Task 4 - Deploy and Scaling Application

Objective

This task deploys an nginx application and demonstrates basic Kubernetes scaling with HPA.

The updated script keeps the original workshop flow but updates the supporting components:

Local Path Provisioner for simple lab storage
Metrics Server for HPA CPU metrics
MetalLB for LoadBalancer testing
Kong Ingress Controller for ingress testing
cert-manager for a self-signed test certificate
nginx deployment and HPA

Preflight check

This task builds on the two-node cluster from Task 3 - Install Kubernetes. Confirm that cluster is healthy and that the default namespace is still empty before you run the deploy script. From Azure Cloud Shell:

kubectl get nodes
kubectl get pods

Both nodes must report Ready:

NAME          STATUS   ROLES           AGE   VERSION
node-worker   Ready    <none>          10m   v1.30.x
node-master   Ready    control-plane   15m   v1.30.x

The default namespace should have no workloads yet. kubectl reports an empty list on stderr:

No resources found in default namespace.

If a node is missing or NotReady, go back to Task 3 and finish it before continuing.

Deploy the application and HPA demo

Run this from Azure Cloud Shell:

cd $HOME/k8s-101-workshop/terraform/
master=$(terraform output -json | jq -r .linuxvm_master_FQDN.value)
username=$(terraform output -json | jq -r .linuxvm_username.value)

scp -o 'StrictHostKeyChecking=no' $HOME/k8s-101-workshop/scripts/deploy_application_with_hpa_masternode.sh $username@$master:~/deploy_application_with_hpa_masternode.sh
ssh -o 'StrictHostKeyChecking=no' -t $username@$master "export FQDN=${master}; bash ~/deploy_application_with_hpa_masternode.sh"

Verify resources

kubectl get nodes
kubectl get pods -A
kubectl get deployment nginx-deployment
kubectl get hpa
kubectl get ingress
kubectl get svc -A

Expected nginx deployment:

NAME               READY   UP-TO-DATE   AVAILABLE
nginx-deployment   2/2     2            2

Expected HPA object:

NAME        REFERENCE                     TARGETS       MINPODS   MAXPODS   REPLICAS   AGE
nginx-hpa   Deployment/nginx-deployment   <unknown>/50%   2         10        2          34s

After Metrics Server starts collecting CPU metrics, the HPA target changes from <unknown> to a CPU percentage.

FortiAIGate readiness checks

After this task completes, run these checks before starting a FortiAIGate deployment:

kubectl cluster-info

Expected output

Kubernetes control plane is running at https://k8sXX-master.eastus.cloudapp.azure.com:6443
CoreDNS is running at https://k8sXX-master.eastus.cloudapp.azure.com:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

kubectl get nodes -o wide

NAME          STATUS   ROLES           AGE   VERSION
node-master   Ready    control-plane   53m   v1.30.14
node-worker   Ready    <none>          50m   v1.30.14

kubectl get pods -A

NAMESPACE            NAME                                       READY   STATUS    RESTARTS   AGE
calico-apiserver     calico-apiserver-66f4fd9b6d-9fcwp          1/1     Running   0          53m
calico-apiserver     calico-apiserver-66f4fd9b6d-xnb9q          1/1     Running   0          53m
calico-system        calico-kube-controllers-7677dd5467-9d2cj   1/1     Running   0          53m
calico-system        calico-node-lgddt                          1/1     Running   0          53m
calico-system        calico-node-rj584                          1/1     Running   0          51m
calico-system        calico-typha-6f4bcd7686-8lpqc              1/1     Running   0          53m
calico-system        csi-node-driver-bzl2x                      2/2     Running   0          51m
calico-system        csi-node-driver-g6k5j                      2/2     Running   0          53m
cert-manager         cert-manager-5b98df59d6-fld8m              1/1     Running   0          48m
cert-manager         cert-manager-cainjector-f48cd678-8gsrt     1/1     Running   0          48m
cert-manager         cert-manager-webhook-76cdf6c497-bzn54      1/1     Running   0          48m
default              nginx-deployment-d68499895-d4kn6           1/1     Running   0          48m
default              nginx-deployment-d68499895-tzl8x           1/1     Running   0          48m
kube-system          coredns-55cb58b774-qddlw                   1/1     Running   0          53m
kube-system          coredns-55cb58b774-zkf9k                   1/1     Running   0          53m
kube-system          etcd-node-master                           1/1     Running   0          54m
kube-system          kube-apiserver-node-master                 1/1     Running   0          54m
kube-system          kube-controller-manager-node-master        1/1     Running   0          54m
kube-system          kube-proxy-nncmh                           1/1     Running   0          51m
kube-system          kube-proxy-sg5nk                           1/1     Running   0          53m
kube-system          kube-scheduler-node-master                 1/1     Running   0          54m
kube-system          metrics-server-75778854d4-c2l97            1/1     Running   0          49m
local-path-storage   local-path-provisioner-7dd969c95d-sfkpk    1/1     Running   0          49m
metallb-system       controller-589cbf5c44-h96m8                1/1     Running   0          49m
metallb-system       speaker-glbw9                              1/1     Running   0          49m
metallb-system       speaker-nl9fc                              1/1     Running   0          49m
tigera-operator      tigera-operator-576646c5b6-6twqm           1/1     Running   0          53m

helm version
helm list

Both commands must succeed. The exact version numbers depend on the helm build installed in your environment, so do not compare them literally — what matters is that helm version prints a version.BuildInfo{...} line rather than command not found, and that helm list returns without a connection error.

helm version prints one line in this shape:

version.BuildInfo{Version:"...", GitCommit:"...", GitTreeState:"clean", GoVersion:"...", KubeClientVersion:"..."}

helm list confirms helm can reach the cluster with your kubeconfig. With no releases installed it prints only the column header and exits 0. An error mentioning the Kubernetes API server instead means your kubeconfig is not working — recheck the kubeconfig step in Task 3.

kubectl get ingressclass

Expected output — the deploy script you ran above installs the Kong Ingress Controller, so one IngressClass named kong must already exist:

NAME   CONTROLLER                            PARAMETERS   AGE
kong   ingress-controllers.konghq.com/kong   <none>       9h

The AGE column just reflects how long ago the deploy script installed Kong, so your value will differ. If this list is empty, the Kong step of the deploy script did not complete — rerun it before continuing.

kubectl get storageclass

Expected output

NAME                   PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
local-path (default)   rancher.io/local-path   Delete          WaitForFirstConsumer   false                  52m

Generate load

Run a temporary load generator from the cluster:

kubectl run -i --tty load-generator --rm --image=busybox:1.36 --restart=Never -- /bin/sh

Inside the shell, run:

while true; do wget -q -O- http://nginx-deployment.default.svc.cluster.local; done

In another terminal, watch HPA:

watch kubectl get hpa

You can also watch pods scale:

watch kubectl get pods -l app=nginx

Stop load

Press CTRL+C in the load generator shell, then type:

exit

Cleanup

kubectl delete hpa nginx-hpa --ignore-not-found
kubectl delete ingress nginx --ignore-not-found
kubectl delete deployment nginx-deployment --ignore-not-found
kubectl delete service nginx-deployment --ignore-not-found
kubectl delete pod load-generator --ignore-not-found

kubectl delete -f https://raw.githubusercontent.com/Kong/kubernetes-ingress-controller/v3.5.0/deploy/single/all-in-one-dbless.yaml --ignore-not-found
kubectl delete -f https://github.com/cert-manager/cert-manager/releases/download/v1.18.2/cert-manager.yaml --ignore-not-found
kubectl delete -f https://raw.githubusercontent.com/metallb/metallb/v0.15.2/config/manifests/metallb-native.yaml --ignore-not-found
kubectl delete -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml --ignore-not-found
kubectl delete -f https://raw.githubusercontent.com/rancher/local-path-provisioner/v0.0.31/deploy/local-path-storage.yaml --ignore-not-found

Summary

This chapter demonstrates deploying an application, exposing it through Kubernetes objects, installing Metrics Server, and using HPA to scale pods based on CPU utilization.

Review Questions

Describe how to make the client application generate more traffic.
Click for Answer…
Run a load generator pod and continuously call the nginx service.
How many minutes do you need to wait before nginx pods start increasing?
Click for Answer…
It depends on when Metrics Server reports CPU data and when HPA decides to scale. Wait a few minutes and monitor with kubectl get hpa.
How do you stop sending traffic to nginx deployment?
Click for Answer…
Stop or delete the load generator pod.