YAML

What is YAML?

YAML (YAML Ain't Markup Language) is a human-readable data serialization format. It's widely used for configuration files, CI/CD pipelines, Kubernetes manifests, and infrastructure as code due to its readability and ease of use.

YAML Syntax

Key-Value Pairs

name: John Doe
age: 30

Lists

fruits:
  - apple
  - banana
  - orange

Nested Objects

person:
  name: John
  address:
    city: New York
    zip: 10001

Multiline Strings

description: |
  This is a multiline
  string in YAML

Common Use Cases

Kubernetes

• Pod definitions
• Deployments
• ConfigMaps

CI/CD

• GitHub Actions
• GitLab CI
• CircleCI

Configuration

• Application config
• Docker Compose
• Ansible playbooks

Security Considerations

YAML Bombs Recursive aliases can cause DoS.

Arbitrary Code Execution Some parsers execute code in tags.

Injection User input in YAML can be dangerous.

Best Practices

• Use safe YAML parsers
• Validate YAML input
• Avoid loading untrusted YAML
• Lint configuration files
• Use schema validation
• Version control configs

Comparison