DigitalOcean Kubernetes Challenge 2021

This repository is created for DigitalOcean Kubernetes Challenge 2021.

Roadmap

• Build a demo Ruby on Rails API Server
• Create a Kubernetes Cluster in DigitalOcean
• Create a scalable database on Kubernetes
• Import example data to demo application

Detail

This is Viewshow crawler as an API service for demo.

Demo URL: https://kube-challenge.aotoki.dev/

Create Namespace

kubectl apply -f namespaces.yml

Create Secrets

To create the database for the application, we need to set up PostgreSQL.

# secrets/postgres.yml
apiVersion: v1
kind: Secret
metadata:
  name: cinema-database-secret
  namespace: cinema
type: Opaque
stringData:
  superUserPassword: [PASSWORD]
  replicationUserPassword: [PASSWORD]

In this demo, the super password will be used for the application. Don't use it in a production application.

kubectl apply secrets/postgres.yml

Add DATABASE_URL as secret for application

apiVersion: v1
kind: Secret
metadata:
  name: cinema-secret
  namespace: cinema
type: Opaque
stringData:
  DATABASE_URL: postgres://postgres:[PASSWORD]@cinema-db.cinema.svc.cluster.local/cinema

Setup Kubegres

Install Kubegres

kubectl apply -f https://raw.githubusercontent.com/reactive-tech/kubegres/v1.14/kubegres.yaml

Crreate Database in cinema namespace

kubectl apply -f databases/cinama.yml

Create database use createdb command in local machine

kubectl port-forward -n cinema service/cinema-db 5678:5432

Setup Cert-Manager for Let's Encrypt

Install Cert-Manager via Helm

helm repo add jetstack https://charts.jetstack.io
helm repo update
helm install \
  cert-manager jetstack/cert-manager \
  --namespace cert-manager \
  --create-namespace \
  --version v1.6.1 \
  --set installCRDs=true

Configure issuer

kubectl apply -f issuer.yml

The email is masked, changed it before run the command

Setup Application

Deploy application

kubectl apply -f deployments/cinema.yml

Create service

kubectl apply -f services/cinema.yml

Configure Ingress

kubectl apply -f ingress/cinema.yml

Add CronJob to refresh movies

kubectl apply -f jobs/cinema.yml

Trigger CronJob to initialize data

kubectl create job -n cinema --from=cronjob/cinema-refresh cinrma-movies-init

Test API

curl https://kube-challenge.aotoki.dev/