Docker create image and run with Kubernetes

Docker

1. Create a test Nodes.js app.js

const http = require('http');
const os = require('os');
console.log("Tellhost server starting...");
const handler = function(request, response) {
	console.log("Received request from " + request.connection.remoteAddress);
	response.writeHead(200);
	response.end("You've hit " + os.hostname() +" from " + request.connection.remoteAddress+ "\n");
};
const www = http.createServer(handler);
www.listen(8080);

1. create Dockerfile

FROM node:16
ADD app.js /app.js
ENTRYPOINT ["node", "app.js"]

1. Directory structure

--
 -- app.js
 -- Dockerfile

1. Create Docker Image
   docker build -t tellhost . Run this command in the same directory with Dockerfile
2. Show all images
   docker images
3. Run the image
   docker run --name tellhost-container -p 8080:8080 -d tellhost

-d: The container will be detached from the console (-d flag), which means it will
run in the background.
-p 8080:8080 map 8080 on local machine to 8080 inside the container

1. show all running containers
   docker ps
docker ps -a show all running and stopeed
2. Show the detail of one container
   docker inspect tellhost-container
3. Run bash shell inside the container
   docker exec -it tellhost-container bash

-i, which makes sure STDIN is kept open. You need this for entering commands into the shell.
-t, which allocates a pseudo terminal (TTY).

1. Stop container
   docker stop tellhost-container
2. Remove container
   docker remove tellhost-container

Kubernetes

1. show server status
   kubectl cluster-info
2. show all nodes
   kubectl get nodes
3. show detail of one node
   kubectl describe node your-node-name
4. run one image
   kubectl run tellhost --image toka9988/tellhost --port=8080
   It doesn't map the port on local machine.So you need to login the container.
5. expose the pod
   kubectl expose pod tellhost --type=LoadBalancer --name tellhost-http
6. deploy application
   kubectl create deployment tellhost2 --image=toka9988/tellhost
7. expose deployment
   kubectl expose deployment tellhost2 --type=LoadBalancer --port 8080
8. show all deployment
   kubectl get deployments
9. show all pods
   kubectl get pods
10. scale out
    kubectl scale deployment tellhost2 --replicas=3
11. show pod's detail
    kubectl describe pod your-pod-name
12. show services
    kubectl get services