2021-08-26

Kubenetes Cheatsheet

Kubenetes notes from learning course: https://www.youtube.com/watch?v=X48VuDVv0do&t=2886s
Thanks TechWorld with Nana

Pre Requirements

minikube installed
kuberctl installed

Get nodes

~$ kubectl get nodes

NAME       STATUS   ROLES                  AGE   VERSION
minikube   Ready    control-plane,master   47h   v1.21.2

Create deployment using nginx dockerhub image

1	~$ kubectl create deployment nginx-deployment --image=nginx

Get deployment

~$ kubectl get deployment

NAME               READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   1/1     1            1           57s

Get pod

~$ kubectl get pod

NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-84cd76b964-lx2zk   1/1     Running   0          101s

Edit deployment config file

1
2
3

kubectl edit deployment nginx-deployment

You will see one auto-generated config file for this deployment, you can update image, replicas and others, it will auto apply by kubernates

Update replicas to 2

After few seconds the new pod will be created and STATUS become running

~$ kubectl get pods
NAME                                READY   STATUS              RESTARTS   AGE
nginx-deployment-84cd76b964-bk8pc   0/1     ContainerCreating   0          4s
nginx-deployment-84cd76b964-lx2zk   1/1     Running             0          6m57s

~$ kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-84cd76b964-bk8pc   1/1     Running   0          38s
nginx-deployment-84cd76b964-lx2zk   1/1     Running   0          7m31s

Show pod logs

1	kubectl get logs nginx-deployment-84cd76b964-lx2zk

Delete deployment

1	kubectl delete deployment nginx-deployment

kubectl apply yaml file

nginx-depl.yaml file

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-depl
  labels:
    app: nginx-depl
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx-depl
  template:
    metadata:
      labels:
        app: nginx-depl
    spec:
      containers:
      - image: nginx
        name: nginx
        ports:
        - containerPort: 80

1	kubectl apply -f nginx-depl.yaml

Kubenetes configuration file

metedata
specification
status - addtional, will be auto generated and controled by kubenetes

install hyperhit and minikube

brew update

brew install hyperkit

brew install minikube

kubectl

minikube

create minikube cluster

minikube start --vm-driver=hyperkit

kubectl get nodes

minikube status

kubectl version

delete cluster and restart in debug mode

minikube delete

minikube start --vm-driver=hyperkit --v=7 --alsologtostderr

minikube status

kubectl commands

kubectl get nodes

kubectl get pod

kubectl get services

kubectl create deployment nginx-depl --image=nginx

kubectl get deployment

kubectl get replicaset

kubectl edit deployment nginx-depl

debugging

kubectl logs {pod-name}

kubectl exec -it {pod-name} -- bin/bash

create mongo deployment

kubectl create deployment mongo-depl --image=mongo

kubectl logs mongo-depl-{pod-name}

kubectl describe pod mongo-depl-{pod-name}

delete deplyoment

kubectl delete deployment mongo-depl

kubectl delete deployment nginx-depl

create or edit config file

vim nginx-deployment.yaml

kubectl apply -f nginx-deployment.yaml