Basic in Windows

Links

Download the docker k8s from: https://docs.docker.com/desktop/vm-vdi/

img_node

Terms

- Node

A node is the smallest unit of computing hardware in Kubernetes.

- Cluster

The cluster as a whole, instead of worrying about the state of individual nodes.
AKA many node group as a cluster.

- Container

Just like Docker, a container references to a image.

- Pod

References to container, a Pod will contain various container like a pool. Also, a Node will contain multiples pods.

- AKA

Containers < Pod < Node < Cluster

- Namespace

Different development stages / area, e.g. dev, staging, production …
Flag is -n

img_terms

Commands

- View cluster info

CLI


# Check verion
kubectl version
 
# Check cluster
kubectl cluster-info
 
# Check pods
kubectl get pods
kubectl describe pods
 
# Check nodes
kubectl get nodes
 
# Check deployments status
kubectl get deployments

- Create a dummy samples

CLI


# kubectl create deployment <name> --image=<image_path>
kubectl create deployment kubernetes-bootcamp --image=gcr.io/google-samples/kubernetes-bootcamp:v1

- Open proxy

You need to open a second terminal window to run the proxy, for external connect.

CLI


kubectl proxy

- Get pod name

CLI


kubectl get pods
 
# NAME                                  READY   STATUS    RESTARTS   AGE
# kubernetes-bootcamp-f95c5b745-8zzfm   1/1     Running   0          21m
 
 
# The pod name is `kubernetes-bootcamp-f95c5b745-8zzfm`
 
# Using this can register the name to environment
export POD_NAME="$(kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}')"

- Go it pot

CLI


# Print env
kubectl exec "$POD_NAME" -- env
 
# Inside pod
kubectl exec -ti $POD_NAME -- bash

- Expose Your App (Create services)

We have to create a Service to expose the apps.

CLI


kubectl get pods
kubectl get services
 
# Create services
# kubectl expose deployment/<name> --type="NodePort" --port 8080
kubectl expose deployment/kubernetes-bootcamp --type="NodePort" --port 8080
 
kubectl get services
kubectl describe services/kubernetes-bootcamp
 
# In windows 10, you have to port forward the service to minikube
minikube service list
minikube service --url kubernetes-bootcamp
 
# If it's on other namespace
# minikube service <name> -n <namespace_name>
minikube service --url ingress-nginx-controller -n ingress-nginx

- Expose Your App (Pod open)

Testing a pod

CLI


# kubectl port-forward <pod_name> <Out_port>:<Inside_port>
kubectl port-forward nginx-pod 4000:80
 
# For delete
kubectl delete pod <name>
kubectl delete pod nginx-pod

- Rename Pod labels (inside variables)

CLI


kubectl describe deployment
 
# Print regarding info
kubectl get pods -l app=kubernetes-bootcamp
kubectl get services -l app=kubernetes-bootcamp
 
# Get name
export POD_NAME="$(kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}')"
echo "Name of the Pod: $POD_NAME"
 
# Set labels, set the "version" variables to "v1"
kubectl label pods "$POD_NAME" version=v1
 
# Print regarding info
kubectl describe pods "$POD_NAME"
kubectl get pods -l version=v1

- Deleting service

CLI


# kubectl delete service -l app=<name>
kubectl delete service -l app=kubernetes-bootcamp

- Deleting ingress

CLI


kubectl get ns 
 
# kubectl delete all --all -n <name>
kubectl delete all  --all -n ingress-nginx

- Scaling a Deployment

CLI


# Print regarding info
kubectl get deployments
 
# Get ReplicaSet
kubectl get rs
 
# Scale deployments
# kubectl scale deployments/<name> --replicas=<number>
kubectl scale deployments/kubernetes-bootcamp --replicas=4
 
# AKA replicas means the pod numbers to be desire
 
# View pods
kubectl get pods -o wide
kubectl describe deployments/kubernetes-bootcamp

- Endpoints

CLI


# Print regarding info
kubectl get endpoints
 
kubectl get pod -o wide

- Delete all stuff

CLI


kubectl delete deployment,service --all

- Create Ingress

CLI


minikube addons enable ingress
 
kubectl apply -f ingress.yaml
 
kubectl get ingress