YoshiHotta
3/18/2020 - 11:08 AM

jsonnet

#json #k8s #jsonnet

  • jsonnet -e <code>
  • jsonnet <file_name>

yaml に変換する

jsonnet -y <filename>

ファイルは配列でなければならない。例えば

// yaml_stream.jsonnet
local a = {
    x: 1,
    y: b.y,
  };
local b = {
    x: a.x,
    y: 2,
  };

[a, b]

これを jsonnet -y yaml_stream.jsonnet すると

---
{
   "x": 1,
   "y": 2
}
---
{
   "x": 1,
   "y": 2
}
...
/* A C-style comment. */
# A Python-style comment.
{
  cocktails: {
    // Ingredient quantities are in fl oz.
    'Tom Collins': {
      ingredients: [
        { kind: "Farmer's Gin", qty: 1.5 },
        { kind: 'Lemon', qty: 1 },
        { kind: 'Simple Syrup', qty: 0.5 },
        { kind: 'Soda', qty: 2 },
        { kind: 'Angostura', qty: 'dash' },
      ],
      garnish: 'Maraschino Cherry',
      served: 'Tall',
      description: |||
        The Tom Collins is essentially gin and
        lemonade.  The bitters add complexity.
      |||,
    },
    Manhattan: {
      ingredients: [
        { kind: 'Rye', qty: 2.5 },
        { kind: 'Sweet Red Vermouth', qty: 1 },
        { kind: 'Angostura', qty: 'dash' },
      ],
      garnish: 'Maraschino Cherry',
      served: 'Straight Up',
      description: @'A clear \ red drink.',
    },
  },
}
/*
- The local keyword defines a variable.
- Variables defined next to fields end with a comma (,).
- All other cases end with a semicolon (;).
*/

// A regular definition.
local house_rum = 'Banks Rum';

{
  // A definition next to fields.
  local pour = 1.5,

  Daiquiri: {
    ingredients: [
      { kind: house_rum, qty: pour },
      { kind: 'Lime', qty: 1 },
      { kind: 'Simple Syrup', qty: 0.5 },
    ],
    served: 'Straight Up',
  },
  Mojito: {
    ingredients: [
      {
        kind: 'Mint',
        action: 'muddle',
        qty: 6,
        unit: 'leaves',
      },
      { kind: house_rum, qty: pour },
      { kind: 'Lime', qty: 0.5 },
      { kind: 'Simple Syrup', qty: 0.5 },
      { kind: 'Soda', qty: 3 },
    ],
    garnish: 'Lime wedge',
    served: 'Over crushed ice',
  },
}
/*
- self refers to the current object.
- $ refers to the outer-most object.
- ['foo'] looks up a field.
- .f can be used if the field name is an identifier.
- [10] looks up an array element.
- Arbitrarily long paths are allowed.
- Array slices like arr[10:20:2] are allowed, like in Python.
- Strings can be looked up / sliced too, by unicode codepoint.
*/

{
  'Tom Collins': {
    ingredients: [
      { kind: "Farmer's Gin", qty: 1.5 },
      { kind: 'Lemon', qty: 1 },
      { kind: 'Simple Syrup', qty: 0.5 },
      { kind: 'Soda', qty: 2 },
      { kind: 'Angostura', qty: 'dash' },
    ],
    garnish: 'Maraschino Cherry',
    served: 'Tall',
  },
  Martini: {
    ingredients: [
      {
        // Use the same gin as the Tom Collins.
        kind:
          $['Tom Collins'].ingredients[0].kind,
        qty: 2,
      },
      { kind: 'Dry White Vermouth', qty: 1 },
    ],
    garnish: 'Olive',
    served: 'Straight Up',
  },
  // Create an alias.
  'Gin Martini': self.Martini,
  'Gin Fizz': self['Tom Collins']
}
{
  concat_array: [1, 2, 3] + [4],
  concat_string: '123' + 4,
  equality1: 1 == '1',
  equality2: [{}, { x: 3 - 1 }]
             == [{}, { x: 2 }],
  ex1: 1 + 2 * 3 / (4 + 5),
  // Bitwise operations first cast to int.
  ex2: self.ex1 | 3,
  // Modulo operator.
  ex3: self.ex1 % 2,
  // Boolean logic
  ex4: (4 > 3) && (1 <= 3) || false,
  // Mixing objects together
  obj: { a: 1, b: 2 } + { b: 3, c: 4 },
  // Test if a field is in an object
  obj_member: 'foo' in { foo: 1 },
  // String formatting
  str1: 'The value of self.ex2 is '
        + self.ex2 + '.',
  str2: 'The value of self.ex2 is %g.'
        % self.ex2,
  str3: 'ex1=%0.2f, ex2=%0.2f'
        % [self.ex1, self.ex2],
  // By passing self, we allow ex1 and ex2 to
  // be extracted internally.
  str4: 'ex1=%(ex1)0.2f, ex2=%(ex2)0.2f'
        % self,
  // Do textual templating of entire files:
  str5: |||
    ex1=%(ex1)0.2f
    ex2=%(ex2)0.2f
  ||| % self,
}
// Define a local function.
// Default arguments are like Python:
local my_function(x, y=10) = x + y;

local is_even(x) = 
  x % 2 == 0;


// Define a local multiline function.
local multiline_function(x) =
  // One can nest locals.
  local temp = x * 2;
  // Every local ends with a semi-colon.
  [temp, temp + 1];

local object = {
  // A method
  my_method(x): x * x,
};

{
  eight_is_even: is_even(8),
  // Functions are first class citizens.
  call_inline_function:
    (function(x) x * x)(5),

  call_multiline_function: multiline_function(4),

  // Using the variable fetches the function,
  // the parens call the function.
  call: my_function(2),

  // Like python, parameters can be named at
  // call time.
  named_params: my_function(x=2),
  // This allows changing their order
  named_params2: my_function(y=3, x=2),

  // object.my_method returns the function,
  // which is then called like any other.
  call_method1: object.my_method(3),

  standard_lib:
    std.join(' ', std.split('foo/bar', '/')),
  len: [
    std.length('hello'),
    std.length([1, 2, 3]),
  ],
}
/*
Conditional expressions look like if b then e else e. The else branch is optional and defaults to null.
*/

local Mojito(virgin=false, large=false) = {
  // A local next to fields ends with ','.
  local factor = if large then 2 else 1,
  // The ingredients are split into 3 arrays,
  // the middle one is either length 1 or 0.
  ingredients: [
    {
      kind: 'Mint',
      action: 'muddle',
      qty: 6 * factor,
      unit: 'leaves',
    },
  ] + (
    if virgin then [] else [
      { kind: 'Banks', qty: 1.5 * factor },
    ]
  ) + [
    { kind: 'Lime', qty: 0.5 * factor },
    { kind: 'Simple Syrup', qty: 0.5 * factor },
    { kind: 'Soda', qty: 3 * factor },
  ],
  // Returns null if not large.
  garnish: if large then 'Lime wedge',
  served: 'Over crushed ice',
};

{
  Mojito: Mojito(),
  'Virgin Mojito': Mojito(virgin=true),
  'Large Mojito': Mojito(large=true),
  'Large Virgin Mojeto': Mojito(large=true, virgin=true)
}
/* computed-field の中ではselfは使えない。  */

local Margarita(salted) = {
  ingredients: [
    { kind: 'Tequila Blanco', qty: 2 },
    { kind: 'Lime', qty: 1 },
    { kind: 'Cointreau', qty: 1 },
  ],
  [if salted then 'garnish']: 'Salt',
};
{
  Margarita: Margarita(true),
  'Margarita Unsalted': Margarita(false),
}
local arr = std.range(5, 8);
{
  array_comprehensions: {
    higher: [x + 3 for x in arr],
    lower: [x - 3 for x in arr],
    evens: [x for x in arr if x % 2 == 0],
    odds: [x for x in arr if x % 2 == 1],
    evens_and_odds: [
      '%d-%d' % [x, y]
      for x in arr
      if x % 2 == 0
      for y in arr
      if y % 2 == 1
    ],
  },
  object_comprehensions: {
    evens: {
      ['f' + x]: true
      for x in arr
      if x % 2 == 0
    },
    // Use object composition (+) to add in
    // static fields:
    mixture: {
      f: 1,
      g: 2,
    } + {
      [x]: 0
      for x in ['a', 'b', 'c']
    },
  },
}
/* 
- import するためのファイルは拡張子がlibsonnet
- importstr でテキストファイルをimportできる。
*/

local martinis = import 'martinis.libsonnet';

{
  hoge: importstr 'garnish.txt',
  'Vodka Martini': martinis['Vodka Martini'],
  Manhattan: {
    ingredients: [
      { kind: 'Rye', qty: 2.5 },
      { kind: 'Sweet Red Vermouth', qty: 1 },
      { kind: 'Angostura', qty: 'dash' },
    ],
    garnish: importstr 'garnish.txt',
    served: 'Straight Up',
  },
}
// Extend above example to sanity check input.
local equal_parts(size, ingredients) =
  local qty = size / std.length(ingredients);
  // Check a pre-condition
  if std.length(ingredients) == 0 then
    error 'Empty ingredients.'
  else [
    { kind: i, qty: qty }
    for i in ingredients
  ];

local subtract(a, b) =
  assert a > b : 'a must be bigger than b';
  a - b;

assert std.isFunction(subtract);

{
  test1: equal_parts(1, ['Whiskey']),
  test2: subtract(10, 3),
  object: {
    assert self.f < self.g : 'wat',
    f: 1,
    g: 2,
  },
  assert std.isObject(self.object),
}
/*
jsonnet --ext-str prefix="Happy Hour " \
        --ext-code brunch=true 
*/

local lib = import 'library-ext.libsonnet';
{
  [std.extVar('prefix') + 'Pina Colada']: {
    ingredients: [
      { kind: 'Rum', qty: 3 },
      { kind: 'Pineapple Juice', qty: 6 },
      { kind: 'Coconut Cream', qty: 2 },
      { kind: 'Ice', qty: 12 },
    ],
    garnish: 'Pineapple slice',
    served: 'Frozen',
  },

  [if std.extVar('brunch') then
    std.extVar('prefix') + 'Bloody Mary'
  ]: {
    ingredients: [
      { kind: 'Vodka', qty: 1.5 },
      { kind: 'Tomato Juice', qty: 3 },
      { kind: 'Lemon Juice', qty: 1.5 },
      { kind: 'Worcestershire', qty: 0.25 },
      { kind: 'Tobasco Sauce', qty: 0.15 },
    ],
    garnish: 'Celery salt & pepper',
    served: 'Tall',
  },

  [std.extVar('prefix') + 'Mimosa']:
    lib.Mimosa,
}
/*
jsonnet --tla-str prefix="Happy Hour" \
--tla-code brunch=true

tlaはfunction(){} と波括弧を使って利用することに注意。
*/

local lib = import 'library-tla.libsonnet';

// Here is the top-level function, note brunch
// now has a default value.
function(prefix, brunch=false) {

  [prefix + 'Pina Colada']: {
    ingredients: [
      { kind: 'Rum', qty: 3 },
      { kind: 'Pineapple Juice', qty: 6 },
      { kind: 'Coconut Cream', qty: 2 },
      { kind: 'Ice', qty: 12 },
    ],
    garnish: 'Pineapple slice',
    served: 'Frozen',
  },

  [if brunch then prefix + 'Bloody Mary']: {
    ingredients: [
      { kind: 'Vodka', qty: 1.5 },
      { kind: 'Tomato Juice', qty: 3 },
      { kind: 'Lemon Juice', qty: 1.5 },
      { kind: 'Worcestershire', qty: 0.25 },
      { kind: 'Tobasco Sauce', qty: 0.15 },
    ],
    garnish: 'Celery salt & pepper',
    served: 'Tall',
  },

  [prefix + 'Mimosa']: lib.Mimosa(brunch),
}
/* 継承は + で行う。つまりobjectのmergeと同じ。
Base + {... } と書いてもいいし、+ を省略して
Base {
  Derived
}
と書くこともできる。
*/

local Base = {
  f: 2,
  g: self.f + 100,
};

local WrapperBase = {
  Base: Base,
};



{ 
  Derived: Base + {
    f: 5,
    old_f: super.f,
    old_g: super.g,
  },
  WrapperDerived: WrapperBase + {
    Base+: { f: 4 },
  },
}