YAML 是一种非常简洁/强大/专门用来写配置文件的语言！

YAML 语法特性

学过编程的人理解起来应该非常容易
语法特点

大小写敏感
通过缩进表示层级关系
禁止使用tab缩进，只能使用空格键
缩进的空格数目不重要，只要相同层级左对齐
使用#表示注释

# yaml
languages:
    - Ruby
    - Perl
    - Python
websites:
    YAML: yaml.org
    Ruby: ruby-lang.org
    Python: python.org
    Perl: use.perl.org

# Json
{
    languages: [
        'Ruby',
        'Perl',
        'Python'
    ],
    websites: {
        YAML: 'yaml.org',
        Ruby: 'ruby-lang.org',
        Python: 'python.org',
        Perl: 'use.perl.org'
    }
}

数据结构

对象: 键值对的字典
数组: 一组按次序排列的列表
纯量: 单个的且不可再分的值

# 纯量
hello

# 数组
- Cat
- Dog
- Goldfish

# 对象
animal: pets

引号区别

单引号(‘’): 特殊字符作为普通字符串处理
双引号(“”): 特殊字符作为本身想表示的意思

示例：

1 2	# 单引号 name: 'Hi,\nTom'

1 2	# 双引号 name: "Hi,\nTom"

内置类型列表

# YAML允许使用个感叹号(!)强制转换数据类型
# 单叹号通常是自定义类型，双叹号是内置类型
money: !!str
123

date: !Boolean
true

YAML 中的纯量

纯量是最基本的且不可再分的值

字符串

# 不使用引号
name: Tom

# 使用单引号
name: 'Tom'

# 使用双引号
name: "Tom"

布尔值

1 2	debug: true debug: false

数字

12       # 十进制整数
014      # 八进制整数
0xC      # 十六进制整数
13.4     # 浮点数
1.2e+34  # 指数
.inf     # 无穷大

Null

1 2	date: ~ date: null

时间

1 2	# 使用iso-8601标准表示日期 date: 2018-01-01t16:59:43.10-05:00

YAML 特殊类型

日常使用中基本不会用到的类型

文本块

注意”|”与文本之间须另起一行。使用|标注的文本内容缩进表示的块，可以保留块中已有的回车换行：

value: |
  hello
  world!

# 输出结果
# hello 换行 world

+表示保留文字块末尾的换行，-表示删除字符串末尾的换行：

value: |-
hello

value: |+
hello

# hello\n hello hello\n\n

注意”>”与文本之间的空格。使用>标注的文本内容缩进表示的块，将块中回车替换为空格最终连接成一行：

1	value: > hello

hello 空格 world

锚点与引用

复制代码注意引用部分不能追加内容。使用&定义数据锚点，即要复制的数据。使用引用锚点数据，即数据的复制目的地：

name: &a yaml
book: *a

books:
   - java
   - *a
   - python

book： yaml
books：[java, yaml, python]

YAML 实例说明

光说不练假把式 => JS-Yaml 官网实例地址 https://nodeca.github.io/js-yaml

Collection Types

################################################################################

http://yaml.org/type/map.html ———————————————–#

map:

Unordered set of key: value pairs.

Block style: !!map
Clark: Evans
Ingy: döt Net
Oren: Ben-Kiki
Flow style: !!map { Clark: Evans, Ingy: döt Net, Oren: Ben-Kiki }

http://yaml.org/type/omap.html ———————————————-#

omap:

Explicitly typed ordered map (dictionary).

Bestiary: !!omap
- aardvark: African pig-like ant eater. Ugly.
- anteater: South-American ant eater. Two species.
- anaconda: South-American constrictor snake. Scaly.
# Etc.

Flow style

Numbers: !!omap [one: 1, two: 2, three: 3]

http://yaml.org/type/pairs.html ———————————————#

pairs:

Explicitly typed pairs.

Block tasks: !!pairs
- meeting: with team.
- meeting: with boss.
- break: lunch.
- meeting: with client.
Flow tasks: !!pairs [meeting: with team, meeting: with boss]

http://yaml.org/type/set.html ———————————————–#

set:

Explicitly typed set.

baseball players: !!set
? Mark McGwire
? Sammy Sosa
? Ken Griffey
baseball teams: !!set { Boston Red Sox, Detroit Tigers, New York Yankees }

http://yaml.org/type/seq.html ———————————————–#

seq:

Ordered sequence of nodes

Block style: !!seq
- Mercury # Rotates - no light/dark sides.
- Venus # Deadliest. Aptly named.
- Earth # Mostly dirt.
- Mars # Seems empty.
- Jupiter # The king.
- Saturn # Pretty.
- Uranus # Where the sun hardly shines.
- Neptune # Boring. No rings.
- Pluto # You call this a planet?
Flow style: !!seq [
Mercury,
Venus,
Earth,
Mars, # Rocks
Jupiter,
Saturn,
Uranus,
Neptune, # Gas
Pluto,
] # Overrated

Scalar Types

http://yaml.org/type/bool.html ———————————————-#

bool:

true
True
TRUE
false
False
FALSE

http://yaml.org/type/float.html ———————————————#

float:
canonical: 6.8523015e+5
exponentioal: 685.230_15e+03
fixed: 685_230.15
sexagesimal: 190:20:30.15
negative infinity: -.inf
not a number: .NaN

http://yaml.org/type/int.html ———————————————–#

int:
canonical: 685230
decimal: +685_230
octal: 02472256
hexadecimal: 0x_0A_74_AE
binary: 0b1010_0111_0100_1010_1110
sexagesimal: 190:20:30

http://yaml.org/type/merge.html ———————————————#

merge:

&CENTER { x: 1, y: 2 }
&LEFT { x: 0, y: 2 }
&BIG { r: 10 }
&SMALL { r: 1 }

All the following maps are equal:

Explicit keys
x: 1
y: 2
r: 10
label: nothing
Merge one map
<<: *CENTER
r: 10
label: center
Merge multiple maps
<<: [*CENTER, *BIG]
label: center/big
Override
<<: [*BIG, *LEFT, *SMALL]
x: 1
label: big/left/small

http://yaml.org/type/null.html ———————————————-#

null:

This mapping has four keys,

one has a value.

empty:
canonical: ~
english: null
~: null key

This sequence has five

entries, two have values.

sparse:
- ~
- 2nd entry
-
- 4th entry
- Null

http://yaml.org/type/str.html ———————————————–#

string: abcd

http://yaml.org/type/timestamp.html —————————————–#

timestamp:
canonical: 2001-12-15T02:59:43.1Z
valid iso8601: 2001-12-14t21:59:43.10-05:00
space separated: 2001-12-14 21:59:43.10 -5
no time zone (Z): 2001-12-15 2:59:43.10
date (00:00:00Z): 2002-12-14

JavaScript Specific Types

https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/RegExp

regexp:
simple: !!js/regexp foobar
modifiers: !!js/regexp /foobar/mi

https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/undefined

undefined: !!js/undefined ~

https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Function

function: !!js/function >
function foobar() {
return ‘Wow! JS-YAML Rocks!’;
}

Custom types

JS-YAML allows you to specify a custom YAML types for your structures.

This is a simple example of custom constructor defined in `js/demo.js` for

custom `!sexy` type:

var SexyYamlType = new jsyaml.Type(‘!sexy’, {

kind: ‘sequence’,

construct: function (data) {

return data.map(function (string) { return ‘sexy ‘ + string; });

}

});

var SEXY_SCHEMA = jsyaml.Schema.create([ SexyYamlType ]);

result = jsyaml.load(yourData, { schema: SEXY_SCHEMA });

foobar: !sexy

bunny
chocolate

本文标题： Kubernetes之YAML语法

发布时间： 2021年07月10日 00:00

最后更新： 2025年12月30日 08:54

原始链接： https://haoxiang.eu.org/793d1c91/

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