Kubernetes ingress gives 404 error for a particular service

Question

I have set up a kubernetes cluster on Azure with nginx ingress. I am getting a 404 error when navigating to a particular path.

I have set up some sample applications that return a simple echo that works perfectly fine. My ban api app always returns a 404 error.

When I navigate to the ingress path e.g.

http://51.145.17.105/apple

It works fine. However when I navigate to the api application, I get a 404 error using the URL:

http://51.145.17.105/ban-simple

If I log into the cluster and curl the ban-simple service (not the ingress ip) e.g.

curl -L 10.1.1.40

I get the correct response. When I try it using the nginx ingress I get the 404 error.

The ingress mapping looks right to me. Here is a copy of the ingress yaml containing the paths.

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: fruit-ingress
  namespace: ban
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
    nginx.ingress.kubernetes.io/rewrite-target: /$
spec:
  rules:
  - http:
      paths:
        - path: /apple
          backend:
            serviceName: apple-service
            servicePort: 5678
        - path: /ban-simple
          backend:
            serviceName: ban-service
            servicePort: 80

A copy of the "good" service is:

kind: Pod
apiVersion: v1
metadata:
  name: apple-app
  namespace: ban
  labels:
    app: apple
spec:
  containers:
    - name: apple-app
      image: hashicorp/http-echo
      args:
        - "-text=apple"

---

kind: Service
apiVersion: v1
metadata:
  name: apple-service
  namespace: ban
spec:
  selector:
    app: apple
  ports:
    - port: 5678 # Default port for image

The service that does not work is:

kind: Pod
apiVersion: v1
metadata:
  name: ban-simple
  namespace: ban
  labels:
    app: ban-simple
spec:
  containers:
    - name: ban-simple
      image: xxxxx.azurecr.io/services/ban

---

kind: Service
apiVersion: v1
metadata:
  name: ban-simple-service
  namespace: ban
spec:
  selector:
    app: ban-simple
  ports:
    - port: 80 # Default port for image

I have run the container locally and it works on my machine. It does redirect to localhost/index.html if that makes a difference.

Any suggestions are appreciated.

Solution 1

It was nginx.ingress.kubernetes.io/rewrite-target: /$ that was causing the issue. I commented it out and it resolved the issue.

Solution 2

As I see in your yaml file, you set the name of the service as ban-simple-service for your pod ban-simple:

kind: Service
apiVersion: v1
metadata:
  name: ban-simple-service
  namespace: ban
spec:
  selector:
    app: ban-simple
  ports:
    - port: 80 # Default port for image

But you set the service name as ban-service in the ingress:

    - path: /ban-simple
      backend:
        serviceName: ban-service
        servicePort: 80

I think it's the possible reason. So you need to change one of the service names to make them the same.

And in my opinion, I will suggest you use the deployment instead of the pod. Because if the pod is down, then it's down. But use deployment, it will recreate a new one for you. Also, I think if you expose the port in the container, the yaml file will be more readable.

Comments

[4c74356b41]

i dont understand, you app returns 404, you get a 404 and somehow you feel that something else should happen? either way, look at the ingress logs first and post them here if you cant figure it out

[Charles Xu]

Any update for the question? Does it work for you?

[IHelpPeople]

Charles, many thanks for your time. It wasn't the service name it was the ``` nginx.ingress.kubernetes.io/rewrite-target: /$ ``` causing the issue. I commented it out and it worked. Also, thanks for your suggestion on the deployment. I was just testing with the Pod. Definitely will do Deployments when the testing is complete.