Hello Kubernetes!

This project is a fork of https://github.com/paulbouwer/hello-kubernetes adapted for the Plenus Cloud https://plenus.cloud

This container image is intended to be deployed into Plenus Cloud in a new namespace as an example application.

When accessed via a web browser via the chosen hostname, it will display:

• a default Hello from Plenus! message
• the pod name
• node os information

The default "Hello from plenus!" message displayed can be overridden using the MESSAGE environment variable. The default port of 8080 can be overriden using the PORT environment variable.

DockerHub

It is available on DockerHub as:

• plenus/hello-plenus:1.0

Deploy

Standard Configuration (http)

Customize the ingress hostname in yaml-http/hello-ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: hello-plenus
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  backend:
    serviceName: hello-plenus
    servicePort: 80
  rules:
  - host: my.wonderfulcloudapp.com
    http:
      paths:
      - backend:
          serviceName: hello-plenus
          servicePort: 80
        path: /

Change my.wonderfulcloudapp.com to the hostname you want to use to access the application. You will need to create a CNAME record for this name pointing to the name given by the Plenus Cloud for your namespace/cluster.

Deploy to your Kubernetes cluster using the yaml files in yaml-common/ and yaml-http/ directories Objects will be deployed to your current namespace defined in your context

kubectl apply -f yaml-common/
kubectl apply -f yaml-http/

Or by using script:

./deploy-http.sh

This will display a Hello from Plenus! message when you hit the ingress endpoint in a browser.

Ingress with Let's Encrypt certificate (https)

The https example will create an ingress that request a certificate from let's encrypt using cert-manager preinstalled in the cluster. There is a default cluster-issuer that will authorize the certificate using HTTP01 challenge.

Customize the ingress hostname in yaml-https/hello-ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: hello-plenus
  annotations:
    kubernetes.io/ingress.class: "nginx"
    kubernetes.io/tls-acme: "true"
spec:
  backend:
    serviceName: hello-plenus
    servicePort: 80
  rules:
  - host: my.wonderfulcloudapp.com
    http:
      paths:
      - backend:
          serviceName: hello-plenus
          servicePort: 80
        path: /
  tls:
  - hosts:
    - my.wonderfulcloudapp.com
    secretName: hello-plenus-tls

for the https version you will need to change the hostname twice: in the rules and tls sections.

Change my.wonderfulcloudapp.com to the hostname you want to use to access the application. You will need to create a CNAME record for this name pointing to the name given by the Plenus Cloud for your namespace/cluster. Important: if you deploy the application before the dns record has been propagated let's encrypt authorization could fail, if this happens certificate generation could take a longer time (up to 1 hour + dns propagation time).

Deploy to your Kubernetes cluster using the yaml files in yaml-common/ and yaml-https/ directories Objects will be deployed to your current namespace defined in your context

kubectl apply -f yaml-common/
kubectl apply -f yaml-https/

Or by using script:

./deploy-https.sh

After deployment you can check certificate status with command :

kubectl get certificate hello-plenus-tls -oyaml

When the certificate is ready the status will be similar to:

apiVersion: cert-manager.io/v1alpha2
kind: Certificate
metadata:
  creationTimestamp: "2020-08-28T12:33:04Z"
  generation: 2
  name: hello-plenus-tls
  namespace: my-first-app-03eb
  ownerReferences:
  - apiVersion: extensions/v1beta1
    blockOwnerDeletion: true
    controller: true
    kind: Ingress
    name: hello-plenus
    uid: db2dd3e6-6756-40f3-b164-0c7fc3f0660e
  resourceVersion: "63116415"
  selfLink: /apis/cert-manager.io/v1alpha2/namespaces/my-first-app-03eb/certificates/hello-plenus-tls
  uid: 730b6a58-749e-440d-8253-467480ba1919
spec:
  dnsNames:
  - my.wonderfulcloudapp.com
  issuerRef:
    group: cert-manager.io
    kind: ClusterIssuer
    name: letsencrypt
  secretName: hello-plenus-tls
status:
  conditions:
  - lastTransitionTime: "2020-08-28T12:34:39Z"
    message: Certificate is up to date and has not expired
    reason: Ready
    status: "True"
    type: Ready
  notAfter: "2020-11-26T11:34:38Z"

Cleaning Up

You can delete deployed objects with command (http version):

./delete-http.sh

Use delete-https.sh to clean up https example.

Build Container Image

If you'd like to build the image yourself, then you can do so as follows. The build-arg parameters provides metadata as defined in OCI image spec annotations.

Bash

$ docker build --no-cache --build-arg IMAGE_VERSION="1.8" --build-arg IMAGE_CREATE_DATE="`date -u +"%Y-%m-%dT%H:%M:%SZ"`" --build-arg IMAGE_SOURCE_REVISION="`git rev-parse HEAD`" -f Dockerfile -t "hello-kubernetes:1.8" .

Powershell

PS> docker build --no-cache --build-arg IMAGE_VERSION="1.8" --build-arg IMAGE_CREATE_DATE="$(Get-Date((Get-Date).ToUniversalTime()) -UFormat '%Y-%m-%dT%H:%M:%SZ')" --build-arg IMAGE_SOURCE_REVISION="$(git rev-parse HEAD)" -f Dockerfile -t "hello-kubernetes:1.8" .

Develop Application

If you have VS Code and the Visual Studio Code Remote - Containers extension installed, the .devcontainer folder will be used to build a container based node.js 13 development environment.

Port 8080 has been configured to be forwarded to your host. If you run npm start in the app folder in the VS Code Remote Containers terminal, you will be able to access the website on http://localhost:8080. You can change the port in the .devcontainer\devcontainer.json file under the appPort key.

See here for more details on working with this setup.