02 - Variables and System Facts

Learn how to define custom variables and use Mooncake's comprehensive system facts.

What You'll Learn

• Defining custom variables with vars
• Using all available system facts
• Combining custom variables with system facts
• Using variables in file operations

Quick Start

mooncake run --config config.yml

What It Does

1. Defines custom application variables
2. Displays all system facts (OS, hardware, network, software)
3. Creates files using both custom variables and system facts

Key Concepts

Custom Variables

Define your own variables:

- vars:
    app_name: MyApp
    version: "1.0.0"
    environment: development

Use them in commands and paths:

- shell: echo "Running {{app_name}} v{{version}}"

System Facts

Mooncake automatically collects system information:

Basic:

• os - Operating system (linux, darwin, windows)
• arch - Architecture (amd64, arm64)
• hostname - System hostname
• user_home - User's home directory

Hardware:

• cpu_cores - Number of CPU cores
• memory_total_mb - Total RAM in megabytes

Distribution:

• distribution - Distribution name (ubuntu, debian, macos, etc.)
• distribution_version - Full version (e.g., "22.04")
• distribution_major - Major version number

Software:

• package_manager - Detected package manager (apt, yum, brew, etc.)
• python_version - Installed Python version

Network:

• ip_addresses - Array of IP addresses
• ip_addresses_string - Comma-separated IP addresses

Variable Substitution

Variables work everywhere:

- file:
    path: "/tmp/{{app_name}}-{{version}}-{{os}}"
    state: directory

Seeing All Facts

Run mooncake facts to see all facts for your system:

mooncake facts

Next Steps

→ Continue to 03-files-and-directories to learn about file operations.