Run Nodejs Application in Kubernetes minikube

Table of Contents

• Prerequisite
• Build your Docker image locally
• Push your docker image to DockerHub
• Start the minikube
• Create Kubernetes Deployment resource
• Create deployment in Kubernetes
• Create Kubernetes service
• Create service in Kubernetes
• Get Kubernetes Service Details
• Accessing the service
• References

we have a dockerized NodeJS application and we will try to run that application in Minikube (Kubernetes)

Prerequisite

• Nodejs application which can be dockerized.
• Dockerize your Nodejs application
• Minikube should be installed on your machine
• Blog : Minikube installation
• YouTube : Minikube installation
• Kubectl should be installed on your machine
• Blog: Kubectl installation
• YouTube: Kubectl installation
• Dockerhub connectivity from your local machine
• Blog: Push your docker image to DockerHub

Build your Docker image locally

we are using the Nodejs sample app so we will give the name to the docker image as selftuts/node-sample-app

• selftuts is my DockerHub username. you need to put your DockerHub username.
• node-sample-app is the image name that will be published to DockerHub and other people will pull using this name
• If you check the Dockerfile then you will find that Docker container will expose port 9005 to the external world

docker build -t selftuts/node-sample-app .

Push your docker image to DockerHub

once you have created the docker image locally then you need to publish the image to DockerHub.

When we do the pod deployment in Minikube then we need to download the docker image. This image will be downloaded from DockerHub so we need to push the image to DockerHub

docker push selftuts/node-sample-app

Start the minikube

minikube start

Create Kubernetes Deployment resource

For deploying the pod in Kubernetes we need to create a Deployment resource file. Create a file as node-sample-app-deployment.yaml

Then using kubectl we can do the deployment in the Kubernetes cluster

apiVersion: apps/v1
kind: Deployment
metadata:
  name: node-sample-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: node-sample-app
  template:
    metadata:
      labels:
        app: node-sample-app
    spec:
      containers:
      - name: node-sample-app
        image: selftuts/node-sample-app:latest
        ports:
          - containerPort: 9005
        env:
          - name: PORT
            value: '9005'

Create deployment in Kubernetes

kubectl apply -f node-sample-app-deployment.yaml

This will create two things in Kubernetes

• Deployment
• Pod creation in Kubernetes

Fetch deployment using the below command

kubectl get deployments

➜ nodejs kubectl get deployments
NAME            READY  UP-TO-DATE  AVAILABLE    AGE
node-sample-app  1/1      1          1         2d15h

Fetch pods using the below command

kubectl get pods

➜ nodejs kubectl get pods
NAME                              READY    STATUS  RESTARTS    AGE
node-sample-app-5b7c68b964-4fpnm  1/1     Running    0        2d15h

Create Kubernetes service

When we create pods in the Kubernetes ecosystem then they are local to Kubernetes and are not accessible from outside.

we need to create a Kubernetes service that will point to those pods.

Create a node-sample-app-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: node-sample-app
spec:
  selector:
    app: node-sample-app
  type: LoadBalancer
  ports:
    - protocol: TCP
      port: 9005
      targetPort: 9005

Create service in Kubernetes

kubectl apply -f node-sample-app-service.yaml

Get Kubernetes Service Details

kubectl get service

➜ nodejs kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 443/TCP 9d
node-sample-app LoadBalancer 10.99.105.113 9005:32094/TCP 4s

Accessing the service

First, access the the Minikube IP

minikube ip

Then access the port which is binded with the external world

minikube service node-sample-app --url

References

• Minikube