Kubernetes Part4

Kubernetes Part4

Class 88th Kubernetes Part4 August 14th 

Replication and Deployment

Step1:Create one Ec2  machine, For Install kubectl, install the cluster Kops

go though part3 

https://kops.sigs.k8s.io/getting_started/install/

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

Client version: 1.33.0 (git-v1.33.0)

Step2: Replication controller, This one of the cluster when every delete the pod ,automatically create one more pod this Kubernetes give feature.

Step3: Create 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

--List of cluster

[root@ip-10-0-0-22 ~]# kops get cluster

NAME                    CLOUD   ZONES

kopsclstr.k8s.local     aws     eu-west-2a,eu-west-2b

The Draw Back

In the above both methos we can be able create a pod but what if we delete the pod?

One you delete thw pod we cannot able to access the pod, so it will create a lot difficulty in real time.

Note: Self healing is not available here.

To Overcome this on we use some kubernetes components called RC,RS, 

Deployment ,Deamon SETS ,etc..

(Pod object, RC replication control, RS Replication sets)

REPLICAS IN KUBERNETES:

·       Before Kubernetes, other tools did not provide important and customized feature like scaling and replication.

·       When Kubernetes was introduced, replication and scaling were the premium features that increased the popularity of this container orchestration tool.

·       Replication means that if the pods desired state is set to  3 and whatever any pod fails, this will lead to a reduction in the downtime of the application.

·       Scaling means if the load becomes increases on the application, then Kubernetes increase the number of pods according to the load on the application

• ReplicationController is an object in kubernetes that was introduced in v1 of kubernetes which helps to meet the desired state of the kubernetes cluster from the current state.Replicationcontroller works on requality-base controllers only.
• ReplicaSet is an object in Kubernetes and it is an advanced version of ReplicationController. ReplicaSet works on the Equality-base controllers and set-base Controllers.

Step3: First We create the RC, RC will create the Pods ,we need inform the RC how many pods are required ,RC maintained the Pods every 5 sec it will check ,if any pod went down replication controller 

automatically create the Pod , We can create replicationController Two ways 

1.Imperative 2.Declarative (manifest file) we use this real time

[root@ip-10-0-0-22 ~]# export KOPS_STATE_STORE=s3://ccitpublicbucket1

Part1: Replicationcontroller with name myrc

Part2: pod creation, Replicationcontroller specification, count 3 , selector is select the label using template created metadata  added the labels, for every pod one label will create

Part3: Container 

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

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

apiVersion: v1

kind: ReplicationController

metadata:

  name: myrc

spec:

  replicas: 3  # Fixed: lowercase and proper spacing

  selector:    # Proper selector definition

    app: swiggy

  template:    # Moved to top-level under spec

    metadata:

      labels:

        app: swiggy  # Must match selector

    spec:

      containers:

      - name: container1

        image: shaikmustafa/cycle

        ports:

        - containerPort: 80

Step4: As you observer myrc name of replicate some random name attached 

Before

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

No resources found in default namespace.

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

replicationcontroller/myrc created

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

After :

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

NAME         READY   STATUS    RESTARTS   AGE

myrc-bvch9   1/1     Running   0          2m54s

myrc-g6w5t   1/1     Running   0          2m54s

myrc-h58kj   1/1     Running   0          2m54s

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

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

NAME   DESIRED   CURRENT   READY   AGE

myrc   3         3         3       3m41s

Step5: See Deleted one pod myrc-bvch9, automatically 9sec ,created one more pod 

[root@ip-10-0-0-22 ~]# kubectl delete pod myrc-bvch9

pod "myrc-bvch9" deleted

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

NAME         READY   STATUS    RESTARTS   AGE     LABELS

myrc-g6w5t   1/1     Running   0          7m53s   app=swiggy

myrc-h58kj   1/1     Running   0          7m53s   app=swiggy

myrc-mmbts   1/1     Running   0          9s    app=swiggy

Step6 : Delete all pods ,see 4s create all pods automatically

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

pod "myrc-g6w5t" deleted

pod "myrc-h58kj" deleted

pod "myrc-mmbts" deleted

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

NAME         READY   STATUS    RESTARTS   AGE   LABELS

myrc-ccctm   1/1     Running   0          4s    app=swiggy

myrc-x4slc   1/1     Running   0          4s    app=swiggy

myrc-zxwnd   1/1     Running   0          4s    app=swiggy

Expose the Pods , Need to create Service file 

Step7: Service created 

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

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

---

apiVersion: v1

kind: Service

metadata:

  name: myservice

spec:

  type: LoadBalancer

  selector:

    app: swiggy

  ports:

    - port: 80

      targetPort: 80

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

service/myservice created

Step8: See below stable ip and loadbalancer dns came automatically 

--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        29m

myservice    LoadBalancer   100.66.58.204   ae126a2383e494e72af8aa2c68283098-161964620.eu-west-2.elb.amazonaws.com   80:31062/TCP   52s

Step9: let try delete all pod and try to access the application, even after create able to access the application 

Step10: if you want to create more pods, you need modify the replicate count change,

technical we can called pods increasing scalein, decreaing scaleout 

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

  replicas: 5  # Fixed: lowercase and proper spacing

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

Warning: resource replicationcontrollers/myrc 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.

replicationcontroller/myrc configured

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

NAME         READY   STATUS    RESTARTS   AGE     LABELS

myrc-6kht8   1/1     Running   0          7m23s   app=swiggy

myrc-7pvh6   1/1     Running   0          21s     app=swiggy

myrc-88kv4   1/1     Running   0          21s     app=swiggy

myrc-jhg8d   1/1     Running   0          7m23s   app=swiggy

myrc-ljcpb   1/1     Running   0          7m23s   app=swiggy

Step11: Decrease  Scaledown

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

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

replicationcontroller/myrc configured

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

NAME         READY   STATUS    RESTARTS   AGE   LABELS

myrc-6kht8   1/1     Running   0          10m   app=swiggy

myrc-jhg8d   1/1     Running   0          10m   app=swiggy

myrc-ljcpb   1/1     Running   0          10m   app=swiggy

Step12: Using command also we can increase the pods 

[root@ip-10-0-0-22 ~]# kubectl scale rc myrc --replicas 4

replicationcontroller/myrc scaled

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

NAME         READY   STATUS    RESTARTS   AGE   LABELS

myrc-6kht8   1/1     Running   0          13m   app=swiggy

myrc-hl89f   1/1     Running   0          5s    app=swiggy

myrc-jhg8d   1/1     Running   0          13m   app=swiggy

myrc-ljcpb   1/1     Running   0          13m   app=swiggy

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

Step13: Decrease 

[root@ip-10-0-0-22 ~]# kubectl scale rc myrc --replicas 1

replicationcontroller/myrc scaled

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

NAME         READY   STATUS    RESTARTS   AGE   LABELS

myrc-6kht8   1/1     Running   0          14m   app=swiggy

Step14: full information of rc ,events 

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

Name:         myrc

Namespace:    default

Selector:     app=swiggy

Labels:       app=swiggy

Annotations:  <none>

Replicas:     1 current / 1 desired

Pods Status:  1 Running / 0 Waiting / 0 Succeeded / 0 Failed

Pod Template:

  Labels:  app=swiggy

  Containers:

   container1:

    Image:         shaikmustafa/cycle

    Port:          80/TCP

    Host Port:     0/TCP

    Environment:   <none>

    Mounts:        <none>

  Volumes:         <none>

  Node-Selectors:  <none>

  Tolerations:     <none>

Events:

  Type    Reason            Age                 From                    Message

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

  Normal  SuccessfulCreate  32m                 replication-controller  Created pod: myrc-g6w5t

  Normal  SuccessfulCreate  32m                 replication-controller  Created pod: myrc-bvch9

  Normal  SuccessfulCreate  32m                 replication-controller  Created pod: myrc-h58kj

  Normal  SuccessfulCreate  26m                 replication-controller  Created pod: myrc-mmbts

  Normal  SuccessfulCreate  23m                 replication-controller  Created pod: myrc-ccctm

  Normal  SuccessfulCreate  23m                 replication-controller  Created pod: myrc-x4slc

  Normal  SuccessfulCreate  23m                 replication-controller  Created pod: myrc-zxwnd

  Normal  SuccessfulCreate  15m                 replication-controller  Created pod: myrc-ljcpb

  Normal  SuccessfulCreate  15m                 replication-controller  Created pod: myrc-6kht8

  Normal  SuccessfulDelete  4m39s               replication-controller  Deleted pod: myrc-88kv4

  Normal  SuccessfulDelete  4m39s               replication-controller  Deleted pod: myrc-7pvh6

  Normal  SuccessfulCreate  2m9s (x4 over 15m)  replication-controller  (combined from similar events): Created pod: myrc-hl89f

  Normal  SuccessfulDelete  75s                 replication-controller  Deleted pod: myrc-hl89f

  Normal  SuccessfulDelete  75s                 replication-controller  Deleted pod: myrc-jhg8d

  Normal  SuccessfulDelete  75s                 replication-controller  Deleted pod: myrc-ljcpb

Advantage :replicate and scaling 

Drawback if this: it is equality based selector, not setbase selector 

 For ex:-  Equality based selector app: swiggy 

                 Set based selector app in swiggy ,zamoto

RC : at time we can access single label, to over come this issue need to use RS(ReplicateSet)

                                                               replicaSet

New version of Kuberenets 

Step1: Delete the existing my rc 

[root@ip-10-0-0-22 ~]# kubectl delete rc myrc

replicationcontroller "myrc" deleted

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

No resources found in default namespace.

--To Check  rs version apps/v1

[root@ip-10-0-0-22 ~]# kubectl api-resources | grep -i "rs"

NAME                                SHORTNAMES                          APIVERSION                        NAMESPACED   KIND

persistentvolumeclaims              pvc                                 v1                                true         PersistentVolumeClaim

persistentvolumes                   pv                                  v1                                false        PersistentVolume

replicationcontrollers              rc                                  v1                                true         ReplicationController

replicasets                         rs                                  apps/v1                           true         ReplicaSet

horizontalpodautoscalers            hpa                                 autoscaling/v2                    true         HorizontalPodAutoscaler

csidrivers                                                              storage.k8s.io/v1                 false        CSIDriver

Step2:

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

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

---

apiVersion: apps/v1

kind: ReplicaSet

metadata:

  name: myrs

spec:

  replicas: 2  # Fixed: lowercase and proper spacing

  selector:    # Proper selector definition

    matchLabels:

      app: swiggy

  template:    # Moved to top-level under spec

    metadata:

      labels:

        app: swiggy  # Must match selector

    spec:

      containers:

      - name: container1

        image: shaikmustafa/cycle

        ports:

        - containerPort: 80

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

replicaset.apps/myrs created

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

NAME   DESIRED   CURRENT   READY   AGE

myrs   2         2         2       97s

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

NAME         READY   STATUS    RESTARTS   AGE     LABELS

myrs-dzz9s   1/1     Running   0          2m53s   app=swiggy

myrs-hqdpj   1/1     Running   0          2m53s   app=swiggy

Command  scaling 

Step3: Scalein

[root@ip-10-0-0-22 ~]# kubectl scale rs myrs  --replicas 4

replicaset.apps/myrs scaled

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

NAME         READY   STATUS    RESTARTS   AGE     LABELS

myrs-dzz9s   1/1     Running   0          4m33s   app=swiggy

myrs-fjddd   1/1     Running   0          4s      app=swiggy

myrs-hqdpj   1/1     Running   0          4m33s   app=swiggy

myrs-zw2mp   1/1     Running   0          4s      app=swiggy

Step4:Scaleout

[root@ip-10-0-0-22 ~]# kubectl scale rs myrs  --replicas 1

replicaset.apps/myrs scaled

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

NAME         READY   STATUS    RESTARTS   AGE     LABELS

myrs-dzz9s   1/1     Running   0          4m51s   app=swiggy

Full information of the RS

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

Name:         myrs

Namespace:    default

Selector:     app=swiggy

Labels:       <none>

Annotations:  <none>

Replicas:     1 current / 1 desired

Pods Status:  1 Running / 0 Waiting / 0 Succeeded / 0 Failed

Pod Template:

  Labels:  app=swiggy

  Containers:

   container1:

    Image:         shaikmustafa/cycle

    Port:          80/TCP

    Host Port:     0/TCP

    Environment:   <none>

    Mounts:        <none>

  Volumes:         <none>

  Node-Selectors:  <none>

  Tolerations:     <none>

Events:

  Type    Reason            Age    From                   Message

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

  Normal  SuccessfulCreate  7m     replicaset-controller  Created pod: myrs-hqdpj

  Normal  SuccessfulCreate  7m     replicaset-controller  Created pod: myrs-dzz9s

  Normal  SuccessfulCreate  2m31s  replicaset-controller  Created pod: myrs-zw2mp

  Normal  SuccessfulCreate  2m31s  replicaset-controller  Created pod: myrs-fjddd

  Normal  SuccessfulDelete  2m12s  replicaset-controller  Deleted pod: myrs-fjddd

  Normal  SuccessfulDelete  2m12s  replicaset-controller  Deleted pod: myrs-hqdpj

  Normal  SuccessfulDelete  2m12s  replicaset-controller  Deleted pod: myrs-zw2mp

Drawback 

manual scaling here no autscaling ,rollback, exist dowtime it will take some time delay to create pods

Deployment :

 Replica, manual scaling ,SBS, nodowntime

Step1:

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

---

apiVersion: apps/v1

kind: Deployment

metadata:

  name: mydeploy

spec:

  replicas: 2  # Fixed: lowercase and proper spacing

  selector:    # Proper selector definition

    matchLabels:

      app: swiggy

  template:    # Moved to top-level under spec

    metadata:

      labels:

        app: swiggy  # Must match selector

    spec:

      containers:

      - name: container1

        image: shaikmustafa/cycle

        ports:

Step2:

Deployment create successfully

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

deployment.apps/mydeploy created

 below both are same 

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

NAME                  DESIRED   CURRENT   READY   AGE

mydeploy-5fc87dd57b   2         2         2       17s

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

NAME       READY   UP-TO-DATE   AVAILABLE   AGE

mydeploy   2/2     2            2           40s

Step3:

[root@ip-10-0-0-22 ~]# kops get cluster

NAME                    CLOUD   ZONES

kopsclstr.k8s.local     aws     eu-west-2a,eu-west-2b

[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"

Based on  if you learn one ReplicateController remaing all are similar, RS,Deployment 

                                             Deamonset ,stateful

Sofar 5 manifest file learned(pods,service,rc,rs,deployment) total 9

Reference Document: 

https://mustafa-k8s.hashnode.dev/replication-controller-vs-replica-set

--Thanks 

Kubernetes part3

Kubernetes part3

Class 87th Kubernetes Part3 August 13th 

Multi node cluster 

Cluster (group of master and worker server called cluster)

Operator server/User server (kubectl) --> send request to create pod-->API Server --> Scheduler decided 

which worker node create and inform back to API server --> API server will create Pod in worker node.

Practical : 

Step1: Create Ec2 instance Kops Instanace name take instance t3.micro okay, 20 GB disk for master c7.flex.large required,worker nodes 2 t3.micro

Install Kubectl  https://kubernetes.io/docs/tasks/tools/

[root@ip-10-0-0-22 bin]# curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

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

                                 Dload  Upload   Total   Spent    Left  Speed

100   138  100   138    0     0   1103      0 --:--:-- --:--:-- --:--:--  1112

100 57.3M  100 57.3M    0     0   101M      0 --:--:-- --:--:-- --:--:--  101M

[root@ip-10-0-0-22 bin]# mv kubectl /usr/local/bin

[root@ip-10-0-0-22 bin]# kubectl version

[root@ip-10-0-2-52 bin]# chmod 777 kubectl

[root@ip-10-0-2-52 bin]# kubectl version

Client Version: v1.33.4

Kustomize Version: v5.6.0

Step2: kops installation steps  Linux directly past to the server 

 

https://kops.sigs.k8s.io/getting_started/install/

[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

[root@ip-10-0-0-22 ~]# chmod +x kops

[root@ip-10-0-0-22 ~]#sudo mv kops /usr/local/bin/kops

  % 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  274M  100  274M    0     0  48.3M      0  0:00:05  0:00:05 --:--:-- 52.1M

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

Client version: 1.33.0 (git-v1.33.0)

Step3: Cluster information ,storing in AWS S3 bucket 

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

Unable to locate credentials. You can configure credentials by running "aws configure".

Attach the admin role to the Ec2 machine

Step4: Create one bucket version should be enabled "ccitpublicbucket16"

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

2025-08-16 16:58:08 ccitpublicbucket16

We need to inform kops cluster store the specific bucket store the cluster details 

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

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

Step5: Cluster creation 

https://kops.sigs.k8s.io/getting_started/aws/

Syntax:-

kops create cluster \ --name=${NAME} \ --cloud=aws \ --zones=us-west-2a \ --discovery-store=s3://prefix-example-com-oidc-store/${NAME}/discovery

Cluster name should be  <anyname>.k8s.local 

Below command ran once it will take (master and woker node will create at the end give some suggestion keep for same)

[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

Suggestions:

 * list clusters with: kops get cluster

 * edit this cluster with: kops edit cluster kopsclstr.k8s.local

 * edit your node instance group: kops edit ig --name=kopsclstr.k8s.local nodes-eu-west-2b

 * edit your control-plane instance group: kops edit ig --name=kopsclstr.k8s.local control-plane-eu-west-2b

Finally configure your cluster with: kops update cluster --name kopsclstr.k8s.local --yes --admin

Step6: as given suggestion run the command , it will take time to create 

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

kOps has set your kubectl context to kopsclstr.k8s.local

Cluster is starting.  It should be ready in a few minutes.

Suggestions:

 * validate cluster: kops validate cluster --wait 10m

 * list nodes: kubectl get nodes --show-labels

 * ssh to a control-plane node: ssh -i ~/.ssh/id_rsa ubuntu@

 * the ubuntu user is specific to Ubuntu. If not using Ubuntu please use the appropriate user based on your OS.

 * read about installing addons at: https://kops.sigs.k8s.io/addons.

Successfully created control plane node and two worker nodes 

Target Groups

Load balancer 

Autoscaling 

VPC 

In real time we are set infra using terraform script to eks -- it will take 45 minute 

But Kops it will completed in -5 minutes

Project we will do using terraform 

Step7: it will take some time minimum 10 mints to 15 minutes

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

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

NAME                  STATUS   ROLES           AGE     VERSION

i-03d052cacf647b877   Ready    node            59s     v1.32.4

i-0e8a3f4c3da2f1696   Ready    node            61s     v1.32.4

i-0f5f236564f4f7804   Ready    control-plane   3m11s   v1.32.4

Step8: We have successfully deploy the pods

I Can’t able to access my application

The reason why we are not able access the application : In Kubernetes, if you want to access the application we have to expose our pod. To expose these pods we use Kubernetes services.

Through Services in Kubernetes ,We export the pods different types

 Services: Cluster-Ip,node port,load balancer , external dns(not using)

Every pod have default one ip,with that ip we cannot able access application,we expose that ip

1. Cluster-IP :  using this cluster-ip service we can export pod, it use only for internal scop internal,external we can able access the application  internet

For ex:- it will provide stable ip or static ip using internal only ,use for database expose pod

using curl, we can test

2.Node Port : it will give you Stable ip  and also give the range node port range(30k-32656)

with this port range number , using worker node public ip access the application  in the pod 

Step8: Se below master node or control-plane and node or worker node are ready 

Server information :kubectl get no  -o also work

[root@ip-10-0-0-22 ~]# kubectl get node  -o wide

NAME                  STATUS   ROLES           AGE   VERSION   INTERNAL-IP      EXTERNAL-IP     OS-IMAGE             KERNEL-VERSION   CONTAINER-RUNTIME

i-03d052cacf647b877   Ready    node            10m   v1.32.4   172.20.151.201   3.8.130.16      Ubuntu 24.04.2 LTS   6.8.0-1029-aws   containerd://1.7.28

i-0e8a3f4c3da2f1696   Ready    node            10m   v1.32.4   172.20.72.207    3.10.152.129    Ubuntu 24.04.2 LTS   6.8.0-1029-aws   containerd://1.7.28

i-0f5f236564f4f7804   Ready    control-plane   12m   v1.32.4   172.20.180.173   35.176.113.95   Ubuntu 24.04.2 LTS   6.8.0-1029-aws   containerd://1.7.28

Step9: For pod creation manifest file need prepare 

Docker installation

[root@ip-10-0-0-22 ~]# yum install docker -y && systemctl start docker

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

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

apiVersion: v1

kind: Pod

metadata:

  name: pod-1

  labels:

    app: zamota

spec:

  containers:

    - name: container1

      image: shaikmustafa/dm

      ports:

        - containerPort: 80

Step10: it is asking user name and password , i have create own docker image

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

pod/pod-1 created

Created pod above successfully.

Step11: One pod created successfully 

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

NAME    READY   STATUS    RESTARTS   AGE   IP             NODE                  NOMINATED NODE   READINESS GATES

pod-1   1/1     Running   0          63s   100.96.3.131   i-03d052cacf647b877   <none>           <none>

Step12: How to check, pod details ,as you see scheduler tell ,create particular instance to  create the pod

[root@ip-10-0-0-22 ~]#  kubectl describe pod pod-1

Events:

  Type    Reason     Age    From               Message

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

  Normal  Scheduled  3m15s  default-scheduler  Successfully assigned default/pod-1 to i-03d052cacf647b877

  Normal  Pulling    3m14s  kubelet            Pulling image "shaikmustafa/dm"

  Normal  Pulled     3m9s   kubelet            Successfully pulled image "shaikmustafa/dm" in 4.892s (4.892s including waiting). Image size: 60099640 bytes.

  Normal  Created    3m9s   kubelet            Created container: container1

  Normal  Started    3m9s   kubelet            Started container container1

Step13: Service need to create  ,which service going to expose , go to that selector cluster 

clusterip ,we have given po port 80,we have give same to give port to service port also 80 

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

NAME    READY   STATUS    RESTARTS   AGE   LABELS

pod-1   1/1     Running   0          53m   app=zamoto

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

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

---

apiVersion: v1

kind: Service

metadata:

  name: myservice

spec:

  type: ClusterIP

  selector:

    app: zamato

  ports:

    - port: 80

      targetPort: 80

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

service/myservice created

Service create kubernetes default one , mysevice we have create our own

[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   23m

myservice    ClusterIP   100.68.51.206   <none>        80/TCP    10s

Cluster Stable ip 100.68.51.206 we can able access internal only using work/slave public ip

Step14: Worker node 

[root@ip-10-0-0-22 ~]# kubectl label pod pod-1 app=zamato --overwrite

pod/pod-1 labeled

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

NAME        ENDPOINTS         AGE

myservice   100.96.3.131:80   21m

Internal working worker/slave node stable link working fine

Step15: service  Command 

[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   58m

myservice    ClusterIP   100.68.51.206   <none>        80/TCP    35m

Full information of the service 

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

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

kubernetes   ClusterIP   100.64.0.1      <none>        443/TCP   59m   <none>

myservice    ClusterIP   100.68.51.206   <none>        80/TCP    36m   app=zamato

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

if you need yaml format 

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

apiVersion: v1

Json

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

Full information one service

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

Name:                     myservice

Namespace:                default

Labels:                   <none>

Annotations:              <none>

Selector:                 app=zamato

Type:                     ClusterIP

IP Family Policy:         SingleStack

IP Families:              IPv4

IP:                       100.68.51.206

IPs:                      100.68.51.206

Port:                     <unset>  80/TCP

TargetPort:               80/TCP

Endpoints:                100.96.3.131:80

Session Affinity:         None

Internal Traffic Policy:  Cluster

Events:                   <none>

Delete the service 

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

service "myservice" deleted

[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   63m

 Node Port 

It will provide you 

stable ip  --Internal use 

Node Port --Internal and external through internet (slave server using public ip along with node port -IP)

node port range : 30k -32656

Step1: Existing port just change the cluster IP  to node Ip  in servie.yaml file 

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

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

---

apiVersion: v1

kind: Service

metadata:

  name: myservice

spec:

  type: NodePort

  selector:

    app: zamato

  ports:

    - port: 80

      targetPort: 80

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

service/myservice created

[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        69m

myservice    NodePort    100.71.48.35   <none>        80:31048/TCP   21s

Step2: 

Stable ip try access internally 100.71.48.35

Step3: worker/slave node public ip 

curl 3.10.152.129:31048

Step4:

Try to open internet browser , if not able access open the port in security group  31048

Worker node 1

Worker node 2 with public ip

Step5: Real time we are not use ip address, Load balancer service 

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

service "myservice" deleted

Load balance :

Work it work load balancer in kubernetes

K8s svc -->Cloude provide -->LB (DNS) name wil provide -- >cctter.com 

It will give these use case 

Stable ip 

Node port 

DNS 

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

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

---

apiVersion: v1

kind: Service

metadata:

  name: myservice

spec:

  type: LoadBalancer

  selector:

    app: zamato

  ports:

    - port: 80

      targetPort: 80

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

service/myservice created

[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        86m

myservice    LoadBalancer   100.68.221.171   a7655f520a3d44cd98e3fdff6def1af1-351032056.eu-west-2.elb.amazonaws.com   80:32627/TCP   21s

Step6: checking with stable IP

ubuntu@i-03d052cacf647b877:~$ curl 100.68.221.171

<!doctype html>

<html lang="en">

Step7: Able to access application node port 

Step8: Need to with loadbalancer/dns name  , it will not work immediately ,it will take time to 

1 minute to comunicate

a7655f520a3d44cd98e3fdff6def1af1-351032056.eu-west-2.elb.amazonaws.com 

Now load will transfer to two workers not equally.

Step 9: Need to delete the Cluster after completion using command only not manually , if you are manually delete ,autoscaling trying create parallel ,so do command

Below delete the cluster give this command

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

Out cluster information will store in this s3 bucket ccitpublicbucket16

Step10:

 API endpoint and services:

[root@ip-10-0-0-22 ~]# kubectl cluster-info

Kubernetes control plane is running at https://api-kopsclstr-k8s-local-0kba4s-37d4891bf709009e.elb.eu-west-2.amazonaws.com

CoreDNS is running at https://api-kopsclstr-k8s-local-0kba4s-37d4891bf709009e.elb.eu-west-2.amazonaws.com/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

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

 cluster state and configuration:

[root@ip-10-0-0-22 ~]# kops get cluster

NAME                    CLOUD   ZONES

kopsclstr.k8s.local     aws     eu-west-2a,eu-west-2

node health:

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

NAME                  STATUS   ROLES           AGE    VERSION

i-03d052cacf647b877   Ready    node            103m   v1.32.4

i-0e8a3f4c3da2f1696   Ready    node            103m   v1.32.4

i-0f5f236564f4f7804   Ready    control-plane   105m   v1.32.4

system components:

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

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

subnet:subnet-014cdb83033135899 ok

security-group:sg-0c7c7e35635a07319     ok

route-table:rtb-0d6c56defcbad4db3       ok

vpc:vpc-08692f993cc46837f       ok

dhcp-options:dopt-03b1723c1a058a166     ok

Deleted kubectl config for kopsclstr.k8s.local

Deleted cluster: "kopsclstr.k8s.local"

--All will create , Autoscaling,instance,loadbalancer,

KOPS Server only you need manually delete.

Reference document:

https://mustafa-k8s.hashnode.dev/kops-kubernetes-operations-the-ultimate-guide-for-devops-engineers

--Thanks