Build-and-deploy-image-to-cluster

This guide walks you through building and deploying an application to your Kubernetes cluster, including sample outputs for verification.

Prerequisites

To follow this guide, you must:

• Install docker, the docker command-line tool
• Install kubectl, the Kubernetes command-line tool.

1. Build Your Container Image

1. Build the Image :

   docker build -t <registry-url>/<image-name>:<tag> .

Sample Output :

   Sending build context to Docker daemon   2.56MB
   Step 1/5 : FROM node:14
   ---> 4f1b1b8bdb1b
   Step 2/5 : WORKDIR /usr/src/app
   ---> Running in 54b0f3b74d5a
   Step 3/5 : COPY package*.json ./
   ---> c6161f4b5dcd
   ...
   Successfully built 12e4f23a1cb4
   Successfully tagged <registry-url>/<image-name>:<tag>

1. Push the Image :

   docker push <registry-url>/<image-name>:<tag>

Sample Output :

   The push refers to repository [<registry-url>/<image-name>]
   12e4f23a1cb4: Pushed
   abcdef123456: Pushed
   latest: digest: sha256:abcdef1234567890 size: 1573

2. Access Your Kubernetes Cluster

1. Verify the Cluster Info :

   kubectl cluster-info

Sample Output :

   Kubernetes control plane is running at https://123.45.67.89:6443
   CoreDNS is running at https://123.45.67.89:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

3. Create a Deployment Manifest

• Prepare a YAML file for your application’s deployment and service. deployment.yaml

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: my-app
    labels:
      app: my-app
  spec:
    replicas: 3
    selector:
      matchLabels:
        app: my-app
    template:
      metadata:
        labels:
          app: my-app
      spec:
        containers:
        - name: my-app-container
          image: <registry-url>/<your-image-name>:<tag>
          ports:
          - containerPort: 3000
  ---
  apiVersion: v1
  kind: Service
  metadata:
    name: my-app-service
  spec:
    selector:
      app: my-app
    ports:
      - protocol: TCP
        port: 80
        targetPort: 3000
    type: LoadBalancer

4. Apply the Manifest:

   kubectl apply -f deployment.yaml

Sample Output :

   deployment.apps/my-first-app created
   service/my-first-app-service created

5. Verify Deployment

1. Check Pods :

   kubectl get pods

Sample Output :

   NAME                           READY   STATUS    RESTARTS   AGE
   my-first-app-5b987c6bd7-abc12  1/1     Running   0          1m
   my-first-app-5b987c6bd7-def34  1/1     Running   0          1m

1. Monitor Logs :

   kubectl logs <pod-name>

Sample Output :

   Server running at http://0.0.0.0:8080

1. Check Services :

   kubectl get services

Sample Output :

   NAME                  TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
   my-first-app-service  LoadBalancer   10.96.56.23     123.45.67.89  80:30382/TCP   1m

6. Access Your Application

1. Verify Access with Curl :

   curl http://<external-ip>

Sample Output :

   Welcome to My First Kubernetes App!

7. Update Your Application

1. Update the Deployment :

   kubectl set image deployment/my-first-app my-first-app=<registry-url>/<new-image>:<new-tag>

Sample Output :

   deployment.apps/my-first-app image updated

1. Check Rollout Status :

   kubectl rollout status deployment/my-first-app

Sample Output :

   deployment "my-first-app" successfully rolled out

8. Clean Up Resources

1. Delete the Deployment and Service :

   kubectl delete -f deployment.yaml

Sample Output :

   deployment.apps "my-first-app" deleted
   service "my-first-app-service" deleted

1. Verify Cleanup :

   kubectl get all

Sample Output :

   No resources found in default namespace.

With these steps and outputs, you can confidently build, deploy, and verify your application in a Kubernetes cluster managed on Utho.