Kubernetes

1. https://minikube.sigs.k8s.io/docs/start/: install minikube

2. Need to download & install docker desktop for Mac : https://docs.docker.com/desktop/install/mac-install/

3. To start minikube : minikube start

4.  kubectl exec -ti $POD_NAME -- bash

5. kubectl exec -it hello-node-57c8dd9df8-pvtj8 curl localhost:8080

6.apt-get update

apt-get install net-tools

curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/k8s.gpg

curl https://download.webmin.com/jcameron-key.asc | gpg --dearmor | sudo tee /usr/share/keyrings/jcameron-key.gpg > /dev/null 2>&1 

 apt install -y curl gnupg2 software-properties-common apt-transport-https ca-certificates 

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - 

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" 

https://upcloud.com/resources/tutorials/install-kubernetes-cluster-centos-8

To connect external internet: kubectl proxy

 curl http://localhost:8001/version

export POD_NAME=$(kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}')

curl http://localhost:8001/api/v1/namespaces/default/pods/$POD_NAME/     

kubectl run hello-world --image us.icr.io/$MY_NAMESPACE/hello-world:1 --overrides='{"spec":{"template":{"spec":{"imagePullSecrets":[{"name":"icr"}]}}}}'

kubectl config get-contexts

Minikube:

Docker Desktop networking doesn't support ports. You will have to use minikube tunnel

minikube start --driver=docker --extra-config=apiserver.service-node-port-range=32760-32767 --ports=127.0.0.1:32760-32767:32760-32767

minikube start --ports=port-target:node-port

for eg; minikube start --ports=30390:30390

Enter container : kubectl exec -it $POD_NAME -- bash

System namespace pods:

kubectl get po -n kube-system

minikube start --driver=docker

export NO_PROXY=localhost,127.0.0.1,10.96.0.0/12,192.168.59.0/24,192.168.49.0/24,192.168.39.0/24

Question: how to setup service

1. Kubectl proxy
2. kubectl expose deployment/kubernetes-bootcamp --type="NodePort" --port 8080
3. kubectl   port-forward.  kubernetes-demo-pod 3000:3000

$ minikube service my-deployment-service --url

http://192.168.99.100:30390

Test curl working or not:

$ kubectl run -i --tty alpine --image=alpine --restart=Never -- sh

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube

  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

kubectl expose deployment hello-world --type=LoadBalancer --name=my-service

kubectl port-forward kubernetes-dashboard-7798c48646-ctrtl 8443:8443 --namespace=kube-system

Dashboard setup:

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.7.0/aio/deploy/recommended.yaml

Kubectl proxy

http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/

https://securitybank.atlassian.net/wiki/spaces/ODP/overview

kubectl port-forward pod/foo 8080:8080

kubectl apply -f pod.yaml,service.yaml

kubectl  delete  -f pod.yaml,service.yaml

kubectl run -i --tty alpine --image=alpine --restart=Never -- sh

kubectl create -f pod.yaml 

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/darwin/arm64/kubectl"

Https://dl.k8s.io/release/$(v1.26.3)/bin/darwin/arm64/kubectl

db.createUser({ user:'admin',pwd:'123456',roles:[ { role:'userAdminAnyDatabase', db: 'admin'},"readWriteAnyDatabase"]});

docker run --name=mk-mysql -p3306:3306 -v mysql-volume:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=password -d mysql/mysql-server:8.0.20

GRANT ALL PRIVILEGES ON database_name.* TO ‘root’@’172.17.0.2’;

docker run \

  --name jenkins-docker \

  --detach \

  --privileged \

  --network jenkins \

  --network-alias docker \

  --env DOCKER_TLS_CERTDIR=/certs \

  --volume jenkins-docker-certs:/certs/client \

  --volume jenkins-data:/var/jenkins_home \

  --publish 2376:2376 \

  --publish 3000:3000 --publish 5000:5000 \

  --restart=on-failure \

  docker:dind \

  --storage-driver overlay2 

docker run \

  --name jenkins-blueocean \

  --detach \

  --network jenkins \

  --env DOCKER_HOST=tcp://docker:2376 \

  --env DOCKER_CERT_PATH=/certs/client \

  --env DOCKER_TLS_VERIFY=1 \

  --publish 8080:8080 \

  --publish 50000:50000 \

  --volume jenkins-data:/var/jenkins_home \

  --volume jenkins-docker-certs:/certs/client:ro \

  --volume "$HOME":/home \

  --volume /var/run/docker.sock:/var/run/docker.sock \

  --restart=on-failure \

  --env JAVA_OPTS="-Dhudson.plugins.git.GitSCM.ALLOW_LOCAL_CHECKOUT=true" \

  myjenkins-blueocean:2.375.2-1 

OpenShift

To login : oc login -u admin -p admin https://api.crc.testing:6443 --insecure-skip-tls-verify=true

export POD_NAMe=$(kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}')

How to setup Kubernetes cluster in Ubuntu 20.04

1. For my machine, i need to add 3 lines to my .bashrc

export KUBECONFIG=/etc/kubernetes/admin.conf

swapoff -a

ufw disable

P.S. otherwise will always receive : kubectl connection refused, did you specify the right host or port

 Learn Kubernetes: https://kubernetes.io/docs/tutorials/kubernetes-basics/

Minikube: https://minikube.sigs.k8s.io/docs/

Docker playground: https://labs.play-with-docker.com/

Youtube kubernetes: https://www.youtube.com/watch?v=X48VuDVv0do&t=2273s

Docker images repository: https://hub.docker.com/search?q=

Lab for Kubernetes : https://collabnix.github.io/kubelabs/kube101.html

                                  https://killercoda.com/playgrounds/scenario/kubernetes

Kubernetes classroom : https://training.play-with-kubernetes.com/kubernetes-workshop/