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!

naming everything hello-world is a really nice way to get stuck later — saturn
i suppose it was not actually the connection of nginx with the service but the connection of the service with the pod which failed. i think its totally irrelevant which labels you use as long as they match, — U.V.

cookandy cookandy · Accepted Answer · 2019-01-03T22:25:12

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

Kubernetes Nginx Ingress not finding service endpoint

4 Answers