deploy-kubernetes-application

When to Use

When you need to deploy, scale, or manage containerized applications across multiple hosts using Kubernetes orchestration.

Prerequisites

• kubectl installed and configured
• Access to a Kubernetes cluster (local or cloud)
• Docker image of your application pushed to a registry
• Basic understanding of YAML syntax

Procedure

1. Create deployment YAML file: kubectl create deployment my-app --image=nginx --dry-run=client -o yaml > deployment.yaml
2. Apply the deployment: kubectl apply -f deployment.yaml
3. Expose the deployment as a service: kubectl expose deployment my-app --port=80 --target-port=80 --type=LoadBalancer
4. Check deployment status: kubectl get deployments
5. View running pods: kubectl get pods
6. Scale the application: kubectl scale deployment my-app --replicas=3
7. Check service details: kubectl get services

Verification

• Run kubectl get pods and confirm all pods show "Running" status
• Execute kubectl describe service my-app to verify service configuration
• Test application accessibility through service endpoint

Pitfalls

• Insufficient cluster resources can cause pods to remain in "Pending" state
• Image pull errors if the container registry is inaccessible
• Service type LoadBalancer may not work in local clusters without additional setup
• Resource limits not specified can lead to resource starvation

Sources

• https://kubernetes.io/
• https://en.wikipedia.org/wiki/Kubernetes
• https://www.redhat.com/en/topics/containers/what-is-kubernetes
• https://github.com/kubernetes/kubernetes
• https://cloud.google.com/learn/what-is-kubernetes