Deploy Todo App on k8 cluster by Terraform

Recommendations:

• Go thought the project and run it.
• Be fearless and play with it.

What we'll do here -

1. Setup a AWS VPC with 4 subnets in 2 Availability Zone.
2. Configure IGW and NAT Gateway with route table.
3. Create a EKS Master cluster in public subnets and Worker in Private subnets.
4. Deploy Todo app with Java API, Angular UI and MySQL as Kubernetes resource.
5. And all we'll do just running terraform script.

• Finally access the app by a local domain pointing NLB's static IP

First 2 steps I already described in previous articles -

1. AWS VPC with Terraform | Part 1 (VPC)
2. Setting up AWS VPC using Terraform | Part 2 (Hands-on)

Clone github repository -

$ git clone https://github.com/hnjcode/deploy-todo-app-in-eks-vpc-by-terraform.git         

Previously we create the VPC, here we are going to create a AWS Elastic Kubernetes Service (EKS) cluster inside the VPC.

Elastic Kubernetes Service (EKS)

EKS is the Managed Kubernetes service in AWS cloud provider. Although you place your EKS Master Cluster in public subnets in your own VPC but actually its not part of your VPC. Just permit EKS Control Plane to control/communicate your EKS Cluster through this way. This is why EKS called as Managed Kubernetes service.

EKS Control Plane is the Master which is owned by AWS itself. When you create a EKS cluster in your account, AWS connect it to their EKS Control Plane of that region where you create your EKS.

EKS Worker Node Group is kept here in private subnets which are responsible to pull images, make the deployments (pods), expose services assigned by EKS Control Plane.

Check modules/eks codes for EKS and its dependent on 2 IAM role which you will find in modules/iam

Setup the Infrastructure

Run below command in project root directory

?? Alert: You must change the S3 bucket name and ensure such key path is available in your own bucket in backent.tf and k8-resources/backend.tf file.

$ terraform apply -var-file="prod.tfvars" -auto-approve        

It will setup VPC and EKS as prod environment.

Deploy Kubernetes Resources

After setting up AWS infrastructure successfully move to k8-resources and apply -

$ cd k8-resources

$ terraform apply -auto-approve        

If you check k8-resources you will find -

1. Read and access the EKS cluster as remote state.
2. Create a todo Kubernetes namespace.
3. Make 3 deployments by pulling todo-service, todo-service-ui and mysql image from docker hub.
4. Expose 3 services for their internal communication. Only todo-service-ui is publicly exposed by a AWS NLB. Others two are Cluster IP.

server {
    listen 80;
    server_name todo;

    location / {
        root /usr/share/nginx/html;
        index index.html;
        try_files $uri /index.html;
    }
    
    location /api/ {
        proxy_pass https://todo-service:8080;
        .
        .
        .
    }
}        

Since in Angular UI application is using nginx proxy so any call with /api it will pass to https://todo-service:8080 with adding endpoint since todo-service is the service to reach todo-api. Similarly todo-api will connect to mysql through its service.

Since your EKS already up and you successfully deployed k8 resources now add the EKS context in your local terminal -

$ aws eks --region us-west-1 update-kubeconfig --name eksdemo        

check pods and services by -

$ kubectl get pods -n todo

$ kubectl get svc -n todo        

I hope you are here after successfully deploying everything ... Now lets access the todo application with a domain. Run below command with your actual AWS NLB domain which you have seen previously while running kubectl get svc -n todo and get the static public IP

$ nslookup paste-your-aws-nlb-domain-url        

Now add the IP in your /etc/hosts files like - (Don't forget to paste your NLB IP)

 52.53.123.136 todo        

Previously You have seen I added server_name todo; in ui image nginx configuration which means the ui application will serve if you in your browser by https://todo and you will see ...

THE END