Knowledge: Kubernetes part5

Kubernetes part5

Class 89th Kubernetes Part5 August 15th

Step1: Install Kops

[root@ip-10-0-0-22 ~]# curl -Lo kops https://github.com/kubernetes/kops/releases/download/$(curl -s https://api.github.com/repos/kubernetes/kops/releases/latest | grep tag_name | cut -d '"' -f 4)/kops-linux-amd64

Install kubectl

[root@ip-10-0-0-22 ~]# kubectl version
Client Version: v1.33.4
Kustomize Version: v5.6.0
The connection to the server localhost:8080 was refused - did you specify the right host or port?

[root@ip-10-0-0-22 ~]# aws s3 ls

2025-08-16 16:58:08 ccitpublicbucket16

[root@ip-10-0-0-22 ~]# export KOPS_STATE_STORE=s3://ccitpublicbucket16

Step2: Create the cluster

[root@ip-10-0-0-22 ~]# kops create cluster --name kopsclstr.k8s.local --zones eu-west-2b,eu-west-2a --master-count 1 --master-size c7i-flex.large --master-volume-size 20 --node-count 2 --node-size t3.micro --node-volume-size=15 --image=ami-044415bb13eee2391

[root@ip-10-0-0-22 ~]#kops update cluster --name kopsclstr.k8s.local --yes --admin

Step3: Deployment file create for manifest,

[root@ip-10-0-0-22 ~]# cat manifest.yaml

---

apiVersion: apps/v1

kind: Deployment

metadata:

spec:

replicas: 2 # Fixed: lowercase and proper spacing

selector: # Proper selector definition

matchLabels:

app: zamoto

metadata:

labels:

app: zamoto # Must match selector

spec:

containers:

- name: container1

image: shaikmustafa/mygame

ports:

- containerPort: 80

[root@ip-10-0-0-22 ~]# cat service.yaml

---

apiVersion: v1

kind: Service

metadata:

spec:

type: LoadBalancer

selector:

app: zamoto

ports:

- port: 80

targetPort: 80

Step4: So far deployment

pod-->container

rc/rs -->pod-->contrainer

deploy -->rs-->pod -->container

Deployment feature: autoscaling,need to provide these information while deployment,if pod usage 60 % percentage usage pod will create, if usage is less pod will reduced

replication
Scaling(manuall,autoscaling) Autoscalimg:
desired:3
min:2
max10
Rollback to any version
no downtime

Step5: All instance created successfully.

[root@ip-10-0-0-22 ~]# kops validate cluster --wait 10m

[ec2-user@ip-10-0-0-22 ~]$ kubectl get nodes

NAME STATUS ROLES AGE VERSION

i-012484f05449c29f6 Ready control-plane 3m36s v1.32.4

i-0c9c5c020ce9ab366 Ready node 73s v1.32.4

i-0e71b4d0cc69c02c6 Ready node 85s v1.32.4

Step6: Using below command execute manifest file,

[root@ip-10-0-0-22 ~]# kubectl create -f .

deployment.apps/mydeploy created

service/myservice created

Step7: Deployment create , along with replicaset will come

[root@ip-10-0-0-22 ~]# kubectl get deploy

NAME READY UP-TO-DATE AVAILABLE AGE

mydeploy 2/2 2 2 47s

[root@ip-10-0-0-22 ~]# kubectl get rs

NAME DESIRED CURRENT READY AGE

mydeploy-77d4499fd4 2 2 2 104s

Step8: list of Pods

[root@ip-10-0-0-22 ~]# kubectl get pods

NAME READY STATUS RESTARTS AGE

mydeploy-77d4499fd4-7j2xs 1/1 Running 0 2m6s

mydeploy-77d4499fd4-kldnq 1/1 Running 0 2m6s

Step9:list of Services

[root@ip-10-0-0-22 ~]# kubectl get svc

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE

kubernetes ClusterIP 100.64.0.1 <none> 443/TCP 6m29s

myservice LoadBalancer 100.71.88.229 a8ba63cae87274680944e81acc4a3da6-2050377277.eu-west-2.elb.amazonaws.com 80:30315/TCP 2m56s

Step10: loadbalancer opened

Step11:

[root@ip-10-0-0-22 ~]# kubectl get deploy

NAME READY UP-TO-DATE AVAILABLE AGE

mydeploy 2/2 2 2 11m

[root@ip-10-0-0-22 ~]# kubectl describe deploy

Name: mydeploy

Namespace: default

CreationTimestamp: Sun, 17 Aug 2025 13:31:01 +0000

Labels: <none>

Annotations: deployment.kubernetes.io/revision: 1

Selector: app=zamoto

Replicas: 2 desired | 2 updated | 2 total | 2 available | 0 unavailable

StrategyType: RollingUpdate

MinReadySeconds: 0

RollingUpdateStrategy: 25% max unavailable, 25% max surge

Pod Template:

Labels: app=zamoto

Containers:

container1:

Image: shaikmustafa/mygame

Port: 80/TCP

Host Port: 0/TCP

Environment: <none>

Mounts: <none>

Volumes: <none>

Node-Selectors: <none>

Tolerations: <none>

Conditions:

Type Status Reason

---- ------ ------

Available True MinimumReplicasAvailable

Progressing True NewReplicaSetAvailable

OldReplicaSets: <none>

NewReplicaSet: mydeploy-77d4499fd4 (2/2 replicas created)

Events:

Type Reason Age From Message

---- ------ ---- ---- -------

Normal ScalingReplicaSet 11m deployment-controller Scaled up replica set mydeploy-77d4499fd4 from 0 to 2

Test our features

No down time

Step12: Change the deployment file image changed

[root@ip-10-0-0-22 ~]# vi manifest.yaml

image: shaikmustafa/dm

[root@ip-10-0-0-22 ~]# kubectl apply -f manifest.yaml

Warning: resource deployments/mydeploy is missing the kubectl.kubernetes.io/last-applied-configuration annotation which is required by kubectl apply. kubectl apply should only be used on resources created declaratively by either kubectl create --save-config or kubectl apply. The missing annotation will be patched automatically.

deployment.apps/mydeploy configured

See without downtime ,deployed changed to another webpage

Step13: Though command also we can change image

[root@ip-10-0-0-22 ~]# kubectl set image deploy mydeploy container1=shaikmustafa/cycle

deployment.apps/mydeploy image updated

Step14: Below command rollout can able check ,image deployed or not

[root@ip-10-0-0-22 ~]# kubectl rollout status deploy mydeploy

deployment "mydeploy" successfully rolled out

Step15: shaikmustafa/paytm:movie

[root@ip-10-0-0-22 ~]# kubectl set image deploy mydeploy container1=shaikmustafa/paytm:movie

deployment.apps/mydeploy image updated

[root@ip-10-0-0-22 ~]# kubectl rollout status deploy mydeploy

Waiting for deployment "mydeploy" rollout to finish: 1 out of 2 new replicas have been updated...

Waiting for deployment "mydeploy" rollout to finish: 1 old replicas are pending termination...

deployment "mydeploy" successfully rolled out

[root@ip-10-0-0-22 ~]#

Step16:

Deployment -->RS 1--> 3 pods created First game

After Image updated --RS2 --> 1 pod will create after successfully deployed, remove one pod in Rs1, Same way 2 pod will create after successfully deployed , remove second pod in Rs1

Same way 3 prod will create after successfully deployed ,demote third pod,

all pods deployed into new version application.

This called this strategy in technically "rolling update strategy"

Step17: Planning to rollback the application

After change Replicateset , previous set are not delete it should be presist , you can able to rollback

previous application ,now below one is active one , now the application is paytm movie,

Planning to change Rs3 desire rollback

[root@ip-10-0-0-22 ~]# kubectl get rs

NAME DESIRED CURRENT READY AGE

mydeploy-547d4c47c7 0 0 0 50m

mydeploy-5f87bb8854 0 0 0 36m

mydeploy-77d4499fd4 0 0 0 65m

mydeploy-8565b4b985 2 2 2 30m

Undo command

Here 3 is version

[root@ip-10-0-0-22 ~]# kubectl rollout undo deployment mydeploy --to-revision=3

deployment.apps/mydeploy rolled back

[root@ip-10-0-0-22 ~]# kubectl rollout status deploy mydeploy

deployment "mydeploy" successfully rolled out

Application change to cycle

See here rs active state changed from mydeploy-8565b4b985 to mydeploy-5f87bb8854

[root@ip-10-0-0-22 ~]# kubectl get rs

NAME DESIRED CURRENT READY AGE

mydeploy-547d4c47c7 0 0 0 58m

mydeploy-5f87bb8854 2 2 2 44m

mydeploy-77d4499fd4 0 0 0 73m

mydeploy-8565b4b985 0 0 0 38m

This command will show like 1 pod i creating another pod is terminiated

-w mean watch

[root@ip-10-0-0-22 ~]# kubectl get po -w

NAME READY STATUS RESTARTS AGE

mydeploy-5f87bb8854-b9rp7 0/1 ContainerCreating 0 0s

mydeploy-5f87bb8854-mrbws 1/1 Running 0 3s

mydeploy-8565b4b985-7pv2w 1/1 Terminating 0 57s

mydeploy-8565b4b985-d4lrj 1/1 Running 0 55s

mydeploy-8565b4b985-7pv2w 0/1 Completed 0 58s

mydeploy-8565b4b985-7pv2w 0/1 Completed 0 59s

mydeploy-5f87bb8854-b9rp7 1/1 Running 0 3s

mydeploy-8565b4b985-d4lrj 1/1 Terminating 0 58s

See here i have change version 4

[root@ip-10-0-0-22 ~]# kubectl rollout undo deployment mydeploy --to-revision=4

deployment.apps/mydeploy rolled back

[root@ip-10-0-0-22 ~]# kubectl get po -w

NAME READY STATUS RESTARTS AGE

mydeploy-8565b4b985-7pv2w 1/1 Running 0 11s

mydeploy-8565b4b985-d4lrj 1/1 Running 0 9s

Planning to back to version 2 ,it should not available version 3 will change version 5

[root@ip-10-0-0-22 ~]# kubectl rollout undo deployment mydeploy --to-revision=3

error: unable to find specified revision 3 in history

[root@ip-10-0-0-22 ~]# kubectl rollout undo deployment mydeploy --to-revision=5

deployment.apps/mydeploy rolled back

Now the current application is Cycle

Step18: see here history of deployment version 3 was removed

[root@ip-10-0-0-22 ~]# kubectl rollout history deploy mydeploy

deployment.apps/mydeploy

REVISION CHANGE-CAUSE

1 <none>

2 <none>

6 <none>

7 <none>

[root@ip-10-0-0-22 ~]# kubectl rollout undo deployment mydeploy --to-revision=2

deployment.apps/mydeploy rolled back

[root@ip-10-0-0-22 ~]# kubectl get po -w

NAME READY STATUS RESTARTS AGE

mydeploy-547d4c47c7-4cmnc 1/1 Running 0 4s

mydeploy-547d4c47c7-tfp6p 0/1 ContainerCreating 0 1s

mydeploy-5f87bb8854-b9rp7 1/1 Running 0 9m29s

mydeploy-547d4c47c7-tfp6p 1/1 Running 0 2s

mydeploy-5f87bb8854-b9rp7 1/1 Terminating 0 9m31s

mydeploy-5f87bb8854-b9rp7 0/1 Completed 0 9m32s

mydeploy-5f87bb8854-b9rp7 0/1 Completed 0 9m33s

[root@ip-10-0-0-22 ~]# kubectl rollout history deploy mydeploy

deployment.apps/mydeploy

REVISION CHANGE-CAUSE

1 <none>

6 <none>

7 <none>

8 <none>

Step19: delete the pod , need to check automatically created or not

See after deleted all pod ,created pod 5 sec automatically

[root@ip-10-0-0-22 ~]# kubectl get pods

NAME READY STATUS RESTARTS AGE

mydeploy-547d4c47c7-4cmnc 1/1 Running 0 3m25s

mydeploy-547d4c47c7-tfp6p 1/1 Running 0 3m22s

[root@ip-10-0-0-22 ~]# kubectl delete pod --all

pod "mydeploy-547d4c47c7-4cmnc" deleted

pod "mydeploy-547d4c47c7-tfp6p" deleted

[root@ip-10-0-0-22 ~]# kubectl get pods

NAME READY STATUS RESTARTS AGE

mydeploy-547d4c47c7-b22bc 1/1 Running 0 5s

mydeploy-547d4c47c7-t9x4z 1/1 Running 0 5s

Step20: manually scalein , first increase the pods

[root@ip-10-0-0-22 ~]# cat manifest.yaml

---

apiVersion: apps/v1

kind: Deployment

metadata:

name: mydeploy

spec:

replicas: 4 # Fixed: lowercase and proper spacing

selector: # Proper selector definition

matchLabels:

app: zamoto

template: # Moved to top-level under spec

metadata:

labels:

app: zamoto # Must match selector

spec:

containers:

- name: container1

image: shaikmustafa/dm

ports:

- containerPort: 80

[root@ip-10-0-0-22 ~]# kubectl apply -f manifest.yaml

deployment.apps/mydeploy configured

[root@ip-10-0-0-22 ~]# kubectl get po

NAME READY STATUS RESTARTS AGE

mydeploy-547d4c47c7-b22bc 1/1 Running 0 4m45s

mydeploy-547d4c47c7-sgkc7 1/1 Running 0 9s

mydeploy-547d4c47c7-t9x4z 1/1 Running 0 4m45s

mydeploy-547d4c47c7-zstz8 1/1 Running 0 9s

Scaledown using command:

[root@ip-10-0-0-22 ~]# kubectl scale deploy mydeploy --replicas 2

deployment.apps/mydeploy scaled

[root@ip-10-0-0-22 ~]# kubectl get po

NAME READY STATUS RESTARTS AGE

mydeploy-547d4c47c7-b22bc 1/1 Running 0 5m55s

mydeploy-547d4c47c7-t9x4z 1/1 Running 0 5m55s

Step21: Auto scaling ,Prod metric

metric for the server

https://kubernetes-sigs.github.io/metrics-server/

kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/high-availability.yaml

[root@ip-10-0-0-22 ~]# curl -LO https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/high-availability.yaml

% Total % Received % Xferd Average Speed Time Time Time Current

Dload Upload Total Spent Left Speed

0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0

100 4871 100 4871 0 0 16938 0 --:--:-- --:--:-- --:--:-- 16938

[root@ip-10-0-0-22 ~]# sed -i 's|policy/v1beta1|policy/v1|g' high-availability.yaml

[root@ip-10-0-0-22 ~]# kubectl apply -f high-availability.yaml

serviceaccount/metrics-server unchanged

clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader unchanged

clusterrole.rbac.authorization.k8s.io/system:metrics-server unchanged

rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader unchanged

clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator unchanged

clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server unchanged

service/metrics-server unchanged

deployment.apps/metrics-server configured

poddisruptionbudget.policy/metrics-server created

apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io unchanged

Below command metric-server installed or not using below command

[root@ip-10-0-0-22 ~]# kubectl get deployment metrics-server -n kube-system

NAME READY UP-TO-DATE AVAILABLE AGE

metrics-server 2/2 2 2 5m39s

[root@ip-10-0-0-22 ~]# cat hp.yaml

apiVersion: autoscaling/v2

kind: HorizontalPodAutoscaler

metadata:

spec:

scaleTargetRef:

apiVersion: apps/v1

kind: Deployment

minReplicas: 1

maxReplicas: 5

metrics:

- type: Resource

resource:

target:

type: Utilization

averageUtilization: 50 # Target 50% CPU utilization

Deployment created ,autoscaling will work once 50 % cpu ultization, so you need give command stress to server.

[root@ip-10-0-0-22 ~]# kubectl create -f hp.yaml

horizontalpodautoscaler.autoscaling/nginx-hpa created

Step22: Go to inside the pod

[root@ip-10-0-0-22 ~]# kubectl get po

NAME READY STATUS RESTARTS AGE

mydeploy-547d4c47c7-b22bc 1/1 Running 0 25m

mydeploy-547d4c47c7-t9x4z 1/1 Running 0 25m

[root@ip-10-0-0-22 ~]# kubectl exec -it mydeploy-547d4c47c7-t9x4z -- bash

root@mydeploy-547d4c47c7-t9x4z:/#

Step23:

root@mydeploy-547d4c47c7-t9x4z:/# apt update -y

root@mydeploy-547d4c47c7-t9x4z:/# apt install stress -y

root@mydeploy-547d4c47c7-t9x4z:/# stress -c 2 400 -v

stress: FAIL: [305] (244) unrecognized option: 400

root@mydeploy-547d4c47c7-t9x4z:/# stress -c 2 -t 400 -v

stress: info: [306] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd

stress: dbug: [306] using backoff sleep of 6000us

stress: dbug: [306] setting timeout to 400s

stress: dbug: [306] --> hogcpu worker 2 [307] forked

stress: dbug: [306] using backoff sleep of 3000us

stress: dbug: [306] setting timeout to 400s

stress: dbug: [306] --> hogcpu worker 1 [308] forked

Step24: See below previous 2 pods only, after stress server 5 pods automatically created

See here 5 pods created

Step25: Once you cancel the stress automatically pod will reduced, it will take time

Delete the cluster:

[root@ip-10-0-0-22 ~]# export KOPS_STATE_STORE=s3://ccitpublicbucket16

[root@ip-10-0-0-22 ~]# kops delete cluster --name kopsclstr.k8s.local --yes

Deleted kubectl config for kopsclstr.k8s.local

Deleted cluster: "kopsclstr.k8s.local"

--Thanks

Knowledge

Friday, August 15, 2025

Kubernetes part5

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