Deploy Java-Based Tomcat Applications on Kubernetes: Step-by-Step Guide

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Ques:-

A new java-based application is ready to be deployed on a Kubernetes cluster. The development team had a meeting with the DevOps team to share the requirements and application scope. The team is ready to setup an application stack for it under their existing cluster. Below you can find the details for this:

Create a namespace named tomcat-namespace-datacenter.

Create a deployment for tomcat app which should be named as tomcat-deployment-datacenter under the same namespace you created. Replica count should be 1, the container should be named as tomcat-container-datacenter, its image should be gcr.io/kodekloud/centos-ssh-enabled:tomcat and its container port should be 8080.

Create a service for tomcat app which should be named as tomcat-service-datacenter under the same namespace you created. Service type should be NodePort and nodePort should be 32227.

You can use any labels as per your choice.

Ans:-

Here’s the complete Kubernetes YAML configuration to deploy your Java-based Tomcat application as per the provided requirements:

raj@jumphost ~$ cat pod.yaml 

---

apiVersion: v1

kind: Namespace

metadata:

  name: tomcat-namespace-datacenter

---

apiVersion: apps/v1

kind: Deployment

metadata:

  name: tomcat-deployment-datacenter

  namespace: tomcat-namespace-datacenter

  labels:

    app: tomcat

spec:

  replicas: 1

  selector:

    matchLabels:

      app: tomcat

  template:

    metadata:

      labels:

        app: tomcat

    spec:

      containers:

        - name: tomcat-container-datacenter

          image: gcr.io/kodekloud/centos-ssh-enabled:tomcat

          ports:

            - containerPort: 8080

---

apiVersion: v1

kind: Service

metadata:

  name: tomcat-service-datacenter

  namespace: tomcat-namespace-datacenter

spec:

  type: NodePort

  selector:

    app: tomcat

  ports:

    - port: 8080

      targetPort: 8080

      nodePort: 32227

raj@jumphost ~$ kubectl apply -f pod.yaml 

namespace/tomcat-namespace-datacenter created

deployment.apps/tomcat-deployment-datacenter created

service/tomcat-service-datacenter created

raj@jumphost ~$ kubectl get all -n tomcat-namespace-datacenter

NAME                                                READY   STATUS    RESTARTS   AGE

pod/tomcat-deployment-datacenter-6c696b4c7f-9qhdr   1/1     Running   0          36s

NAME                                TYPE       CLUSTER-IP    EXTERNAL-IP   PORT(S)          AGE

service/tomcat-service-datacenter   NodePort   10.96.33.73   <none>        8080:32227/TCP   36s

NAME                                           READY   UP-TO-DATE   AVAILABLE   AGE

deployment.apps/tomcat-deployment-datacenter   1/1     1            1           36s

NAME                                                      DESIRED   CURRENT   READY   AGE

replicaset.apps/tomcat-deployment-datacenter-6c696b4c7f   1         1         1       36s

raj@jumphost ~$ 


Then access the Tomcat app in your browser at:

http://<NodeIP>:32227

Replace <NodeIP> with your Kubernetes node's external IP.

Learn how to deploy a Java-based Tomcat application on a Kubernetes cluster using real-world DevOps practices. In this hands-on tutorial, you'll walk through the complete process of setting up a dedicated namespace, deploying a Tomcat container, and exposing it via a NodePort service.

What You’ll Learn:

• Creating and managing Kubernetes namespaces
• Deploying a Tomcat application using a custom Docker image
• Configuring Kubernetes Deployments and Services
• Exposing applications using NodePort
• Accessing the Tomcat web interface from your browser

This course is ideal for DevOps engineers, system administrators, and developers looking to gain practical experience in deploying Java applications on Kubernetes.