#Add repo ingress-nginx
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx 
helm repo update ingress-nginx

#Install ingress nginx
helm install ingress-nginx ingress-nginx/ingress-nginx \
		--namespace ingress-nginx \
		--set controller.service.appProtocol=false \
		--create-namespace

kubectl get all -n ingress-nginx

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: demoapp-pvc
  namespace: demoapp
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: default-storage-class-1 #adjust to use your storage class

apiVersion: apps/v1
kind: Deployment
metadata:
  name: demoapp
  namespace: demoapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: demoapp
  template:
    metadata:
      labels:
        app: demoapp
    spec:
      containers:
      - name: demoapp
        image: paulbouwer/hello-kubernetes:1.8
        ports:
        - containerPort: 8080
        volumeMounts:
        - mountPath: /data
          name: demoapp-storage
      volumes:
      - name: demoapp-storage
        persistentVolumeClaim:
          claimName: demoapp-pvc

apiVersion: v1
kind: Service
metadata:
  name: demoapp
  namespace: demoapp
spec:
  type: ClusterIP
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: demoapp

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: demoapp-ingress
  namespace: demoapp
spec:
  ingressClassName: nginx
  rules:
  - host: demoapp.cloud.net.vn #adjust to use your domain
    http:
      paths:
      - backend:
          service:
            name: demoapp
            port:
              number: 80
        path: /
        pathType: Prefix

cd demoapp
kubectl apply -f .

Name: <ingress-host>
Address: 42.113.xx.xx  (EXTERNAL-IP của ingress nginx)

df -h

echo 1 > /sys/block/sda/device/rescan 
growpart /dev/sda 4 
resize2fs /dev/sda4

fdisk -l

#Install tanzu-cli to ubuntu
sudo apt update
sudo apt install -y ca-certificates curl gpg
sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://storage.googleapis.com/tanzu-cli-installer-packages/keys/TANZU-PACKAGING-GPG-RSA-KEY.gpg | sudo gpg --dearmor -o /etc/apt/keyrings/tanzu-archive-keyring.gpg
echo "deb [signed-by=/etc/apt/keyrings/tanzu-archive-keyring.gpg] https://storage.googleapis.com/tanzu-cli-installer-packages/apt tanzu-cli-jessie main" | sudo tee /etc/apt/sources.list.d/tanzu.list
sudo apt update
sudo apt install -y tanzu-cli
#Verify tanzu-cli installation
tanzu version

kubectl config use-context <your context name>

tanzu package available list cluster-autoscaler.tanzu.vmware.com

kubectl create secret generic cluster-autoscaler-mgmt-config-secret \
--from-file=value=<path to your kubeconfig file> \
-n kube-system

arguments:
  ignoreDaemonsetsUtilization: true
  maxNodeProvisionTime: 15m
  maxNodesTotal: 0 #Leave this value as 0. We will define the max and min number of nodes later.
  metricsPort: 8085
  scaleDownDelayAfterAdd: 10m
  scaleDownDelayAfterDelete: 10s
  scaleDownDelayAfterFailure: 3m
  scaleDownUnneededTime: 10m
clusterConfig:
  clusterName: "demo-autoscale-tkg" #adjust here
  clusterNamespace: "demo-autoscale-tkg-ns" #adjust here
paused: false

tanzu package install cluster-autoscaler \
--package cluster-autoscaler.tanzu.vmware.com \
--version <version available> \ #adjust the version listed above to match your kubernetes version
--values-file 'cluster-autoscaler-values.yaml' \
--namespace tkg-system #please do not change, this is default namespace for tanzu package

kubectl get machinedeployments.cluster.x-k8s.io -A

kubectl annotate machinedeployment <machinedeployment name> cluster.x-k8s.io/cluster-api-autoscaler-node-group-min-size=<number min> -n <machinedeployment namespace>
kubectl annotate machinedeployment <machinedeployment name> cluster.x-k8s.io/cluster-api-autoscaler-node-group-max-size=<number max> -n <machinedeployment namespace>

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  namespace: default
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
      topologySpreadConstraints: #Spreads pods across different nodes (ensures no node has more pods than others)
      - maxSkew: 1 
        topologyKey: kubernetes.io/hostname
        whenUnsatisfiable: DoNotSchedule
        labelSelector:
          matchLabels:
            app: nginx

kubectl apply -f test-autoscale.yaml

kubectl get pods

kubectl describe pod nginx-589656b9b5-mcm5j | grep -A 10 Events

Warning  FailedScheduling  2m53s  default-scheduler   0/2 nodes are available: 1 node(s) didn't match pod topology spread constraints, 1 node(s) had untolerated taint {node-role.kubernetes.io/control-plane: }. preemption: 0/2 nodes are available: 1 No preemption victims found for incoming pod, 1 Preemption is not helpful for scheduling.
Normal   TriggeredScaleUp  2m43s  cluster-autoscaler  pod triggered scale-up: [{MachineDeployment/demo-autoscale-tkg-ns/demo-autoscale-tkg-worker-node-pool-1 1->2 (max: 5)}]

kubectl delete -f test-autoscale.yaml