Namespaces not found

Question

I see the following error when I run my deployment:

Error from server (NotFound): error when creating "n3deployment.yaml": namespaces "n2" not found

My n3deployment.yaml has no reference to n2?

Step By Step

1. Ensure everything is empty

c:\temp\k8s>kubectl get pods
No resources found.

c:\temp\k8s>kubectl get svc
No resources found.

c:\temp\k8s>kubectl get deployments
No resources found.

c:\temp\k8s>kubectl get namespaces
NAME          STATUS    AGE
default       Active    20h
docker        Active    20h
kube-public   Active    20h
kube-system   Active    20h

2. Create files

n3namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: n3

n3service.yaml
apiVersion: v1
kind: Service
metadata:
  name: my-app-n3
  namespace: n3
  labels:
    app: my-app-n3
spec:
  type: LoadBalancer
  ports:
  - name: http
    port: 80
    targetPort: http
    protocol: TCP
  selector:
    app: my-app-n3

n3deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app-n3
  labels:
    app: my-app-n3
spec:
  replicas: 1
  selector:
    matchLabels:
      app: my-app-n3
  template:
    metadata:
      labels:
        app: my-app-n3
    spec:
      containers:
      - name: waiter
        image: waiter:v1
        ports:
        - containerPort: 80

3. Apply configuration

c:\temp\k8s>kubectl apply -f n3namespace.yaml
namespace "n3" created

c:\temp\k8s>kubectl apply -f n3service.yaml
service "my-app-n3" created

c:\temp\k8s>kubectl apply -f n3deployment.yaml
Error from server (NotFound): error when creating "n3deployment.yaml": namespaces "n2" not found

I used to have a namespace called n2 but, as you can see, it no longer exists.

Fiorin

Answer 1

In my case, I was missing to have executed before:

kubectl create namespace n3

Slake

While this works, better approach is to update yaml file responsible for namespace creation. That way it is much more reproducible and ready for production use. – Binocular

Answer 2

I had previously created two contexts and my minikube cluster was set to still be in the n2 context. I deleted the context, re-ran the command and it worked.

Fiorin

Answer 3

Add namespace: n3 to deployment spec

Fard

Answer 4

In my case I created context and set --namespace to not existing one, the solution was switch namespace only using the kubectl commands:

kubectl config set-context --current --namespace=<namespace>

You can check if in your situation is the same problem using:

kubectl get svc -o wide
kubectl describe sa default | grep Namespace

Petersburg

Answer 5

I think you can use kubens and kubectx to verify on which namespace and context you are after that verify your kubernetes manifest files

Supervene

Answer 6

In your n3deployment.yaml file add namespace as well under metadata section like below

n3deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app-n3
  namespace: n3
  labels:
  app: my-app-n3
  ------
  -------

Havre