Perrier

Perrier is a powerful JSON loader, which can use to load multi external JSON files, and merge to one JS object for large Node.js application uses.

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Quick Example

config/foo.json

{
    foo: 1
}

config/bar.json

{
    bar: 2
}

app.js

var config = require('perrier').create();
config.merge({
    './config/foo.json',
    './config/bar.json', 
    {
        baz: 3
    }
});

console.log(config); 

OUTPUT

{ 
    foo: 1, 
    bar: 2, 
    baz: 3 
}

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Why We Need This Tool

Manage Config Easily

• decompose large config file into multi config files
• combine different config files in different situations
• merge multi config file in one shot

Powerful JSON Format

• you can leave comment on JSON file
• you can add template string on JSON file, and replace automatically
• you can link other config file on JSON field, and load automatically

New Feature (added on v0.3.0)

• supported yaml format

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Usage

1. Powerful JSON

config/sample.json

{
    event: "archive",
    rule: /warn/,
    interval: 1000 * 60 * 10 // do it every 10 min
}

app.js

var config = require('perrier').create();
config.merge( './config/sample.json' );

console.log( config ) );

OUTPUT

{ 
    event: 'archive', 
    rule: /warn/, 
    interval: 60000
}

Supported comment / expression on JSON file.

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2. Template Replace

config/production.json

{
    // global is reserved CONFIG field, which will use to render template field on future merge
    global: {
        NODE_ENV: 'production',
        LOG_LEVEL: 'info'
    }
}

config/logger.json

{
    logger: {
        logPath: '/home/logs/{{NODE_ENV}}.log
        logLevel: '{{LOG_LEVEL}}+error'
    }
}

app.js

var config = require('perrier').create();
config.merge(
    './config/production.json',
    './config/logger.json'
);
console.log( config ) );

OUTPUT

{ 
    logger: {  
        logPath: '/home/logs/production.log', 
        logLevel: 'info+error' 
    }
}

The global field will be template source, if any other field contains {{key}}, it will be replaced with corresponding content.

So that you can change the first arg in different environment, but keep same log config file.

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3. Link to Other Config

config/main.json

{
    fooApp: 'conf: ./foo.json ', //link to external file
    barApp: {
        bar: true
    }
}

config/foo.json

{
    foo: true // which will be combined into main.json
}

app.js

var config = require('perrier').create();
config.merge( './config/main.json' );

console.log( config ) );

OUTPUT

{ 
    fooApp: { 
        foo: true 
    }, 
    barApp: { 
        bar: true 
    } 
}

If any fields start with conf:, then the engine will try to load an external file and replace here.

So that you can decompose large files into multi config files, and do the flexible combinations.

This feature also supports template render, you can add {{key}} in anywhere.

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4. Runtime Config

config/main.json

{
    type: 'http',
    maxSocks: 5
}

app.js

var config = require('perrier').create();
config.merge(
    './config/main.json', 
    {
        maxSocks: 10
    }
);
console.log( config ) );

OUTPUT

{ 
    type: 'http', 
    maxSocks: 10 
}

You can load a static file, and overwrite with runtime config if you need.

Loader supports file path / plain object, all of those will be merged in sequentially.

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5. Monitor Method

app.js

function monitor(err, index, fileName) {
    console.log(arguments);
}

var config = require('perrier').create({
    monitor: monitor
});

config.merge({
    './config/a.json', 
    './config/b.json',
    monitor // latest arg can be monitor function
});

Engine will load config silently, but you can add a monitor function, it will be called once every config merged.

6. Supported YAML

All feature supported on yaml format, see example

( must install "js-yaml" manually )

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APIs

perrier.create( options )

• options.rootPath {String} - all config file will be resolved with root path. (default: process.cwd() )
• options.globalFields {Object} - default template source (optional)
• options.monitor {Function} - this fn will be called once every config merged

Example

// config/base.json
{
    server: '{{NODE_ENV}}
}

// app.js
var perrier = require('perrier');

var config = perrier.create({
    rootPath: path.join(__dirname, 'config'),
    globalFields: {
        NODE_ENV: process.env.NODE_ENV || 'development'
    }
});

config.merge('base.json'); // base.json will be converted to "__dirame/config/base.json""
console.log(config); // { server: 'development' }

init method, you can also call var Perrier = require('perrier'); new Perrier();

merge( source1, [, source2, ..., sourceN ])

See above usage, or example

getField( filedName )

return config.filedName or undefined

Example

config.getField('logger');

getGlobal()

return global fields ( the template source )

Example

config.getGlobal();

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Questions?

If you have any questions, feel free to create a new issue.