error: resource mapping not found || make sure CRDs are installed first

Question

error: resource mapping not found for name: "ingress-srv" namespace: "" from "ingress-srv.yaml": no matches for kind "Ingress" in version "networking.k8s.io/v1beta1"
ensure CRDs are installed first

I am new to Kubernetes, I was setting up ingress nginx on minikube and it installed successfully but when I try to run using kubectl apply -f filename it gives above error.

here is the code filename: ingress-srv.yaml

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-srv
  annotations:
    kubernetes.io/ingress.class: nginx
spec:
  rules:
    - host: posts.com
      http:
        paths:
          - path: /posts
            pathType: Prefix
            backend:
              serviceName: posts-clusterip-srv
              servicePort: 4000

Answer 1

The resource type specified in your manifest, networking.k8s.io/v1beta1 Ingress, was removed in Kubernetes v1.22 and replaced by networking.k8s.io/v1 Ingress (see the deprecation guide for details). If your cluster's Kubernetes server version is 1.22 or higher (which I suspect it is) trying to create an Ingress resource from your manifest will result in exactly the error you're getting.

You can check your cluster's Kubernetes server version (as Kamol Hasan points out) using the command kubectl version --short.

If the version is indeed 1.22 or higher, you'll need to modify your YAML file so that its format is valid in the new version of the API. This pull request summarises the format differences. In your case, ingress-srv.yaml needs to be changed to:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-srv
  annotations:
    kubernetes.io/ingress.class: nginx
spec:
  rules:
    - host: posts.com
      http:
        paths:
          - path: /posts
            pathType: Prefix
            backend:
              service:
                name: posts-clusterip-srv
                port:
                  number: 4000