Sobre os arquivos YAML

Dados YAML

Lançado em 2001 Por Clark Evans, Ingy döt Net, Oren Ben-Kiki

Formato de serialização de dados legível humanamente (2001). Popular para configurações de aplicativos modernos (Docker, Kubernetes, Ansible, GitHub Actions). Mais legível que JSON.

Família

Documents & Text

Extensão

.yaml

Tipo MIME

application/x-yaml, text/yaml

Pode ser usado como

Entrada Saída

A história

COMO NASCEU O
FORMATO YAML.

2001

2009

YAML was proposed in 2001 by Clark Evans and refined with Ingy döt Net and Oren Ben-Kiki. The name originally meant "Yet Another Markup Language" but was quickly retconned to the recursive "YAML Ain’t Markup Language" to emphasize it was a data-serialization format, not a markup language like HTML. The design goal: a format that was easier for humans to read than JSON or XML, with support for comments, multi-line strings, references, and explicit types.

YAML found its killer app in configuration files. Ruby on Rails, Ansible, Kubernetes, Docker Compose, GitHub Actions, GitLab CI, and countless open-source projects use YAML for config. The downside: YAML’s permissive syntax has notorious gotchas — the infamous "Norway problem" where `country: NO` parses as boolean false, unquoted strings being auto-converted to timestamps, and indentation mistakes silently changing structure. YAML 1.2 (2009) fixed some of these; tools like strict-yaml and schemas help in production.

CURIOSIDADES E
FATOS INTERESSANTES.

YAML famously parses `country: NO` as boolean false — the "Norway problem" that ships in production config bugs regularly.

Kubernetes manifests, Docker Compose files, GitHub Actions workflows, and Ansible playbooks all run on YAML — billions of deployments per year.

The name was originally "Yet Another Markup Language" but changed to the recursive "YAML Ain't Markup Language" to clarify its purpose.

YAML supports references (&anchor and *alias) — you can define a block once and reuse it throughout the document.

The YAML 1.2 spec is 86 pages — most implementations only support a subset.

VANTAGENS E
LIMITAÇÕES.

Vantagens

Human-readable — the most legible config format in common use.
Comments supported (unlike JSON).
Multi-line strings, references, and anchors.
Adopted by every major DevOps tool.
Superset of JSON — valid JSON is valid YAML.

Limitações

Indentation-sensitive — a misplaced space can silently change meaning.
Implicit type coercion causes subtle bugs (NO → false, 22:00 → seconds, 1.0 → float).
Multiple inconsistent implementations across languages.
Parser CVEs appear regularly (YAML bombs, deserialization RCE).
Slower to parse than JSON.

Tamanhos típicos de arquivo

Small app config

1-5 KB

Typical Kubernetes manifest

5-50 KB

Large Ansible inventory

100 KB - 2 MB

Especificações técnicas

MIME type: application/yaml
Extensions: .yaml, .yml
Standard: YAML 1.2.2 (2021) / RFC draft ongoing
Encoding: UTF-8 (recommended) / UTF-16
Superset of: JSON

CONVERTER A PARTIR DE
YAML

yaml pdf yaml docx yaml odt yaml txt yaml md yaml html yaml epub yaml rst

Casos de uso comuns

DevOps configuration, Kubernetes manifests, CI/CD pipelines, Ansible playbooks