Docker to Kubernetes Nginx Deployment Pipeline

Project Overview

This project demonstrates the complete containerization and deployment lifecycle of a web application using Docker and Kubernetes.

A custom Nginx web application was containerized using Docker, published to Docker Hub, and deployed on a Kubernetes multi-node cluster consisting of 1 Master Node and 3 Worker Nodes.

The project covers image creation, container deployment, image registry integration, Kubernetes deployment, service exposure, and application validation.

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Project Architecture

Custom HTML Application
          │
          ▼
      Dockerfile
          │
          ▼
    Docker Image
          │
          ▼
   Docker Container
          │
          ▼
     Docker Hub
          │
          ▼
 Kubernetes Deployment
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 Kubernetes Service
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          ▼
     Browser Access

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Environment

• Operating System: Ubuntu Linux
• Docker Engine
• Docker Hub
• Kubernetes Cluster
• kubeadm
• kubelet
• kubectl
• containerd
• Calico Networking

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Project Objectives

• Build a custom Docker image
• Deploy containers using Docker
• Push images to Docker Hub
• Pull images from a remote registry
• Deploy workloads on Kubernetes
• Scale applications using Deployments
• Expose applications using NodePort Services
• Validate end-to-end application accessibility

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Docker Implementation

Verify Docker Installation

docker --version

Create Dockerfile

FROM nginx:latest

COPY index.html /usr/share/nginx/html/index.html

EXPOSE 80

Build Docker Image

docker build -t asha-nginx:v1 .

Verify Images

docker images

Run Docker Container

docker run -d --name asha-web -p 8080:80 asha-nginx:v1

Verify Running Container

docker ps

Validate Application

http://192.168.247.129:8080

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Docker Hub Integration

Login to Docker Hub

docker login

Tag Image

docker tag asha-nginx:v1 asha21697/asha-nginx:v1

Push Image

docker push asha21697/asha-nginx:v1

Verify Repository

Image successfully published to Docker Hub and made available for Kubernetes deployments.

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Kubernetes Deployment

Create Deployment

kubectl create deployment asha-nginx \
--image=asha21697/asha-nginx:v1 \
--replicas=3

Verify Deployment

kubectl get deployment

Verify Pods

kubectl get pods -o wide

Expose Application

kubectl expose deployment asha-nginx \
--type=NodePort \
--port=80

Verify Service

kubectl get svc

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Commands Used

docker --version

docker build -t asha-nginx:v1 .

docker images

docker run -d --name asha-web -p 8080:80 asha-nginx:v1

docker ps

docker login

docker tag asha-nginx:v1 asha21697/asha-nginx:v1

docker push asha21697/asha-nginx:v1

kubectl create deployment asha-nginx \
--image=asha21697/asha-nginx:v1 \
--replicas=3

kubectl get deployment

kubectl get pods -o wide

kubectl expose deployment asha-nginx \
--type=NodePort \
--port=80

kubectl get svc

docker container prune -f

docker image prune -a -f

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Project Highlights

• Docker Containerization - Containerized a custom Nginx web application using Docker.
• Docker Image Management - Built and managed Docker images using Dockerfile.
• Docker Hub Integration - Published custom images to Docker Hub.
• Container Deployment - Executed and validated containers locally.
• Kubernetes Deployment - Deployed workloads on a Kubernetes multi-node cluster.
• Replica Management - Created Deployments with multiple replicas.
• Service Exposure - Exposed applications using NodePort Services.
• Application Validation - Verified end-to-end browser accessibility.
• Troubleshooting Experience - Resolved Docker authentication and deployment-related issues.
• Resource Optimization - Performed Docker image and container cleanup.
• DevOps Workflow - Demonstrated a complete Docker-to-Kubernetes deployment pipeline.

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Skills Demonstrated

• Docker Administration
• Docker Image Management
• Dockerfile Development
• Docker Hub Integration
• Container Lifecycle Management
• Kubernetes Deployments
• Kubernetes Services
• Pod Management
• NodePort Networking
• Linux Administration
• DevOps Fundamentals
• Container Orchestration
• Application Deployment
• Infrastructure Troubleshooting

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Screenshots

Docker Installation Verification

Docker Image Build

Docker Images

Running Docker Container

Docker Hub Push

Kubernetes Deployment

Running Pods

Kubernetes Service

Application Output

Docker Cleanup

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Troubleshooting Experience

During the implementation of this project, several real-world issues were encountered and resolved:

Docker Permission Denied Error

• Encountered permission denied while accessing the Docker daemon socket.
• Resolved by executing Docker commands with appropriate privileges.
• Successfully validated Docker installation using the hello-world container.

Docker Hub Authentication Failure

• Initial Docker login attempts failed due to incorrect credentials.
• Verified Docker Hub account details and retried authentication.
• Successfully established Docker Hub access.

Docker Image Tagging and Repository Management

• Local Docker images were not accessible to Kubernetes worker nodes.
• Tagged images using Docker Hub repository conventions.
• Published images successfully to a centralized registry.

Kubernetes Image Pull Validation

• Verified successful image retrieval from Docker Hub.
• Ensured image availability across all worker nodes.
• Confirmed container startup after image download.

Pod Initialization Monitoring

• Observed pods in ContainerCreating state during deployment.
• Monitored pod lifecycle and image pull progress.
• Verified successful transition to Running state.

Service Exposure and Accessibility

• Configured Kubernetes NodePort Service.
• Verified service creation and port assignment.
• Successfully accessed the application through the browser.

Docker Resource Cleanup

• Performed container and image cleanup using Docker prune commands.
• Reclaimed storage space and optimized system resources.
• Verified cleanup using Docker system reports.

End-to-End Validation

Successfully verified:

• Docker Image Creation
• Docker Container Execution
• Docker Hub Image Publishing
• Kubernetes Deployment Creation
• Pod Scheduling Across Worker Nodes
• NodePort Service Accessibility
• Browser-Based Application Access

Key Learning Outcomes

• Understanding Docker image creation workflow
• Working with Docker containers and port mapping
• Publishing images to Docker Hub
• Integrating Docker Hub with Kubernetes
• Managing Deployments and ReplicaSets
• Exposing applications using Services
• Understanding container orchestration concepts
• Managing application lifecycle in Kubernetes
• Troubleshooting deployment issues
• Implementing real-world DevOps workflows

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Future Enhancements

• Jenkins CI/CD Pipeline
• Helm Package Management
• Prometheus Monitoring
• Grafana Dashboards
• Kubernetes Ingress Controller
• GitHub Actions Automation
• Horizontal Pod Autoscaling
• Kubernetes Persistent Volumes

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Author

ASHA

Linux | Docker | Kubernetes | DevOps Enthusiast