YAML

What is YAML?

YAML stands for “YAML Ain’t Markup Language”. It’s a data Serialization & Deserialization format often used for configuration files, data exchange, and pipeline scripting.

Basics

YAML uses indentation (spaces, not tabs) to define structure. It’s intuitive and often preferred over JSON or XML for its readability.

name: Penguin
likes:
  - Fish
  - Ice
  - Tux
is_cool: true

Key Features

Why use YAML?

YAML is clean, expressive, and supports complex data structures like lists, maps, and scalars.

• Scalars: Strings, numbers, booleans

• Sequences (lists):

  colors:
    - red
    - green
    - blue

• Mappings (dictionaries):

  environment:
    os: Linux
    shell: bash

Comments

# This is a comment
key: value  # Inline comment

Common Use Cases

• CD configuration (e.g., GitHub Actions, GitLab CI)
• Docker Compose files
• Kubernetes manifests
• Static site generator settings (e.g., Hugo)

Example: GitHub Actions Workflow

name: Build
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Run build
        run: make build

Warnings

Be careful!

YAML is sensitive to indentation and whitespace. Always use spaces, not tabs. Incorrect indentation leads to parsing errors.

Tools

• YAML linters: yamllint
• Online validators: yamlchecker.com

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Penguinified by https://chatgpt.com/g/g-683f4d44a4b881919df0a7714238daae-penguinify