Xianjing_Huang_Mini_Proj_12

Requirements

• Create a simple python application containerized with a dockerfile.
• Demonstrate running your application within a docker container (using docker run terminal commands).
• Build a docker image in your CI/CD pipeline which will be pushed to Docker Hub or other container management service.

File Structure

├── .github/
│   └── workflows/
│       └── cicd.yml    # Define the GitHub Actions workflow for 
│                       # Checkout repository, Log in to Docker Hub, 
│                       # Build/Push Docker image
├── imgs/
├── .gitignore
├── app.py              # Main Python Flask application
├── Dockerfile          # Instructions for containerizing the app
├── Makefile            # Automation for Docker commands
├── README.md           # Project documentation
└── requirements.txt    # Python dependencies

Application Functionality

1. Users input their weight (in kilograms) and height (in centimeters).
2. The app calculates the BMI using the formula: BMI = weight / (height in meters)^2.
3. Displays the BMI and the corresponding category (Underweight, Normal, Overweight, or Obesity).

How It Works:

1. Access the application via a browser at http://127.0.0.1:5001.
2. Enter your weight and height, then submit the form.
3. The app calculates your BMI and displays it with the corresponding category.

Setup Instructions

1. Install Prerequisites

Ensure that Docker is installed on your system.

2. Clone the Repository

git clone https://github.com/nogibjj/Xianjing_Huang_Mini_Proj_12.git

3. Build the Docker Image

Use the make command to build the Docker image:

make build

4. Run the Docker Container

Run the Flask application in a Docker container:

make run

The application will be accessible at: http://127.0.0.1:5001.

Communication between the Host and the Container

1. Flask App:

   • Runs inside the container on port 5000 (--port=5000).
   • Listens on all network interfaces (--host=0.0.0.0).

   CMD ["flask", "run", "--host=0.0.0.0"]
   

   is the same as

   CMD ["flask", "run", "--host=0.0.0.0", "--port=5000"]
   

   since Flask runs on port 5000 by default.

   If your app needs to run on a different port, you can add --port=<port>.

2. Docker Networking:

   • Maps host machine's port 5001 to container's port 5000 (-p 5001:5000).

3. Access the App:

   • Open http://127.0.0.1:5001 in your browser to interact with the app running inside the container.

CI/CD Workflow for Deployment to Docker Hub

Set up the following secrets in your GitHub repository under Settings > Secrets and variables > Actions > Repository secrets

• DOCKER_USERNAME: Your Docker Hub username.
• DOCKER_PASSWORD: Your Docker Hub password or access token.

CI/CD steps:

1. Checkout repository
2. Log in to Docker Hub
3. Build Docker image
4. Push Docker image

Here is where you can see the container image pushed to DockerHub: