Changing deprecated API versions

Updated Apr 07, 2022 ·

Overview

This scenario was encountered during CKA and CKAD exam study.

As Kubernetes evolves, some API versions become deprecated. It's important to update these to newer, supported versions to avoid issues in future updates.

Install the kubectl convert

To install the kubectl convert plugin on the control plane node, follow these steps:

1. Download the latest version:

   curl -LO https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl-convert

2. Change the file permissions and move it to /usr/local/bin/:

   chmod +x kubectl-convert
   mv kubectl-convert /usr/local/bin/

3. Use the --help option to confirm the plugin is correctly configured:

   kubectl-convert --help

Verify the Conversion

1. Example manifest with a deprecated API version:

   # ingress-old.yml
   apiVersion: networking.k8s.io/v1beta1  # Deprecated version
   kind: Ingress
   metadata:
       name: ingress-space
       annotations:
       nginx.ingress.kubernetes.io/rewrite-target: /
   spec:
       rules:
       - http:
           paths:
           - path: /video-service
           pathType: Prefix
           backend:
               serviceName: ingress-svc
               servicePort: 80

2. Use kubectl-convert to update the deprecated API version:

   kubectl-convert -f ingress-old.yaml --output-version networking.k8s.io/v1

   This will output the new file format.

   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
   annotations:
       nginx.ingress.kubernetes.io/rewrite-target: /
   creationTimestamp: null
   name: ingress-space
   spec:
   rules:
   - http:
       paths:
       - backend:
           service:
               name: ingress-svc
               port:
               number: 80
           path: /video-service
           pathType: Prefix
   status:
   loadBalancer: {} 

3. Save the converted version to a new file:

   kubectl-convert -f ingress-old.yaml --output-version networking.k8s.io/v1 > ingress-new.yaml

4. Apply the new manifest:

   kubectl apply -f ingress-new.yaml

5. Verify the changes. Check the ingress resource:

   kubectl get ing ingress-space -o yaml | grep -i apiversion