hideojoho/0-from-zero-to-k8s-via-dockerhub.md

## 0-from-zero-to-k8s-via-dockerhub.md

      
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              0-from-zero-to-k8s-via-dockerhub.md
            
          
    From Zero to k8s via Docker Hub

GitHub -> Local -> Docker Hub -> GitHub -> Docker Hub -> k8s
Environment


Windows 10
WSL2 + Docker for Windows
VSCode
GitHub account
Docker Hub account

GitHub


Make a new repository

e.g., sample-svc


WSL


Start WSL
Clone the github repository
Open the repo folder from WSL with code sample-svc command

VSCode

The editor opens the repo folder within WSL.

Make index.html
Make Dockerfile
Open terminal in VSCode

Build a container

docker build -t username/sample-svc


Test a container


$ docker run -d -it --name svc username/sample-svc
$ docker exec svc /bin/sh -c "curl -s localhost"
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Sample Service</title>
  </head>
  <body>
    <h1>Sample Service</h1>
  </body>
</html>


Push to Docker Hub

$ docker push username/sample-svc


Commit to GitHub

$ git add .
$ git commit -m "Initial commit"
$ git push origin master

DockerHub


Go to the image build page

https://hub.docker.com/repository/docker/user-name/sample-svc/builds


Select GitHub from Automated Builds
Select Connect to GitHub from Linked Accounts

Give an authentication


Come back to the image build page again
Select GitHub (Connected) from Automated Builds
Select your account and repository (sample-svc) -> Save

VSCode


Change the title of index.html to Sample Microservice
Commit the change

$ git add .
$ git commit -m "Changed the title"
$ git push origin master

DockerHub


Check if the image is registered in the queue from the image build page
Wait until the image is successfully built

K8s


Make sample-svc.yaml

$ kubectl apply -f sample-svc.yaml
namespace/sample-svc unchanged
deployment.apps/sample-svc unchanged
service/sample-svc configured
$ kubectl get svc -A # Determine the internal port to which 80 is mapped
$ curl -s a-k8s-node:port
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Sample Microservice</title>
  </head>
  <body>
    <h1>Sample Service</h1>
  </body>
</html>

VSCode


Change the body text to Sample Microservice
Commit the change

Docker Hub


Wait until the new image is successfully built

k8s


Reload the image

$ kubectl rollout restart deployment sample-svc -n sample-svc
deployment.apps/sample-svc restarted
$ kubectl get svc -A # Same drill
$ curl -s a-k8s-node:port
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Sample Microservice</title>
  </head>
  <body>
    <h1>Sample Microservice</h1>
  </body>
</html>


Delete the whole thing

$ delete ns sample-svc


## 1-index.html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Sample Service</title>
  </head>
  <body>
    <h1>Sample Service</h1>
  </body>
</html>

## 2-Dockerfile
# Base Image
FROM  nginx:latest
# Maintainer
LABEL maintainer="you <you@example.com>"
# Add index.html to DocumentRoot
ADD index.html /usr/share/nginx/html

## 3-sample-svc.yaml
---
apiVersion: v1
kind: Namespace
metadata:
  name: sample-svc
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: sample-svc
  namespace: sample-svc
spec:
  selector:
    matchLabels:
      run: sample-svc
      app: sample-svc
  template:
    metadata:
      labels:
        run: sample-svc
        app: sample-svc
    spec:
      containers:
      - name: sample-svc
        image: username/sample-svc
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: sample-svc
  namespace: sample-svc
  labels:
    run: sample-svc
spec:
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
  selector:
    run: sample-svc
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<title>Sample Service</title>
	</head>
	<body>
	<h1>Sample Service</h1>
	</body>
	</html>
	# Base Image
	FROM nginx:latest
	# Maintainer
	LABEL maintainer="you <you@example.com>"
	# Add index.html to DocumentRoot
	ADD index.html /usr/share/nginx/html
	---
	apiVersion: v1
	kind: Namespace
	metadata:
	name: sample-svc
	---
	apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
	kind: Deployment
	metadata:
	name: sample-svc
	namespace: sample-svc
	spec:
	selector:
	matchLabels:
	run: sample-svc
	app: sample-svc
	template:
	metadata:
	labels:
	run: sample-svc
	app: sample-svc
	spec:
	containers:
	- name: sample-svc
	image: username/sample-svc
	ports:
	- containerPort: 80
	---
	apiVersion: v1
	kind: Service
	metadata:
	name: sample-svc
	namespace: sample-svc
	labels:
	run: sample-svc
	spec:
	ports:
	- port: 80
	targetPort: 80
	protocol: TCP
	selector:
	run: sample-svc