YAML 格式化

一、YAML 适合写什么

YAML 的设计目标只有一个：让人读得下去。它用缩进表达层级、用短横线表达列表，几乎没有括号和引号，所以特别适合人来手写的场景——Kubernetes 清单、CI 流水线定义、Ansible 剧本、Docker Compose、静态站点配置，基本都是 YAML。

代价是：它对格式极其敏感。少一个空格、多一个 Tab，含义就变了，甚至直接报错。

二、三条必须记住的规则

• 只能用空格缩进，不能用 Tab。YAML 规范明确禁止制表符。从编辑器里复制过来的内容如果混了 Tab，报错往往指向一个看起来完全正常的行——这是最难查的一类问题。
• 同一层级缩进必须完全一致。有的人写 2 个空格，有的人写 4 个，混在一起就会把同级的两个键变成父子关系。
• 冒号后面要有一个空格。name:JiangYu 不是一个键值对，而是一个字符串 "name:JiangYu"。

三、怎么用

1. 粘贴 YAML，点「格式化」，工具会统一缩进并检查语法；
2. 如果报错，按提示的行号去看那个位置——通常是缩进异常或缺少冒号后的空格；
3. 需要给程序消费时，点「转为 JSON」，得到带引号的标准结构；
4. 把结果复制回编辑器。

四、类型推断带来的意外

YAML 会自动猜类型，这在配置里是个双刃剑：

你写的	可能被读成	怎么避免
1.20	数字 1.2	加引号 "1.20"
0755	八进制 493	加引号 "0755"
on / no	布尔值（部分解析器）	加引号
2026-10-24	日期对象	加引号

这也是"配置文件在本地没问题，部署到服务器就报错"的常见原因：两边用的解析器版本不同，类型推断规则就不完全一样。凡是"看起来像数字/日期但其实要当字符串"的值，加引号最稳。

五、数据安全

解析完全在浏览器内完成，不会上传内容。但配置文件里经常含密码和令牌，用完建议清空输入框。

What YAML is good for

YAML has exactly one design goal: stay readable. Indentation carries the hierarchy, dashes mark lists, and there are almost no brackets or quotes, which makes it ideal for anything a human hand-edits: Kubernetes manifests, CI pipeline definitions, Ansible playbooks, Docker Compose, static site config.

The trade-off is fragility. One missing space or one stray tab changes the meaning, or fails outright.

Three rules worth memorising

• Spaces only, never tabs. The spec forbids tab characters. A tab pasted in from an editor produces an error on a line that looks perfectly fine — the hardest kind to find.
• Indentation must match exactly at the same level. Mixing two and four spaces silently turns sibling keys into a parent-child relationship.
• A colon needs a space after it. name:JiangYu is not a key/value pair; it is the string "name:JiangYu".

How to use it

1. Paste the YAML and press Format to normalise indentation and check the syntax;
2. If it errors, jump to the reported line — it is almost always indentation or a missing space after a colon;
3. Use Convert to JSON when a program will consume it;
4. Copy the result back into your editor.

When type inference bites

YAML guesses types automatically, which cuts both ways in configuration files:

You write	May be read as	How to avoid it
1.20	the number 1.2	quote it: "1.20"
0755	octal 493	quote it: "0755"
on / no	a boolean (in some parsers)	quote it
2026-10-24	a date object	quote it

This is also why a config that works locally can fail in production: the two sides run different parser versions with slightly different inference rules. If a value looks like a number or a date but must stay a string, quoting it is always the safe move.

Data safety

Parsing happens entirely in your browser. Config files often carry passwords and tokens, so clear the input when you are done.