Add Docker for Development and Production

[JacobGrisham]

[MADHUMITHASIVAKUMARR]

Adding Docker to your development and production workflows can greatly simplify the setup, deployment, and scaling of your finance full-stack web app. Here’s how to set up Docker for both environments.

Step 1: Install Docker

Make sure Docker is installed on your local development machine and on your production server. You can find installation instructions for various platforms on the Docker website.

Step 2: Create a Dockerfile

In your project root, create a Dockerfile. This file defines how your application is built and run.

Here's a basic example for a Flask app:

# Use the official Python image from the Docker Hub
FROM python:3.9-slim

# Set the working directory
WORKDIR /app

# Copy the requirements file
COPY requirements.txt .

# Install dependencies
RUN pip install --no-cache-dir -r requirements.txt

# Copy the application code
COPY . .

# Expose the application port
EXPOSE 5000

# Command to run the app
CMD ["flask", "run", "--host=0.0.0.0"]

Step 3: Create a .dockerignore File

Create a .dockerignore file to prevent unnecessary files from being copied into the Docker image. Here's a basic example:

__pycache__
*.pyc
*.pyo
*.pyd
.env
*.db

Step 4: Create a docker-compose.yml File

For both development and production, you can use docker-compose to manage multi-container applications. Here's a simple example:

version: '3.8'

services:
  web:
    build: .
    ports:
      - "5000:5000"
    volumes:
      - .:/app  # Mounts the current directory for development
    environment:
      FLASK_ENV: development

  db:
    image: postgres:13
    restart: always
    environment:
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password
      POSTGRES_DB: finance_db
    volumes:
      - db_data:/var/lib/postgresql/data

volumes:
  db_data:

Step 5: Build and Run Your Containers

For development, you can simply run:

docker-compose up

This command builds the Docker image and starts the containers. You should be able to access your Flask app at http://localhost:5000.

Step 6: Prepare for Production

For production, you may want to adjust your docker-compose.yml file to:

• Use a production-ready web server like Gunicorn.
• Remove the volume mount (or adjust it as necessary).
• Set environment variables for production configurations.

Example:

version: '3.8'

services:
  web:
    build: .
    ports:
      - "5000:5000"
    environment:
      FLASK_ENV: production
    command: ["gunicorn", "-b", "0.0.0.0:5000", "app:app"]  # Adjust app:app as needed

  db:
    image: postgres:13
    restart: always
    environment:
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password
      POSTGRES_DB: finance_db
    volumes:
      - db_data:/var/lib/postgresql/data

volumes:
  db_data:

Step 7: Deploy to Production

1. Build the production image:

   docker-compose build

2. Run the production containers:

   docker-compose up -d

Step 8: Manage Docker Containers

You can use the following commands to manage your Docker containers:

• Stop containers:

  docker-compose down

• View logs:

  docker-compose logs -f

Additional Considerations

• Networking: If your app has multiple services, you may want to set up a dedicated network in Docker.
• Environment Variables: Store sensitive information like database passwords using environment variables or Docker secrets.
• Monitoring: Consider adding monitoring solutions for your Docker containers in production.