kubernetes

Kubernetes demo script

Create an AKS cluster

# Login to Azure
az login

# Create a resource group if required
az group create --location westeurope --name containers101

# Create an AKS cluster. Note this can take around ten minutes
az aks create --resource-group containers101 --name myAKSCluster --node-count 2 --generate-ssh-keys

Have a look in the Azure portal and notice that there are two new resource groups. One named 'containers101' which contains your AKS cluster and one named 'MC_containers101_myAKSCluster_westeurope' which contains the cluster nodes in a virtual machine scaleset.

Connect to your AKS cluster

az aks get-credentials --resource-group containers101 --name myAKSCluster

Look at the existing pods on AKS

kubectl get pods

Deploy a pod on AKS

kubectl apply -f pod.yaml

# List the pods
kubectl get pods

Deploy multiple pods on AKS

kubectl apply -f multiplePods.yaml

# List the pods
kubectl get pods

# List the deployments
kubectl get deployment

Container self healing

Delete original azure-vote pod

# List the pods
kubectl get pods

# Delete the original pod
kubectl delete pod azure-vote

Now list the pods again using kubectl get pods and notice that the azure-vote pod doesn't get recreated.

Delete one of the pods deployed via the deployment

kubectl delete pod azure-vote-back-6b4c4f4774-47nz2

Now list the pods again using kubectl get pods and notice you still have four pods. Notice the age of one will only be a few seconds. This is the pod that has self-healed.

Deploy service on AKS

kubectl apply -f service.yaml

# List the services
kubectl get service

Deploy the full application

First off, let's clean up everything we've added.

# Delete the service
kubectl delete service azure-vote-back
# There should only be a kubernetes service
kubectl get service

# Delete the deployment
kubectl delete deployment azure-vote-back
# There should be no pods in the default namespace
kubectl get pods

Now deploy the app in it's own namespace

# Create namespace
kubectl create namespace voting-app
# deploy app
kubectl apply -f votingApp.yaml

Have a look at the resources we have created

kubectl get all --namespace voting-app

Note you should have four pods, two services,two deployments and two replicasets.

See the application running

Find the public IP address of the front end

kubectl get service azure-vote-front --namespace voting-app

Find the external IP address browse to it in your web browser http://[EXTERNAL-IP] e.g. http://51.124.72.161

Dashboards

Browse to the kubernetes dashboard (AKS k8s version < 1.18)

# Assign permissions to the dashboard to cluster-user
kubectl create clusterrolebinding kubernetes-dashboard-cluster-user --clusterrole=cluster-admin --user=clusterUser

# Get a token from the cluster and copy to your clipboard
kubectl config view

# Open a proxy to the Kubernetes API
az aks browse --resource-group containers101 --name myAKSCluster

If you don't see the dashboard, browse directly to the API http://127.0.0.1:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy
Select Token and paste in the value from `kubectl config view'. Choose Sign in.

You can also view the kubernetes resources via the Azure portal

Clean up resources

To avoid Azure charges, you should clean up unneeded resources. When the cluster is no longer needed, use the az group delete command to remove the resource group, container service, and all related resources.

az group delete --name containers101 --yes --no-wait