135 lines
3.6 KiB
Markdown
135 lines
3.6 KiB
Markdown
# KUBERNETES APP DOCUMENTATION
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## AUTHOR : Somangsu Mukherjee
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---
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**1. Conditions for Deployment**
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The application requires the following software:
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- Docker (version 20 or newer)
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- Kubernetes (Docker Desktop Kubernetes or Minikube)
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- kubectl (configured and working)
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- Bash shell (WSL recommended on Windows)
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- Internet connection (to download container images)
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---
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**2. Application Description**
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This is a Kubernetes-based multi-container web application.
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The application allows users to:
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- Enter their name in a web interface
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- Submit the name to a backend server
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- Store the name in a PostgreSQL database
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- Retrieve and display all stored names
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The application demonstrates communication and orchestration of multiple services using Kubernetes.
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---
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**3. Virtual Networks and Volumes**
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**Virtual Network**
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Kubernetes automatically manages networking between services and pods using internal DNS.
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Services communicate using service names:
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- Backend communicates with database (`db`)
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- External users access backend through NodePort service
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**Named Volume**
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Persistent storage is implemented using:
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- PersistentVolume (PV)
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- PersistentVolumeClaim (PVC)
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These are mounted to `/var/lib/postgresql/data` inside the PostgreSQL container
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This ensures that data is preserved even if pods are restarted or recreated
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---
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**4. Container Configuration**
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**Backend**
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- Image: `docker-app-backend:latest`
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- Port: `3000`
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- Built using Node.js and Express framework
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- Communicates with PostgreSQL database to store and retrieve names
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- Deployed using Kubernetes Deployment
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**Database (PostgreSQL)**
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- Image: `postgres:15`
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- Port: `5432`
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- Environment variables:
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- `POSTGRES_USER=user`
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- `POSTGRES_PASSWORD=password`
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- `POSTGRES_DB=mydb`
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The database uses PersistentVolume and PersistentVolumeClaim for persistence which ensures that data is not lost even after pod restarts
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Uses StatefulSet for stable identity and storage
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---
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**5. The table below describes all the components utilised in this assignment**
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| Component | Description |
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|--------------|--------------------------------------------------|
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| Namespace | Isolates all application resources |
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| Deployment | Runs Node.js backend application |
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| StatefulSet | Runs PostgreSQL database with persistent storage |
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| Service | Exposes backend externally using NodePort |
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| DB Service | Enables internal communication with database |
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---
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**6. Application Control**
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**Prepare Application:**
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To prepare the application, the backend image must be built using:
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```bash
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docker build -t docker-app-backend ./backend
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**Start Application:**
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Run the following command in WSL:
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./start-app.sh
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This creates all Kubernetes resources and starts the application
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Stop Application
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To stop the application:
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./stop-app.sh
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**Remove Application**
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Deleting the namespace removes all resources completely:
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kubectl delete namespace myapp
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**7. Accessing the Application**
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Backend API can be accessed at:
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http://localhost:30007
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Frontend can be accessed by opening:
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frontend/index.html
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**8. Used Resources**
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Kubernetes official documentation
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Docker documentation
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Node.js documentation
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PostgreSQL documentation
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9. Use of Artificial Intelligence
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Artificial intelligence tools were used as a support tool during development for understanding Kubernetes concepts and debugging deployment issues. Some configuration problems were resolved with AI assistance. All implementation, testing, and integration were performed independently. |