Getting started with gofigure

• github
• webpage

gofigure is a configuration tool for node to help in the gathering and monitoring of configuration files in node.

Installation

npm install gofigure

or

git clone git@github.com:Pollenware/gofigure.git

Getting Started

• Loading A Configuration
  • Directories
  • Files
• Monitoring Property Changes
  • Monitoring All Files
  • Monitoring Certain Files
  • Property Topic Syntax
  • Property Change Callback
• Environments

Loading configurations

gofigure currently handles the loading of JSON files for configurations.

To Get an instance of a configuration object use the gofigure method. The gofigure method takes an object that accepts the following options

• locations : an array of directories that contain your configurations.
• files : an array of files that contain your configurations.
• monitor : set to true to monitor changes to configuration files.
• ignoreMissing : By default gofigure will ignore missing directories. Set this to false to prevent the ignoring of missing configuration directories.
• environment : By default will look for process.env.NODE_ENV if this is not set then gofigure will read all properties. If you wish to explicity set the environment then set this property.

var gofigure = require("gofigure");

//Loader for directory of configurations
var dirLoader = gofigure({
  locations : [__dirname + "/configs"]
});


//Loader for files of configurations
var dirLoader = gofigure({
  files : [process.env.HOME + "/configs/config1.json", __dirname + "/config1.json"]
});

You can load configurations asynchronously

loader.load(function(err, config){
    var PORT = config.port, HOST = config.host;
});

or synchronously

var gofigure = require("gofigure");

var loader = gofigure({locations : [__dirname + "/configs"]});
var config = loader.loadSync();

Directories of configurations

To load directories that contain configuration files in the options object provide locations property that is an array of directories than contain your configurations.

var gofigure = require("gofigure");

var loader = gofigure({locations : [__dirname + "/configs"]});
loader.load(function(err, config){
    var PORT = config.port, HOST = config.host;
});

The order of the locations matter as it defines a precedence for files. For example suppose you have a directory of default configuration files, and on production you want to override those configuration with environment specific configurations with out changing your module or source controlled files.

var gofigure = require("gofigure");

var loader = gofigure({locations : ["/prod/configs", __dirname + "/configs"]});
loader.load(function(err, config){
    var PORT = config.port, HOST = config.host;
});

Here any production configuration files found in /prod/configs will override the properties in __dirname + "/configs".

Another use case might be in development where you have default properties and instead of altering the source controlled files the developer can override them by putting them in their home directory.

var gofigure = require("gofigure");
var HOME = process.env.HOME;

var loader = gofigure({locations : [ HOME + "/yourApp/configs", __dirname + "/configs"]});
loader.load(function(err, config){
    var PORT = config.port, HOST = config.host;
});

Files

You may also load specific files rather than entire directories.

var gofigure = require("gofigure");

var loader = gofigure({files : ["/prod/configs/config1.json", __dirname + "/config.json"]});
loader.load(function(err, config){
    var PORT = config.port, HOST = config.host;
});

Again order matters /prod/configs/config1.json will override __dirname + "/config.json"

Monitoring

gofigure supports the monitoring of changes to configuration files.

All files

To enable monitoring you can specify monitor to true in the options.

var gofigure = require("gofigure");

var loader = gofigure({monitor : true, files : ["/prod/configs/config1.json", __dirname + "/config.json"]});
var config = loader.loadSync();

loading.on("my.cool.property", function(newValue){
  //...do something
});

Individual Files

To monitor certain files you can use the files property and with object that have a monitor : true KV pair.

var gofigure = require("gofigure");

var loader = gofigure({files : [
  { 
    file : "/prod/configs/config1.json", 
    monitor : true

  }, 
  __dirname + "/config.json"
]});
var config = loader.loadSync();

loading.on("my.cool.property", function(newValue){
  //...do something
});

Just config1.json will be monitored for changes.

Property topic syntax

To listen to all properties

loading.on(function(config){
  //...do something
});

loading.on(function(nameOfPropertyChanged, config){
  //...do something
});

loading.on(function(nameOfPropertyChanged, value, config){
  //...do something
});

To listen to specific properties

loading.on("my.cool.property", function(newValue){
  //...do something
});

loading.on("my.cool.property", function(newValue, config){
  //...do something
});

loading.on("my.cool.property", function(nameOfPropertyChanged, value, config){
  //...do something
});

Wild cards

//listen to any property changed on the my.cool object
loading.on("my.cool.*", function(propName, newValue){
  //...do something
});


//listen to the change of a property named 'property' on any object
//that is a member of my
loading.on("my.*.property", function(propName, newValue){
  //...do something
});

//listen to the change of a property named 'property' that is
//a member of a property called cool
loading.on("*.cool.property", function(propName, newValue){
  //...do something
});

//listen to the change of property or otherProperty on the my.cool object.
loading.on("my.cool.{property|otherProperty}", function(propName, newValue){
  //...do something
});

//listen to the change of property or otherProperty on the my cool or 
//notCool object.
loading.on("my.{cool|notCool}.{property|otherProperty}", function(propName, newValue){
  //...do something
});

Callback Arguments

The property change callback will pass in the following values depending on the arity of the callback.

If 1 argument is expected then just the callback invoked with the new value is a.

loading.on("my.cool.property", function(newValue){
  //...do something
});

If two arguments are expected then it is invoked with the property name and the new value.

loading.on("my.cool.property", function(propName, newValue){
  //...do something
});

Other wise the callback is invoked with the propertyName, newValue and the configuration object.

loading.on("my.cool.property", function(propName, newValue, configObject){
  //...do something
});

Environments

gofigure also supports environments, by default it will look for NODE_ENV and if it is set then it will use it.

The following is an example configuration file

{
    "development": {
        "logging":{
            "patio":{
                    "level":"DEBUG",
                    "appenders":[
                        {
                            "type":"RollingFileAppender",
                            "file":"/var/log/myApp/patio.log"
                        },                              
                        {
                            "type":"ConsoleAppender"
                        }
                    ]
                }
        },
        "app" : {
          "host" : "localhost",
          "port" : "8088"
        },
        "MYSQL_DB" : "mysql://test:testpass@localhost:3306/dev_db",
        "MONGO_DB" : "mongodb://test:testpass@localhost:27017/dev_db"
    },
    "production": {
        "logging":{
            "patio":{
                    "level":"ERROR",
                    "appenders":[
                        {
                            "type":"RollingFileAppender",
                            "file":"/var/log/myApp/patio.log"
                        }
                    ]
                }
        },
        "app" : {
          "host" : "prod.mydomain.com",
          "port" : "80"
        },
        "MYSQL_DB" : "mysql://test:testpass@prod.mydomain.com:3306/prod_db",
        "MONGO_DB" : "mongodb://test:testpass@prod.mydomain.com:27017/prd_db"        
    },
    "test": {
        "logging":{
            "patio":{
                    "level":"INFO",
                    "appenders":[
                        {
                            "type":"RollingFileAppender",
                            "file":"/var/log/myApp/patio.log"
                        }                                                       
                    ]
                }
        },
        "app" : {
          "host" : "test.mydomain.com",
          "port" : "80"
        },
        "MYSQL_DB" : "mysql://test:testpass@test.mydomain.com:3306/test_db",
        "MONGO_DB" : "mongodb://test:testpass@test.mydomain.com:27017/test_db"        
    }
}

To load just the development properties set the environment to development.

var gofigure = require("gofigure"),
    patio = require("patio"),
    mongoose = require("mongoose"),
    comb = require("comb"),
    DB, HOST, PORT;


var loader = gofigure({
  files : [__dirname + "/config-env.json"],
  environment : "development"
})
  .on("MYSQL_DB", function(uri){
    patio.connect(uri);
  })
  .on("MONGO_DB", function(uri){
    mongoose.connect(uri);
  })
  .on("logging", function(logging){
    new comb.logging.PropertyConfigurator().configure(logging);
    patio.configureLogging(logging);
  })
  .on("app", function(app){
    //...
  })
  .load(function(){
    //do something
  })

Wrap up

I hope this is useful is getting you started with gofigure and the potential uses of the library.

Please submit issues to github issues.

As always pull requests are welcome!