modules

Container Base Modules

This directory contains modular components that extend the functionality of the base container image. Each module is designed to be self-contained, allowing for easy integration, management, and customization of various features without modifying the core container structure.

Overview

The modules system follows a plug-and-play architecture that enables:

Module Structure

Each module typically contains the following structure:

modules/
├── module_name/
│   ├── README.md                    # Documentation for the module
│   ├── module                       # Install script for the module
│   └── rootfs/                      # Root filesystem overlay
│       └── container/
│           └── base/
│               ├── defaults/        # Default configuration values
│               ├── functions/       # Shell functions for the module
│               └── scripts/         # Executable scripts

This structure follows the overlay pattern, where module files are copied on top of the base container filesystem during build time, extending the functionality without modifying the core files.

Using Modules

Enabling/Disabling Modules

Modules can be enabled or disabled using the IMAGE_MODULES environment variable or build argument:

IMAGE_MODULES="+module1,+module2,-module3"  # Enable module1, module2, disable module3

The + prefix enables a module, while the - prefix disables it.

Git-based Modules

Modules can also be installed from Git repositories using the following syntax:

IMAGE_MODULES="+git:https://git.repo/user/repo.git#v1.0.0"

This will clone the specified repository into /container/modules/repo and check out the specified tag or branch (in this case, v1.0.0).

Module Configuration

Each module can be configured using environment variables, typically prefixed with the module name (e.g., APP_ for the 'APP' module). See the README.md file in each module directory for specific configuration options.