Project 8 → Three tier application deployment on Kubernetes

Aakib
12 min readJan 26, 2024

This is the 8th project in our series let’s follow on

what do you mean by three tier ?

It’s actually a division of your system in 3 parts

  1. Presentation Layer (Tier 1):
  • What you you see when you open your website is called the presentation layer basically it is the layer that users interact directly

2. Logical Layer (Tier 2):

  • Imagine this layer as the brain behind the scenes. It takes the information you provide through the user interface and processes it according to the rules of the system. If it’s a shopping website, for instance, this layer figures out things like the total price of your items, applies discounts, and checks if everything is in stock

3. Data Layer (Tier 3):

  • This is where the data is stored and retrieved. It’s like the memory of the system.
  • Data could be stored in databases, files, or any other data storage systems.
  • The data layer is responsible for managing and storing information that the system needs.
let’s deploy the application

Completion Steps →

Phase 1 →Setup base EC2 , IAM user and Basic tools on EC2

Phase 2 →Built frontend and backend images

Phase 3 → Kubernetes

Phase 4 →Setup Application Load balancer and ingress

Phase 5 →Destroy Everything

Phase 1 →Setup base EC2 , IAM user and Basic tools on EC2

Step 1. Create an IAM user

click on iam

2. click on user →create user

3. Give a name to your user and tick on provide user access to management console and then click on I want an IAM user option

5. choose a password for your user →click next

6. Attach the policies directly to your iam user → click next

note →I will provide the administrator accesss for now but we careful while attaching the policies at your workapce

review and create user

7. click on create user

8. download your password file if it is autogenerated otherwise it is your’s choice

9. Now click on your IAM user →security credentials

10. scroll down to access keys and create an access keys

11.choose aws cli from the options listed

12. click next and download you csv file for username and password

Step 2. launching a base EC2 where we do all work →

  1. open your aws console and navigate to ec2 and click on launch ec2

2. Click on connect and run the following commands

sudo su
apt update
mkdir 3-tier
cd 3-tier

3. fetch the code from github by git clone

git clone https://github.com/Aakibgithuber/Three-tier-Application-Deployment-.git

4. Run ls to see the what is inside the repo

Step 3 →Setup aws cli ,docker ,kubectl and eksctl

1. configuring aws cli

AWS CLI (Amazon Web Services Command Line Interface) is a tool that allows you to interact with AWS services using commands

  1. run the following commands to install aws cli
snap install aws-cli --classic

2. you have to configure aws by the command →

aws configure

3. It is asked for access key and secret key now you have to open that csv file you downloaded above and copy the access and secret key

4. Remain everything as it is and click enter

your aws cli is setup now setup docker

2. Setup docker

  1. run the following commands
apt install docker.io
usermod -aG docker $USER # Replace with your username e.g ‘ubuntu’
newgrp docker
sudo chmod 777 /var/run/docker.sock
which docker

3. setup kubectl

It is a command-line tool used in managing and interacting with Kubernetes clusters

  1. To install kubectl run the following commands
snap install kubectl --classic

4. setup eksctl

It is a command-line tool used for managing Amazon EKS (Elastic Kubernetes Service) clusters.

  1. To install eksctl tool run the following commands
curl --silent --location "https://github.com/weaveworks/eksctl/releases/latest/download/eksctl_$(uname -s)_amd64.tar.gz" | tar xz -C /tmp
sudo mv /tmp/eksctl /usr/local/bin
eksctl version

Phase 2 →Built frontend and backend images

Step 1 → setup Elastic container registery (ECR)

It is similiar to dockerhub where we stored the docker images

  1. Go to your aws console and search for ECR
  2. click on create repository for frontend and set visiblity setting to public

3. Setup backend Repository

Step 2 →Setup frontend

  1. In terminal go to frontend directory and run ls command

2. Go to your ecr repo and click on view push commands

3. Run the above command one by one to build the frontend image and push to ecr repository

aws ecr-public get-login-password --region us-east-1 | docker login --username AWS --password-stdin public.ecr.aws/l0l7e4u1
docker build -t 3-tier-frontend .
docker tag 3-tier-frontend:latest public.ecr.aws/l0l7e4u1/3-tier-frontend:latest
docker push public.ecr.aws/l0l7e4u1/3-tier-frontend:latest

4. Let’s run a container from the image

docker images -->copy the image name from the list 
docker run -d -p 3000:3000 3-tier-frontend:latest

your frontend has setup and your application is now running to see your application you could browse →public-ip:3000

Our application is runniong on port no. 3000

Step 3 →Setup backend

  1. Now go to backend directory to setup backend

2. Go to your ecr repo and click on view push commands of backend repo

3. run the above command one by one in your terminal

aws ecr-public get-login-password --region us-east-1 | docker login --username AWS --password-stdin public.ecr.aws/l0l7e4u1
docker build -t 3-tier-backend .
docker tag 3-tier-backend:latest public.ecr.aws/l0l7e4u1/3-tier-backend:latest
docker push public.ecr.aws/l0l7e4u1/3-tier-backend:latest

Now your backend imge is built successfully and also pushed to Elastic container registery which we used when we create elastic kubernetes service

Phase 3 Kubernetes

  1. What is Deployment:
  • Imagine a Factory: Think of a deployment as a factory that produces and manages copies of your software applications.
  • Multiple Replicas: Just like a factory can produce multiple identical items, a deployment in Kubernetes can create and handle multiple copies (replicas) of your application.
  • Easy Updates: If you want to change or update your application, the deployment system can smoothly handle that, like swapping out parts in a factory without stopping production.

2. what is Service:

  • Imagine a Reception Desk: Picture a service in Kubernetes like a reception desk in a building.
  • Central Point of Contact: The service provides a central point of contact for your applications. Instead of trying to find each application directly, other parts of your system can talk to the service, and it knows how to find the right application.
  • Stable Address: Just as you have a consistent address for the reception desk, a service has a stable address that other parts of your system can use to communicate with your applications.

3. What is Namesapce

  1. It’s like a labeled section within Kubernetes where you can organize and run your applications. Each namespace is like a fenced-off area where your apps can do their thing without stepping on each other’s toes.
  2. So, in simpler terms, a namespace in Kubernetes is a way to keep different projects or applications separate and organized, making it easier to manage them in the bustling environment of a Kubernetes cluster

Step 1 →Setup EKS Cluster and create a namespace

  1. Run the following command to setup EKS cluster
eksctl create cluster --name three-tier-cluster --region us-east-1 --node-type t2.medium --nodes-min 2 --nodes-max 2
aws eks update-kubeconfig --region us-east-1 --name three-tier-cluster
kubectl get nodes

2. It takes 15 to 20 mins to create a cluster

3.on aws console search for aws cloud formation to view the events happening in creation of EKS cluster

your two nodes is ready to go

4. creating Namesapce from the following command

kubectl create namespace workshop
kubectl config set-context --current --namespace workshop
your namesapce is created

Step 2→ create a deployment and service for Frontend

  1. go to k8s_manifests directory there you will find deployment and service files for frontend

2. you have to edit the file called frontend-deployment.yaml

3. one thing you need to be changed that is your image name

4. so, go to your ecr repo → select the frontend repo →click on view public listing and copy the image name and paste inside the frontend-deployment.yaml file

Now run the following commands to create the deployment and service for frontend

kubectl apply -f frontend-deployment.yaml
kubectl apply -f frontend-service.yaml

Step 3→ create a deployment and service for Backend

  1. In the same folder you will find backend-deployment.yaml and backend-service.yaml
  2. you have to edit the file called backend-deployment.yaml
  3. one thing you need to be changed that is your image name
  4. so, go to your ecr repo → select the backend repo →click on view public listing and copy the image name and paste inside the backend-deployment.yaml file

Now run the following commands to create the deployment and service backend

kubectl apply -f backend-deployment.yaml
kubectl apply -f backend-service.yaml
kubectl get pods -n workshop

Now our two tier is ready that is frontend and backend let’s setup the third tier

step 4 →Setup Database tier

  1. Locate the mongo folder that stores deployment , service and secrets manifests

2. Run the below commands to setup database tier

kubectl apply -f .
kubectl get all

Now your all three tiers are ready to go but how do you access them for that we have to create a application load balancer to route outside traffic towards cluster and an ingress for in internal routing between our 3 tiers

Phase 4 →Setup Application Load balancer and ingress

we have to create a application load balancer to route outside traffic towards cluster and an ingress for in internal routing between our 3 tiers

Step 1 →Setup aws load balancer ; installation and attachement it to your EKS cluster

1. Below command fetch the iam policy for your ALB

curl -O https://raw.githubusercontent.com/kubernetes-sigs/aws-load-balancer-controller/v2.5.4/docs/install/iam_policy.json

2. This command create the iam policy in your aws account from iam_policy.json file that is setup in the first command

aws iam create-policy --policy-name AWSLoadBalancerControllerIAMPolicy --policy-document file://iam_policy.json

3. This command apply the load balancer policy to your eks cluster so that your eks cluster is working with your load balancer according to the policy

eksctl utils associate-iam-oidc-provider --region=us-east-1 --cluster=three-tier-cluster --approve

4. This command create and attach an service account to your cluster so that your cluster is allowed to work with load balancer service

please change your aws account no. from the below command otherwise it won’t work

eksctl create iamserviceaccount --cluster=three-tier-cluster --namespace=kube-system --name=aws-load-balancer-controller --role-name AmazonEKSLoadBalancerControllerRole --attach-policy-arn=arn:aws:iam::767397866747:policy/AWSLoadBalancerControllerIAMPolicy --approve --region=us-east-1

All the policies are attached let’s deploy the load balancer

5. For this we have to install helm→Helm is a special tool that helps you easily carry and manage your software when you’re using Kubernetes, which is like a big playground for running applications.

sudo snap install helm --classic

6. After this we have to add a particular manifest for load balancer that is pre written by someone on eks repo by using helm

helm repo add eks https://aws.github.io/eks-charts

7. update the eks repo using helm

helm repo update eks

8. Install the load balancer controller on your eks cluster

helm install aws-load-balancer-controller eks/aws-load-balancer-controller -n kube-system --set clusterName=my-cluster --set serviceAccount.create=false --set serviceAccount.name=aws-load-balancer-controller
kubectl get deployment -n kube-system aws-load-balancer-controller

Now your Load balancer is working let’s setup Ingress for internal routing

Step 2 →Setup Ingress for internal routing

  1. Loacte the full_stack_lb.yaml file
kubectl apply -f full_stack_lb.yaml
kubectl get ing -n workshop

2. go to your Web Browser and paste the above dns address

Congrtas !! Your application is accessible through load balancer ingress

Phase 5 →Destroy Everything

  1. On your current folder run
kubectl delete -f .

2. go to mongo folder to delete database tier

kubectl delete -f .

3. Delete the cluster and the stack of your cloud formation

eksctl delete cluster --name three-tier-cluster --region us-east-1
aws cloudformation delete-stack --stack-name eksctl-three-tier-cluster-cluster

4. you could checkout alll the changes in cloud formation console of aws

Stack is also cleared

Everything is deleted now thanks me for reducing your aws bill

well our project is completed here if you comes at this point do clap and

follow me on linkedin

follow me on github

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Aakib

Cloud computing and DevOps Engineer and to be as a fresher I am learning and gaining experiance by doing some hands on projects on DevOps and in AWS OR GCP