Deploying a Node.js Application with Docker and Kubernetes

Hey there! Today, I want to share my experience of deploying a Node.js application using Docker and Kubernetes. It was quite a journey, and I learned a lot along the way. If you’re looking to do something similar, I hope this step-by-step guide helps you out!

What You’ll Need

Before we dive in, make sure you have the following tools installed on your machine:

• Docker: For containerizing our application.

• Kubernetes: I used Kind, but you can use any local setup you prefer.

• kubectl: The command-line tool for interacting with Kubernetes.

• Git: To clone the project repository.

Step 1: Setting Up the Project

First things first, I created a directory for my project. Here’s how I did it:

mkdir k8s-production
cd k8s-production

Next, I cloned my Node.js application repository. Just replace <repository-url> with your actual repo URL:

git clone https://github.com/mansurianas/node-phontiqe.git
cd node-phontiqe

Docker File

# Use a lightweight Node.js image
FROM node:alpine

# Set the working directory inside the container
WORKDIR /app

# Copy only the necessary files for npm install
COPY . .
COPY package*.json ./

# Install dependencies
RUN npm install

# Copy the rest of the application files
COPY . .
#copy  the public directory to the root
COPY ./client/public /public
# Expose the port the app will run on
EXPOSE 3000

# Command to run the application
CMD ["node", "server.js"]

Step 2: Logging into Docker

Before I could push my Docker image, I needed to log in to my Docker account. This is super easy:

docker login

Just enter your credentials, and you’re good to go!

Step 3: Building the Docker Image

Now it was time to build the Docker image for my Node.js app. I made sure I had a Dockerfile in my project directory, and then I ran:

docker build -t anas011/nodejs:latest .

This command builds the image and tags it as anas011/nodejs:latest.

docker run -p 3000:3000 anas011/nodejs:latest

Step 4: Tagging the Docker Image

After building the image, I needed to tag it for my Docker Hub repository. Here’s the command I used:

docker image tag anas011/nodejs:latest lucky0111/nodejs:latest

Step 5: Pushing the Docker Image

With the image tagged, it was time to push it to Docker Hub. I ran:

 push lucky0111/nodejs:latest

I was excited to see the output showing that my image layers were being pushed:

The push refers to repository [docker.io/lucky0111/nodejs]
f5e2a07ec7c2: Pushed
70e7c4b7ec0c: Pushed
...
latest: digest: sha256:...

Step 6: Creating Kubernetes Configurations

Next, I created a directory for my Kubernetes configuration files:

 k8s
cd k8s

Deployment Configuration

I created a file named deployment.yml with the following content:

kind: Deployment
apiVersion: apps/v1
metadata:
  name: nodejs-deployment
  namespace: nodejs
  labels:
   app: nodejs-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nodejs-app
  template:
    metadata:
      labels:
        app: nodejs-app
    spec:
      containers:
        - name: nodejs-app
          image: lucky0111/nodejs:latest
          ports:
            - containerPort: 3000

Namespace Configuration

Next, I created a file named namespace.yml:

kind: Namespace
apiVersion: v1
metadata:
  name: nodejs

Service Configuration

Finally, I created a file named service.yml:

kind: Service
apiVersion: v1
metadata:
  name: nodejs-service
  namespace: nodejs
spec:
  selector:
    app: nodejs-app
  ports:
    - protocol: TCP
      targetPort: 3000
      port: 3000

Applying Kubernetes Configurations

Now it was time to apply all the configurations to my Kubernetes cluster. I ran:

kubectl apply -f namespace.yml
kubectl apply -f deployment.yml
kubectl apply -f service.yml

I was relieved to see the output indicating that everything was created or unchanged:

deployment.apps/nodejs-deployment created
namespace/nodejs unchanged
service/nodejs-service unchanged

Step 8: Verifying the Deployment

To check if everything was running smoothly, I used:

kubectl get all -n nodejs

I was thrilled to see my pods running and the service created:

NAME                                    READY   STATUS    RESTARTS   AGE
pod/nodejs-deployment-f5b496ff7-9v89j   1/1     Running   0          49s
pod/nodejs-deployment-f5b496ff7-lqtnc   1/1     Running   0          49s
pod/nodejs-deployment-f5b496ff7-wcgdh   1/1     Running   0          49s

NAME                     TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
service/nodejs-service   ClusterIP   10.96.54.245   <none>        3000/TCP   115m

NAME                                READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/nodejs-deployment   3/3     3            3           50s

Step 9: Port Forwarding

To access my application, I needed to set up port forwarding. I ran:

kubectl port-forward service/nodejs-service -n nodejs 3000:3000 --address=0.0.0.0

I was happy to see the output confirming that the port was being forwarded:

Forwarding from 0.0.0.0:3000 -> 3000
Handling connection for 3000

Now, I could access my Node.js application by navigating to http://localhost:3000 in my web browser. It was such a rewarding moment to see my application up and running!

And there you have it! I successfully deployed my Node.js application using Docker and Kubernetes. This whole process taught me a lot about containerization and orchestration, and I hope my experience helps you on your journey too. If you have any questions or thoughts, feel free to drop them in the comments below.