curl -sfL https://get.k3s.io | sh -

Check for ready node

sudo k3s kubectl get node

Kubectl

** If K3S is installed, installation of Kubectl is not necessary.

Download kubctl binary

To download latest release:

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

or for specific version:

curl -LO https://dl.k8s.io/release/v1.27.0/bin/linux/amd64/kubectl

Download checksum and validate kubectl binary

curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"
echo "$(cat kubectl.sha256)  kubectl" | sha256sum --check

Install kubectl

sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl

Simple usages

Run a docker container for one time only

kubectl run -it --rm --image=docker-image-name:version --restart=Never container-name -- [command-to-run]

Run a single-instance stateful application

For full details, please refers to Kubernetes documentation.

Configurations

mysql-pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: mysql-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi

mysql-deployment.yaml

apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  ports:
  - port: 3306
  selector:
    app: mysql
  clusterIP: None
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql:5.6
        name: mysql
        env:
          # Use secret in real usage
        - name: MYSQL_ROOT_PASSWORD
          value: password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim

Deploy MySQL and PersistentVolumnClaim

kubectl apply -f https://k8s.io/examples/application/mysql/mysql-pv.yaml
kubectl apply -f https://k8s.io/examples/application/mysql/mysql-deployment.yaml

Retrieve information on deployment

kubectl describe deployment mysql
kubectl get pods -l app=mysql
kubectl describe pvc mysql-pv-claim

Access MySQL instance

kubectl run -it --rm --image=mysql:5.6 --restart=Never mysql-client -- mysql -h mysql -ppassword

Delete deployment

kubectl delete deployment,svc mysql
kubectl delete pvc mysql-pv-claim
kubectl delete pv mysql-pv-volume

Port forwarding

Check the service is created

kubectl get service service-name

Verify pod is running and listening on port

kubectl get pod pod-name --template='{{(index (index .spec.containers 0).ports 0).containerPort}}{{"\n"}}'

Forward a local port to a port on the Pod

kubectl port-forward pod-name external-port:internal-port

For example with MySQL instance created in previous section,

kubectl port-forward mysql 3306:3306

Kubernetes Dashboard

Documentation

Installation

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

Create a service account

dashboard-adminuser.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard

Create service account

kubectl apply -f dashboard-adminuser.yaml

Create a ClusterRoleBinding

dashboard-clusterrolebinding.yaml

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard

Create ClusterRoleBinding

kubectl apply -f dashboard-clusterrolebinding.yaml

Run proxy to access dashboard

kubectl proxy --port=8080

can acccess at http://localhost:8080/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/

If accessing from outside of the machine is required, should supply address and accept-hosts arguments, but it requires SSL connection which is outside of the scope and please refer to documentation to enable HTTPS. Or use SSH tunnelling to access via HTTP.

kubectl proxy --address='0.0.0.0' --port=8002 --accept-hosts='.*'

*** The reason the port is set specifically to 8080 is to run k9s.

Create a bearer token

To log in to the Kubernetes dashboard, "Token" option should be selected and enter the token key generated from the following command.

kubectl -n kubernetes-dashboard create token admin-user

k9s

Installation

For ArchLinux

pacman -S k9s

or download from releases page and extract the binary

Running

k9s [-n namespace]

Commands

Refers https://k9scli.io/topics/commands/

Helm

Installation

curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3
chmod 700 get_helm.sh
./get_helm.sh

Usage

Add repo

helm repo add repo-name https://repo-url

Search package

helm search repo repo-name [package-name]

Install package

helm install name package-name

KubeVirt

Installation

Deploy KubeVirt operator

export VERSION=$(curl -s https://api.github.com/repos/kubevirt/kubevirt/releases | grep tag_name | grep -v -- '-rc' | sort -r | head -1 | awk -F': ' '{print $2}' | sed 's/,//' | xargs)
echo $VERSION
kubectl create -f https://github.com/kubevirt/kubevirt/releases/download/${VERSION}/kubevirt-operator.yaml

If nested virtualization cannot be enabled do enable KubeVirt emulation

kubectl -n kubevirt patch kubevirt kubevirt --type=merge --patch '{"spec":{"configuration":{"developerConfiguration":{"useEmulation":true}}}}'

Deploy KubeVirt custom resource definition

kubectl create -f https://github.com/kubevirt/kubevirt/releases/download/${VERSION}/kubevirt-cr.yaml

Verify components

deployement

kubectl get kubevirt.kubevirt.io/kubevirt -n kubevirt -o=jsonpath="{.status.phase}"

compoents

kubectl get all -n kubevirt

Virtctl

VERSION=$(kubectl get kubevirt.kubevirt.io/kubevirt -n kubevirt -o=jsonpath="{.status.observedKubeVirtVersion}")
ARCH=$(uname -s | tr A-Z a-z)-$(uname -m | sed 's/x86_64/amd64/') || windows-amd64.exe
echo ${ARCH}
curl -L -o virtctl https://github.com/kubevirt/kubevirt/releases/download/${VERSION}/virtctl-${VERSION}-${ARCH}
chmod +x virtctl
sudo install virtctl /usr/local/bin

Refers https://kubevirt.io/labs/kubernetes/lab1 for how to use Virtctl. And https://kubevirt.io/user-guide/virtual_machines/virtual_machine_instances/ on more in-depth into creation of virtual machines.

terrayi/run-kubernetes

Check for ready node

Download kubctl binary

Download checksum and validate kubectl binary

Install kubectl

Simple usages

Run a docker container for one time only

Run a single-instance stateful application

Configurations

mysql-pv.yaml

mysql-deployment.yaml

Deploy MySQL and PersistentVolumnClaim

Retrieve information on deployment

Access MySQL instance

Delete deployment

Port forwarding

Check the service is created

Verify pod is running and listening on port

Forward a local port to a port on the Pod

Create a service account

dashboard-adminuser.yaml

Create service account

Create a ClusterRoleBinding

dashboard-clusterrolebinding.yaml

Create ClusterRoleBinding

Run proxy to access dashboard

Create a bearer token

Running

Commands

Add repo

Search package

Install package

Installation

Deploy KubeVirt operator

If nested virtualization cannot be enabled do enable KubeVirt emulation

Deploy KubeVirt custom resource definition

Verify components

Virtctl