From d3869769f781530f9f0bb18a3a5e400aacf03911 Mon Sep 17 00:00:00 2001 From: medusa Date: Tue, 5 Aug 2025 22:15:16 -0500 Subject: [PATCH] Update tech_docs/docker_compose_guide.md --- tech_docs/docker_compose_guide.md | 103 +++++++++++++++++++++++++++++- 1 file changed, 100 insertions(+), 3 deletions(-) diff --git a/tech_docs/docker_compose_guide.md b/tech_docs/docker_compose_guide.md index 18dd4cb..e2e8120 100644 --- a/tech_docs/docker_compose_guide.md +++ b/tech_docs/docker_compose_guide.md @@ -1,5 +1,104 @@ # Deterministic Serendipity: A Comprehensive Guide to Mastering Docker Compose +--- + +I apologize for the confusion. Let's narrow the focus to the essential aspects of coding `docker-compose.yml` files, emphasizing the individual objects and systems design. We'll remove any lifecycle management (LCM) activities and concentrate solely on the configuration file itself. + +--- + +# Mastering Docker Compose: A Guide to Coding `docker-compose.yml` Files + +## Introduction +Docker Compose simplifies the process of defining and running multi-container Docker applications. This guide focuses on the essential components of the `docker-compose.yml` file, providing a clear understanding of how to structure and design your Docker Compose configurations. + +## Essential Components + +### Services +**Description**: Services are the core objects in a `docker-compose.yml` file, representing individual containers that make up your application. + +**Key Components**: +- **image**: Specifies the Docker image to use. +- **build**: Specifies the build context for a Dockerfile. +- **ports**: Maps container ports to host ports. +- **environment**: Sets environment variables. +- **volumes**: Mounts volumes or bind mounts. +- **depends_on**: Defines startup dependencies. +- **healthcheck**: Defines health check commands. +- **user**: Specifies the user to run the container as. + +**Pseudocode**: +```plaintext +services: + web: + image: "node:20" + ports: ["5000:5000"] + environment: ["NODE_ENV=production", "DB_HOST=db"] + depends_on: ["db"] + volumes: [".:/app"] + user: "node" + + db: + image: "postgres:15" + volumes: ["db_data:/var/lib/postgresql/data"] + healthcheck: + test: ["CMD-SHELL", "pg_isready -U postgres"] + interval: "10s" + timeout: "5s" + retries: 5 +``` + +### Networks +**Description**: Networks define how services communicate with each other. + +**Key Components**: +- **name**: Specifies the network name. +- **driver**: Specifies the network driver (e.g., `bridge`). + +**Pseudocode**: +```plaintext +networks: + frontend: + backend: +``` + +### Volumes +**Description**: Volumes manage persistent storage for services. + +**Key Components**: +- **name**: Specifies the volume name. +- **driver**: Specifies the volume driver (e.g., `local`). + +**Pseudocode**: +```plaintext +volumes: + db_data: +``` + +## Systems Design Considerations + +### Modular Design +**Best Practice**: Each service should have a single responsibility to ensure clarity and maintainability. + +### Health Checks +**Best Practice**: Use health checks to ensure services are ready before starting dependent services. + +### Environment Variables +**Best Practice**: Use `.env` files to manage environment variables securely and avoid hardcoding sensitive information directly in the Compose file. + +### Non-Root Users +**Best Practice**: Run services as non-root users to enhance security. + +### Named Volumes +**Best Practice**: Use named volumes for persistent storage and bind mounts for development to share code between the host and container. + +### Custom Networks +**Best Practice**: Define custom networks to control how services communicate and use separate networks for different layers of your application (e.g., frontend and backend). + +## Conclusion +By focusing on the essential components and best practices outlined in this guide, you can ensure that your `docker-compose.yml` files are well-structured and logically designed. This approach will help you create configurations that are both predictable and flexible, making your Docker Compose setups more maintainable and scalable. + +--- + ## Introduction Docker Compose is a powerful tool for defining and running multi-container Docker applications. By treating everything as an object within the `docker-compose.yml` file, we can achieve deterministic serendipity—creating a configuration that is both predictable and flexible. This guide aims to provide a highly technical and dense overview of the various components, best practices, and pitfalls to avoid, ensuring you can achieve mastery over your Docker Compose files. @@ -267,6 +366,4 @@ services: ``` ## Conclusion -By treating everything as an object within your `docker-compose.yml` file and following the best practices outlined in this guide, you can achieve deterministic serendipity—creating a configuration that is both predictable and flexible. This guide provides a comprehensive overview of the key components, best practices, and pitfalls to avoid, ensuring you can master your Docker Compose files and achieve zen with your containerized applications. - -Thank you for your patience and understanding. I hope this guide helps you create expert-level Docker Compose files. \ No newline at end of file +By treating everything as an object within your `docker-compose.yml` file and following the best practices outlined in this guide, you can achieve deterministic serendipity—creating a configuration that is both predictable and flexible. This guide provides a comprehensive overview of the key components, best practices, and pitfalls to avoid, ensuring you can master your Docker Compose files and achieve zen with your containerized applications. \ No newline at end of file