I have installed the following two different ingress controllers on my DigitalOcean managed K8S cluster:

• Nginx

• Istio

and they have been assigned to two different IP addresses. My question is, if it is wrong to have two different ingress controllers on the same K8S cluster?

The reason, why I have done it, because nginx is for tools like harbor, argocd, etc. and istio for microservices.

I have also figured out, when both are installed alongside each other, sometimes during the deployment, the K8S suddenly goes down.

For example, I have deployed:

apiVersion: v1
kind: Service
metadata:
  name: hello-kubernetes-first
  namespace: dev
spec:
  type: ClusterIP
  ports:
    - port: 80
      targetPort: 8080
  selector:
    app: hello-kubernetes-first
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-kubernetes-first
  namespace: dev
spec:
  replicas: 3
  selector:
    matchLabels:
      app: hello-kubernetes-first
  template:
    metadata:
      labels:
        app: hello-kubernetes-first
    spec:
      containers:
        - name: hello-kubernetes
          image: paulbouwer/hello-kubernetes:1.7
          ports:
            - containerPort: 8080
          env:
            - name: MESSAGE
              value: Hello from the first deployment!
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: istio
  name: helloworld-ingress
  namespace: dev
spec:
  rules:
    - host: hello.service.databaker.io
      http:
        paths:
          - path: /*
            backend:
              serviceName: hello-kubernetes-first
              servicePort: 80
---

Then I've got:

Error from server (InternalError): error when creating "istio-app.yml": Internal error occurred: failed calling webhook "validate.nginx.ingress.kubernetes.io": Post https://ingress-nginx-controller-admission.nginx.svc:443/extensions/v1beta1/ingresses?timeout=30s: dial tcp 10.245.107.175:443: i/o timeout