Kubernetes ud615 newbie secure-monolith.yaml `error validating data`? - kubernetes

Question

I'm a Kubernetes newbie trying to follow along with the Udacity tutorial class linked on the Kubernetes website.
I execute
kubectl create -f pods/secure-monolith.yaml
That is referencing this official yaml file: https://github.com/udacity/ud615/blob/master/kubernetes/pods/secure-monolith.yaml
I get this error:
error: error validating "pods/secure-monolith.yaml": error validating data: unknown object type schema.GroupVersionKind{Group:"", Version:"v1", Kind:"Pod"}; if you choose to ignore these errors, turn validation off with --validate=false
FYI, the official lesson link is here: https://classroom.udacity.com/courses/ud615/lessons/7824962412/concepts/81991020770923
My first guess is that the provided yaml is out of date and incompatible with the current Kubernetes. Is this right? How can I fix/update?

Answer 1

I ran into the exact same problem but with a much simpler example.
Here's my yaml:
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- image: nginx
ports:
- containerPort: 80
The command kubectl create -f pod-nginx.yaml returns:
error: error validating "pod-nginx.yaml": error validating data: unknown object type schema.GroupVersionKind{Group:"", Version:"v1", Kind:"Pod"}; if you choose to ignore these errors, turn validation off with --validate=false
As the error says, I am able to override it but I am still at a loss as to the cause of the original issue.
Local versions:
Ubuntu 16.04
minikube version: v0.22.2
kubectl version: 1.8
Thanks in advance!

Answer 2

After correct kubectl version (Same with server version), then the issue is fixed, see:
$ kubectl create -f config.yml
configmap "test-cfg" created
$ kubectl version
Client Version: version.Info{Major:"1", Minor:"7", ...
Server Version: version.Info{Major:"1", Minor:"7", ...
This is the case before modification:
$ kubectl create -f config.yml
error: error validating "config.yml": error validating data: unknown object type schema.GroupVersionKind{Group:"", Version:"v1", Kind:"ConfigMap"}; if you choose to ignore these errors, turn validation off with --validate=false
$ kubectl version
Client Version: version.Info{Major:"1", Minor:"8",...
Server Version: version.Info{Major:"1", Minor:"7",...
In general, we should used same version for kubectl and kubernetes.