Kubernetes Nginx Ingress not finding service endpoint

Question

I'm having some trouble getting the Nginx ingress controller working in my Kubernetes cluster. I have created the nginx-ingress deployments, services, roles, etc., according to https://kubernetes.github.io/ingress-nginx/deploy/

I also deployed a simple hello-world app which listens on port 8080

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: hello-world
  namespace: default
spec:
  selector:
    matchLabels:
      name: hello-world
  template:
    metadata:
      labels:
        name: hello-world
    spec:
      containers:
      - name: hello-world
        image: myrepo/hello-world
        resources:
          requests:
            memory: 200Mi
            cpu: 150m
          limits:
            cpu: 300m
        ports:
          - name: http
            containerPort: 8080
            protocol: TCP

And created a service for it

kind: Service
apiVersion: v1
metadata:
  namespace: default
  name: hello-world
spec:
  selector:
    app: hello-world
  ports:
    - name: server
      port: 8080

Finally, I created a TLS secret (my-tls-secret) and deployed the nginx ingress per the instructions. For example:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
  name: hello-world
  namespace: default
spec:
  rules:
    - host: hello-world.mydomain.com
      http:
        paths:
        - path: /
          backend:
            serviceName: hello-world
            servicePort: server
  tls:
      - hosts:
          - hello-world.mydomain.com
        secretName: my-tls-cert

However, I am unable to ever reach my application, and in the logs I see

W0103 19:11:15.712062       6 controller.go:826] Service "default/hello-world" does not have any active Endpoint.
I0103 19:11:15.712254       6 controller.go:172] Configuration changes detected, backend reload required.
I0103 19:11:15.864774       6 controller.go:190] Backend successfully reloaded.

I am not sure why it says Service "default/hello-world" does not have any active Endpoint. I have used a similar service definition for the traefik ingress controller without any issues.

I'm hoping I'm missing something obvious with the nginx ingress. Any help you can provide would be appreciated!

Answer 1

I discovered what I was doing wrong. In my application definition I was using name as my selector

  selector:
    matchLabels:
      name: hello-world
  template:
    metadata:
      labels:
        name: hello-world

Whereas in my service I was using app

  selector:
    app: hello-world

After updating my service to use app, it worked

  selector:
    matchLabels:
      app: hello-world
  template:
    metadata:
      labels:
        app: hello-world