Documentation

z1/README.md

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+DOCKER APP DOCUMENTATION :
+AUTHOR : Somangsu MUkherjee
+
+1. Conditions for Deployment
+
+The application requires the following software:
+
+- Docker (version 20 or newer)
+- Docker Compose (v2 or integrated with Docker)
+- Bash shell (for .sh scripts) or PowerShell/CMD (Windows)
+- Internet connection (to download Docker images)
+
+2. Application Description
+
+This is a simple multi-container web application.
+
+The application allows users to:
+
+Enter their name in a web interface
+Submit the name to a backend server
+Store the name in a PostgreSQL database
+Retrieve and display all stored names
+
+The application demonstrates communication between multiple services using Docker.
+
+3. Virtual Networks and Volumes
+Virtual Network
+
+Docker Compose automatically creates a virtual network for communication between services.
+
+Services communicate using service names:
+
+Frontend communicates with backend (backend)
+Backend communicates with database (db)
+Named Volume
+pgdata is used for persistent database storage
+It is mounted to /var/lib/postgresql/data inside the PostgreSQL container
+This ensures that data is preserved even if containers are stopped or restarted
+
+4. Container Configuration
+Frontend
+Image: nginx:latest
+Port: 8080 (mapped to container port 80)
+Volume: ./frontend mounted to /usr/share/nginx/html
+Purpose: the frontend serves static HTML and JavaScript
+
+Backend
+Built from a custom Dockerfile (Node.js)
+Port: 3000
+Uses Express framework and also communicates with PostgreSQL database to send entered names to be stored
+
+Database (PostgreSQL)
+Image: postgres:15
+Internal port: 5432
+Environment variables:
+POSTGRES_USER=user
+POSTGRES_PASSWORD=password
+POSTGRES_DB=mydb
+the database uses named volume pgdata for persistence which makes sure that data is not lost even after stopping or removing the container.
+Uses init.sql for initial database setup
+
+Adminer
+Image: adminer
+Port: 8081
+Purpose: Web interface for managing the PostgreSQL database which stores all the data that is entered
+
+5. The table below describes all the containers utilised in this assignment
+| Container | Description                                  |
+| --------- | -------------------------------------------- |
+| frontend  | Nginx web server serving the frontend        |
+| backend   | Node.js server handling API requests         |
+| db        | PostgreSQL database storing application data |
+| adminer   | Web interface for managing the database      |
+
+
+6. Application Control
+
+Prepare Application:
+To prepare the application, the command ./prepare-app.sh is run in wsl which builds images and prepares the environment for execution.
+
+Start Application:
+./start-app.sh is run in the wsl command line to start all the 4 cointainers in detached mode.
+
+Stop Application
+to stop all the currently running containers without deleting data, ./stop-app.sh is run on wsl
+
+Remove Application
+./remove-app.sh stops all containers and removes volumes, networks, and all resources.
+
+7. Accessing the Application
+Main Web Application can be accessed on any browser locally running on http://localhost:8080
+
+The database Interface (Adminer) can be accessed similarly at http://localhost:8081
+
+Login credentials for Adminer are:
+
+System: PostgreSQL
+Server: db
+Username: user
+Password: password
+Database: mydb
+
+8. Used Resources
+Docker official documentation
+Docker Compose documentation
+Node.js documentation
+PostgreSQL documentation
+Nginx documentation
+
+9. Use of Artificial Intelligence
+
+Artificial intelligence tools such as chatGPT and Claude were used as a support tool during development for understanding docker concepts and debugging scripts. Some configuration issues were also fixed by referring to AI. All implementation, testing, and integration were performed independently.
+
+