Kubernetes 之 YAML 語法

YAML 是一種很是簡潔/強大/專門用來寫配置文件的語言！html

YAML 全稱是」YAML Ain’t a Markup Language」的遞歸縮寫，該語言的設計參考了 JSON / XML 和 SDL 等語言,強調以數據爲中心，簡潔易讀，編寫簡單。java

YAML 語法特性

學過編程的人理解起來應該很是容易
node

語法特色python

大小寫敏感
經過縮進表示層級關係
禁止使用tab縮進，只能使用空格鍵
縮進的空格數目不重要，只要相同層級左對齊
使用#表示註釋

# 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'
    }
}

數據結構
-對象: 鍵值對的字典 -數組: 一組按次序排列的列表 -純量: 單個的且不可再分的值git

# 純量
hello

# 數組
- Cat
- Dog
- Goldfish

# 對象
animal: pets

引號區別github

單引號(''): 特殊字符做爲普通字符串處理
雙引號(""): 特殊字符做爲自己想表示的意思

# 單引號
name: 'Hi,\nTom'

# 雙引號
name: "Hi,\nTom"

內置類型列表web

# YAML容許使用個感嘆號(!)強制轉換數據類型
# 單歎號一般是自定義類型，雙歎號是內置類型
money: !!str
123

date: !Boolean
true

YAML 中的純量

純量是最基本的且不可再分的值編程

字符串數組

# 不適用引號
name: Tom

# 使用單引號
name: 'Tom'

# 使用雙引號
name: "Tom"

布爾值ruby

debug: true
debug: false

數字

12       # 十進制整數
014      # 八進制整數
0xC      ＃十六進制整數
13.4     ＃浮點數
1.2e+34  ＃指數
.inf     ＃無窮大

Null

date: ~
date: null

時間

# 使用iso-8601標準表示日期
date: 2018-01-01t16:59:43.10-05:00

YAML 特殊類型

平常使用中基本不會用到的類型

文本塊

# 注意「|」與文本之間須另起一行
# 使用|標註的文本內容縮進表示的塊，能夠保留塊中已有的回車換行
value: |
  hello
  world!

# 輸出結果
# hello 換行 world！

# +表示保留文字塊末尾的換行
# -表示刪除字符串末尾的換行
value: |
hello

value: |-
hello

value: |+
hello

# 輸出結果
# hello\n hello hello\n\n

# 注意「>」與文本之間的空格
# 使用>標註的文本內容縮進表示的塊，將塊中回車替換爲空格最終鏈接成一行
value: > hello
world!

# 輸出結果
# hello 空格 world！

錨點與引用

# 複製代碼注意*引用部分不能追加內容
# 使用&定義數據錨點，即要複製的數據
# 使用*引用錨點數據，即數據的複製目的地
name: &a yaml
book: *a
books:    - java    - *a
   - python

# 輸出結果
book： yaml
books：[java, yaml, python]

YAML 實例說明

光說不練假把式 => JS-Yaml 官網實例地址 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
  # Flow style
  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