDN EndpointSlice not recognized by ingress?

Needing ingress -> service (no label selectors) -> service (with label selectors) -> pods...

Setting up a blue/green environment and due to cross-app restrictions, I need an ingress sending traffic to a service which forwards traffic to another service name, which may frequently change (so I'm trying to avoid hardcoding any IP addresses) and will also need to support services in another namespace, and later, in another cluster altogether. I'm reading that I may need to manually create my own EndpointSlice for the ExternalName type service to be used by the ingress BUT I am using the aws alb controller for ALB creation using the ingress annotations and apparently it doesn't support ExternalName services. My ingress is giving an endpoints not found error even after creating an endpointslice with FQDN type, regardless of if the live-svc below is of ExternalName type or not.

Important: The service the external ingress sends traffic to needs to receive traffic from other pods internally when referenced by its internal DNS name live-svc.myNamespace.svc.cluster.local. Traffic can't exit the cluster and come back in for inter-app communication, due to latency requirements. So, users could access pods by going to app-live.mydomain.com, OR other apps within the cluster could reference the live-svc DNS name to access and traffic stays internal to the cluster.

Below is what I'm trying. The ingress should reach live-svc which then directs traffic to secondaryService which directs traffic to pods based on label selectors. I think the EndpointSlice is what is causing it to not work. Do I have to create an Endpoints type resource, instead? I thought EndpointSlice is replacing Endpoints and is recommended?

apiVersion: v1
kind: Service
metadata:
  name: live-svc
  namespace: myNamespace
spec:
  #type: ExternalName
  #externalName: secondaryService.myNamespace.svc.cluster.local #this secondary service does select pods successfully
  ports:
  - name: https
    port: 443
    protocol: TCP
    targetPort: https

apiVersion: discovery.k8s.io/v1
kind: EndpointSlice
metadata:
  name: live-svc
  namespace: myNamespace
  labels:
    kubernetes.io/service-name: live-svc
addressType: FQDN
ports:
  - name: https
    protocol: TCP
    port: 443
endpoints:
  - addresses:
      - secondaryService.myNamespace.svc.cluster.local

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    ...
  name: app-public
  namespace: myNamespace
spec:
  rules:
  - host: app-live.mydomain.com
    http:
      paths:
      - backend:
          service:
            name: live-svc
            port:
              name: https
        path: /
        pathType: Prefix

Upvotes: 0

Views: 439

Answers (1)

gohm'c
gohm'c

Reputation: 15558

...secondaryService which directs traffic to pods based on label selectors. 
...
endpoints:
  - addresses:
      - secondaryService.myNamespace.svc.cluster.local

The FQDN cannot be K8s service type ClusterIP, this is not supported.

Upvotes: 0

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