DEV Community

Cover image for K8s Exercise : Core Concepts
Akshay Rao
Akshay Rao

Posted on • Edited on

K8s Exercise : Core Concepts

#kubernetes #devops #opensource

Introduction
Hi, I am Akshay Rao, will be starting a exercise series on k8s.
In this blog there will not explanation only problems and solutions.if you want explanation have a look at this series:-
https://dev.to/aksrao1998/series/24887

Pre-requisite
have minikube or kind running in the local machine.

Note:- k is alias for kubectl.

Let's Start

Problem 1
Create a namespace called 'mynamespace' and a pod with image nginx called nginx on this namespace.

Solution

[k8s-ckad (⎈|minikube:default)]$ k get ns NAME STATUS AGE default Active 9d hands-on Active 9d kube-node-lease Active 9d kube-public Active 9d kube-system Active 9d [k8s-ckad (⎈|minikube:default)]$ k create namespace mynamespace namespace/mynamespace created [k8s-ckad (⎈|minikube:default)]$ k config set-context --current --namespace=mynamespace Context "minikube" modified. # deploy a pod [k8s-ckad (⎈|minikube:mynamespace)]$ kubectl run nginx --image=nginx --dry-run=client -o yaml > pods.yaml # edit the pods.yaml metadata: creationTimestamp: null labels: run: nginx name: nginx namespace: mynamespace # verify [k8s-ckad (⎈|minikube:mynamespace)]$ k create -f pods.yaml pod/nginx created [k8s-ckad (⎈|minikube:mynamespace)]$ k get po NAME READY STATUS RESTARTS AGE nginx 1/1 Running 0 6s
Enter fullscreen mode Exit fullscreen mode

Problem 2
Create a busybox pod (using kubectl command) that runs the command "env". Run it and see the output.

Solution

[k8s-ckad (⎈|minikube:mynamespace)]$ k run soln2 --image=busybox --command --restart=Never -it --rm -- env PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin HOSTNAME=soln2 TERM=xterm KUBERNETES_PORT_443_TCP_PROTO=tcp KUBERNETES_PORT_443_TCP_PORT=443 KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1 KUBERNETES_SERVICE_HOST=10.96.0.1 KUBERNETES_SERVICE_PORT=443 KUBERNETES_SERVICE_PORT_HTTPS=443 KUBERNETES_PORT=tcp://10.96.0.1:443 KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443 HOME=/root pod "soln2" deleted
Enter fullscreen mode Exit fullscreen mode

Problem 3
Create the YAML for a new ResourceQuota called 'myrq' with hard limits of 1 CPU, 1G memory and 2 pods without creating it

Solution

[k8s-ckad (⎈|minikube:mynamespace)]$ k create quota myrq --hard=cpu=1,memory=1G,pods=2 --dry-run=client -o y aml apiVersion: v1 kind: ResourceQuota metadata: creationTimestamp: null name: myrq spec: hard: cpu: "1" memory: 1G pods: "2" status: {}
Enter fullscreen mode Exit fullscreen mode

Problem 4

Create a pod with image nginx:1.25.1 called nginx and expose traffic on port 80

Solution

[k8s-ckad (⎈|minikube:mynamespace)]$ k run mypod --image=nginx:1.25.1 --port=80 pod/mypod created #Verify [k8s-ckad (⎈|minikube:mynamespace)]$ k get po NAME READY STATUS RESTARTS AGE mypod 0/1 ContainerCreating 0 4s nginx 1/1 Running 0 20m [k8s-ckad (⎈|minikube:mynamespace)]$ k exec -it mypod bash -- nginx -v nginx version: nginx/1.25.1 [k8s-ckad (⎈|minikube:mynamespace)]$ k describe pods mypod Name: mypod Namespace: mynamespace Priority: 0 Service Account: default Node: minikube/192.168.49.2 Start Time: Thu, 12 Oct 2023 17:33:46 +0900 Labels: run=mypod Annotations: <none> Status: Running IP: 172.17.0.4 IPs: IP: 172.17.0.4 Containers: mypod: Container ID: docker://147821ce3a12c57d9fef21026a57fcd0cee71360b411275db391a3dcccc25270 Image: nginx:1.25.1 Image ID: docker-pullable://nginx@sha256:67f9a4f10d147a6e04629340e6493c9703300ca23a2f7f3aa56fe615d75d31ca Port: 80/TCP Host Port: 0/TCP
Enter fullscreen mode Exit fullscreen mode

I hope this blog exercise has helped you.
Thank you

Top comments (0)