> ## Documentation Index > Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt > Use this file to discover all available pages before exploring further. # Demo Deploying voting app on Kubernetes > This tutorial guides deploying a multi-tier voting application on In this tutorial, you will deploy a multi-tier voting application on a Minikube cluster. This guide explains step-by-step how to create the pod definition files for each application component and then expose them using Kubernetes services. *** ## Pod Definitions Start by creating a new project folder (e.g., "voting-app") and defining the pods for each component in separate YAML files. ### 1. Voting App Pod Create a file named `voting-app-pod.yaml`. This file specifies the API version, kind, metadata (including name and labels), and the container details. The labels group all the components as part of the same application while differentiating each component. ```yaml theme={null} apiVersion: v1 kind: Pod metadata: name: voting-app-pod labels: name: voting-app-pod app: demo-voting-app spec: containers: - name: voting-app image: kodekloud/example-voting-app:_vote-v1 ports: - containerPort: 80 ``` ### 2. Result App Pod Copy the voting app pod template to create the result app pod. Save it as `result-app-pod.yaml` and update the metadata (name, labels) and container details accordingly. ```yaml theme={null} apiVersion: v1 kind: Pod metadata: name: result-app-pod labels: name: result-app-pod app: demo-voting-app spec: containers: - name: result-app image: kodekloud/examplevotingapp_result:v1 ports: - containerPort: 80 ``` ### 3. Redis Pod For the Redis pod, create a file named `redis-pod.yaml`. Use the previous template and update the names accordingly. Note that the container port has been changed from 80 to 6379 (the default Redis port). ```yaml theme={null} apiVersion: v1 kind: Pod metadata: name: redis-pod labels: name: redis-pod app: demo-voting-app spec: containers: - name: redis image: redis ports: - containerPort: 6379 ``` ### 4. PostgreSQL (DB) Pod Using the Redis pod template, create the PostgreSQL pod definition file named `postgres-pod.yaml`. Update the pod and container names, use the official `postgres` image, and change the container port to 5432. Additionally, include environment variables for the initial username and password required by the worker and result pods. ```yaml theme={null} apiVersion: v1 kind: Pod metadata: name: postgres-pod labels: name: postgres-pod app: demo-voting-app spec: containers: - name: postgres image: postgres ports: - containerPort: 5432 env: - name: POSTGRES_USER value: "postgres" - name: POSTGRES_PASSWORD value: "postgres" ``` ### 5. Worker Pod Finally, create the worker pod in a file named `worker-app-pod.yaml`. Use the voting app pod template as a base but update the name and container properties to indicate background processing. Since the worker does not run any service or listen on ports, remove the container port definition. ```yaml theme={null} apiVersion: v1 kind: Pod metadata: name: worker-app-pod labels: name: worker-app-pod app: demo-voting-app spec: containers: - name: worker-app image: kodekloud/examplevotingapp_worker:v1 ``` *** ## Service Definitions After defining the pods, create the corresponding services to expose them. All components except the worker require external or internal services. ### 1. Redis Service (Internal) Create a file named `redis-service.yaml`. This service exposes the Redis pod on port 6379 internally, ensuring the selector matches the labels defined in the Redis pod. ```yaml theme={null} apiVersion: v1 kind: Service metadata: name: redis labels: name: redis-service app: demo-voting-app spec: ports: - port: 6379 targetPort: 6379 selector: name: redis-pod app: demo-voting-app ``` ### 2. PostgreSQL (DB) Service (Internal) Since the worker expects the Postgres service name to be "DB", create a file named `postgres-service.yaml`. This service exposes PostgreSQL on port 5432 and selects the appropriate pod. ```yaml theme={null} apiVersion: v1 kind: Service metadata: name: db labels: name: postgres-service app: demo-voting-app spec: ports: - port: 5432 targetPort: 5432 selector: name: postgres-pod app: demo-voting-app ``` ### 3. Voting App Service (External) To make the front-end voting app accessible externally, create a service named `voting-app-service.yaml`. Set the service type to `NodePort`, expose port 80, and assign a node port, such as 30004. Ensure that the selector matches the labels defined in the voting app pod. ```yaml theme={null} apiVersion: v1 kind: Service metadata: name: voting-service labels: name: voting-service app: demo-voting-app spec: type: NodePort ports: - port: 80 targetPort: 80 nodePort: 30004 selector: name: voting-app-pod app: demo-voting-app ``` ### 4. Result App Service (External) Similarly, create an external service for the result app. Save this file as `result-app-service.yaml`. This service is also set to type `NodePort`, exposing port 80 with a node port (e.g., 30005). Update the selector to match the result app pod. ```yaml theme={null} apiVersion: v1 kind: Service metadata: name: result-service labels: name: result-service app: demo-voting-app spec: type: NodePort ports: - port: 80 targetPort: 80 nodePort: 30005 selector: name: result-app-pod app: demo-voting-app ``` *** ## Deploying the Application With all five pod and service definition files created, navigate to your project directory (e.g., `voting-app`) and deploy each object using the `kubectl create -f` command. ```bash theme={null} # Create Pods kubectl create -f voting-app-pod.yaml kubectl create -f result-app-pod.yaml kubectl create -f redis-pod.yaml kubectl create -f postgres-pod.yaml kubectl create -f worker-app-pod.yaml # Create Services kubectl create -f redis-service.yaml kubectl create -f postgres-service.yaml kubectl create -f voting-app-service.yaml kubectl create -f result-app-service.yaml ``` Verify that all pods and services are active using: ```bash theme={null} kubectl get pods,svc ``` You should see all five pods running, with the voting and result services listed as NodePort services and the Redis and PostgreSQL (DB) services exposed as ClusterIP. To access the voting application, run: minikube service voting-service --url This opens the front-end interface where you can cast your vote. Once you cast a vote, check the results by accessing the result service: ```bash theme={null} minikube service result-service --url ``` This will display the updated voting results. The results page visually represents vote totals along with percentage breakdowns, enhancing the overall user experience. ![The image shows a split screen with equal blue and teal sections, displaying a 50% vote for both "CATS" and "DOGS."](https://kodekloud.com/kk-media/image/upload/v1752884953/notes-assets/images/Kubernetes-for-the-Absolute-Beginners-Hands-on-Tutorial-Demo-Deploying-voting-app-on-Kubernetes/frame_1170.jpg) ![The image shows a voting result with "Cats" at 0% and "Dogs" at 100% on a turquoise background.](https://kodekloud.com/kk-media/image/upload/v1752884955/notes-assets/images/Kubernetes-for-the-Absolute-Beginners-Hands-on-Tutorial-Demo-Deploying-voting-app-on-Kubernetes/frame_1210.jpg) *** ## Conclusion In this lesson, you successfully deployed a multi-tier voting application on a Kubernetes cluster. The architecture demonstrates the flow from the voting app pod to Redis, then through the worker pod to the PostgreSQL database, and finally to the result pod for display. This workflow highlights how to set up interconnected microservices using pods and services in Kubernetes. Happy deploying, and see you in the next tutorial!