deploy nodejs application to kubernetes

FROM node:17-alpine This line specifies the base image to use for the container.
WORKDIR /usr/src/app This line sets the working directory for the container to /usr/src/app This is where the application code and its dependencies will be copied to.
COPY package.json ./ This line copies the package.json file from the host machine to the /usr/src/app directory in the container. This file contains information about the application's dependencies, which will be installed in the next step.
RUN npm install This line runs the command npm install inside the container to install the dependencies listed in the package.json file.
COPY . . This line copies the rest of the application code from the host machine to the /usr/src/app directory in the container.
EXPOSE 3000 This line tells Docker that the container will listen on port 3000. This is the port that the application will be running on.
CMD ["node","index.js"] This line specifies the command to run when the container starts. In this case, it's running the command node index.js which starts the Node.js application.

Create a remote repository on Dockerhub. I named it examplerepo
Use the docker tag command to tag an image with a new name and push it to a remote repository. This will tag the image with a new name, and then push it to Docker Hub.

A deployment is responsible for creating, updating, and scaling pods, and rolling back to a previous version in case of a failure.

apps/v1, which is the version of the Kubernetes API used to create the deployment.
kind specifies that this is a deployment resource.
The deployment is named "nodeapp-deployment" and is labeled with "app: nodeapp". A label is a key-value pair that can be added to Kubernetes objects (such as pods, services, and deployments) to organize and identify them.
one replica of the pod should be running at all times.
The selector is used to determine which pods should be included in the deployment. The pods are selected based on the label "app: nodeapp".
The template defines the pod template that the deployment will use to create new pods.
The spec field of the template describes the container that runs inside the pod.
The container is named nodeserver, it uses the zainabmirkar1/nodeimage:latest image and containerPort is exposed on 3000

Services enable communication between pods within a cluster and also provide a stable endpoint for external clients to access the pods.

The service type is set to LoadBalancer, which means that the service will be exposed externally using a load balancer.
The service listens on port 5000, which is the port exposed by the load balancer, and forwards traffic to targetPort 3000 on the pods.
The nodePort field is set to 31110, which means that the service will also be exposed on that port on each node in the cluster.

Ensure Minikube is running by minikube status
kubectl apply -f deployment.yaml Kubernetes will read the YAML file and create or update the deployment according to the configuration specified in the file.

kubectl apply -f service.yaml Kubernetes will read the YAML file and create or update the service according to the configuration specified in the file