exam-3

Q01:
kubectl create sa pvviewer
kubectl create clusterrole pvviewer-role --resource=persistentvolumes --verb=list
kubectl create clusterrolebinding pvviewer-role-binding --clusterrole=pvviewer-role --serviceaccount=default:pvviewer
kubectl run --generator=run-pod/v1 pvviewer --image=redis --dry-run  -o yaml > pvviewer.yaml
#Add serviceAccountName: pvviewer

apiVersion: v1
kind: Pod
metadata:
  name: pvviewer
spec:
  containers:
  - image: redis
    imagePullPolicy: IfNotPresent
    name: pvviewer
  serviceAccountName: pvviewer  
    
    
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Q02:
kubectl get nodes -o jsonpath='{.items[*].status.addresses[?(@.type=="InternalIP")].address}' > /root/node_ips OR
kubectl get nodes -o jsonpath='{.items[*].status.addresses[].address}' > /root/node_ips
    
Refer: https://kubernetes.io/docs/reference/kubectl/cheatsheet/
    
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Q03:
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  name: multi-pod
spec:
  containers:
  - image: nginx
    name: alpha
    env:
    - name: name
      value: alpha
  - image: busybox
    name: beta
    command: ["sleep", "4800"]
    env:
    - name: name
      value: beta
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Q04
apiVersion: v1kind: Pod
metadata:
  name: lion
spec:
  containers:
  - image: redis:alpine
    name: lion    resources:
      limits:
        cpu: "2"        memory: "500Mi"
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Q05
kubectl run --generator=run-pod/v1 test-nc  --image=busybox:1.28 --rm -it -- nc -z -v -w2 np-test-service 80
#The above command should time out
      
#Now Create a network Policy allowing connections from All to port 80 to pod np-test-1 (use label: run=np-test-1)
      
apiVersion: extensions/v1beta1
kind: NetworkPolicy
metadata:
  generation: 1
  name: ingress-to-nptest
spec:
  podSelector:
    matchLabels:
      run: np-test-1
  policyTypes:
  - Ingress
  ingress:
  - ports:
    - port: 80
      protocol: TCP
      
#Check connectivity Again:
   
master $ kubectl run --generator=run-pod/v1 test-nc  --image=busybox:1.28 --rm -it -- sh
If you don't see a command prompt, try pressing enter.
/ # nc -z -v -w 2 np-test-service 80
np-test-service (10.110.179.146:80) open
/ # ^C
/ # Session ended, resume using 'kubectl attach test-nc -c test-nc -i -t' command when the pod is running
pod "test-nc" deleted
master $ 
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Q06
kubectl taint  node node01 env_type=production:NoSchedule
master $ kubectl describe node node01 | grep -i  taint
Taints:             env_type=production:NoSchedule
master $

kubectl run --generator=run-pod/v1 dev-redis --image=redis:alpine

#Check that the pod is not scheduled on node01

#Create prod-redis pod with toleration
apiVersion: v1
kind: Pod
metadata:
  name: prod-redis
  namespace: default
spec:
  containers:  - image: redis:alpine
    name: prod-redis
  tolerations:
  - effect: NoSchedule
    key: env_type
    value: production
    operator: Equal
 
kubectl create -f prod-redis.yaml

#Check that the pod is running. Pod can be scheduled on node01 but it is not necessary that the scheduler will exclusively place it 
on node01. Since there is no node affinity specified, the scheduler can place it on any node. 
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