Docker Environments 🌍

Outline:

• [ ] Introduction to Multi-Environment Setup
• [ ] Why Use Multiple Environments?
• [ ] Creating Docker Compose Files for Each Environment
• [ ] Base Configuration 📝
• [ ] Production Setup ⚙️
• [ ] Development Setup 🛠️
• [ ] Switching Between Environments
• [ ] Best Practices for Managing Environments 🧑‍💻

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How to Run Docker with More than One Environment (Production and Development)?

1. Introduction to Multi-Environment Setup 🌟

When developing and deploying applications, it's crucial to maintain separate environments for development, testing, and production. This allows developers to experiment in development while ensuring stability in production.

2. Why Use Multiple Environments? 💡

• Development: Allows testing new features without affecting end users.
• Production: Stable environment optimized for performance and security.
• Staging/Testing: Optional environment to simulate production before deploying changes.

3. Creating Docker Compose Files for Each Environment 📂

Base Configuration (docker-compose.yml) 📄

This file contains the common configurations for your services. It can include shared services like databases.

version: "3"
services:
  app:
    image: myapp:latest
    environment:
      - APP_ENV=base
    networks:
      - mynetwork

  db:
    image: postgres:13
    environment:
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=pass
    networks:
      - mynetwork

networks:
  mynetwork:

Production Config (docker-compose.prod.yml) ⚙️

version: "3"
services:
  app:
    environment:
      - APP_ENV=production
    ports:
      - "80:80"
    restart: always
    logging:
      driver: "json-file"
      options:
        max-size: "10m"
        max-file: "3"
    networks:
      - mynetwork

networks:
  mynetwork:

Development Config (docker-compose.dev.yml) 🛠️

version: "3"
services:
  app:
    environment:
      - APP_ENV=development
    ports:
      - "8080:80"
    volumes:
      - .:/app
    command: npm run dev
    networks:
      - mynetwork

networks:
  mynetwork:

4. Switching Between Environments 🔀

You can easily switch between environments by combining the base file with the appropriate environment-specific file.

• Production:

docker-compose -f docker-compose.yml -f docker-compose.prod.yml up -d

• Development:

  docker-compose -f docker-compose.yml -f docker-compose.dev.yml up -d
  

These commands override the base configurations with environment-specific settings.

5. Practical Example 🧑‍💻

Here’s a scenario to show how you can switch between environments effectively:

Environment	Command	Description
Production	docker-compose -f docker-compose.yml -f docker-compose.prod.yml up -d	Runs the services with production settings. Ports are mapped to 80:80.
Development	docker-compose -f docker-compose.yml -f docker-compose.dev.yml up -d	Runs the services in development mode. Hot reloading and 8080:80 mapping.

6. Best Practices for Managing Environments 🛡️

1. Use .env files for secrets 🔑
   Store sensitive information such as database passwords in an .env file, which can be referenced in docker-compose.yml:

environment:
  - POSTGRES_USER=${POSTGRES_USER}
  - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}

1. Use Version Control for Docker Compose Files 📂
   Keep separate docker-compose files for each environment under version control so they can be reviewed and shared easily among teams.

2. Use a Staging Environment for Testing 📋
   Before deploying to production, consider running a staging environment using another Docker Compose file, such as docker-compose.staging.yml.

7. Visual Overview 🌐

Create a flowchart or diagram to illustrate how Docker uses different Compose files to configure environments. This could show the following steps:

• Docker uses docker-compose.yml as the base.
• It applies overrides from environment-specific files like docker-compose.prod.yml or docker-compose.dev.yml.
• The final container configuration is launched based on the merged setup.

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