Local Gruntfile.js which imports a common Gruntfile.js from a component.

GlobalGruntfile.js

//This is a normal Gruntfile with the exception of the deepExtend function added at the end
module.exports = function(grunt) {

  var port = grunt.option('port') || 8000;

  grunt.initConfig({
    //standard grunt config here
  });

  grunt.loadNpmTasks('grunt-cachepath');

  grunt.registerTask('default', ['build']);

  grunt.registerTask('build', function() {
    //...
  });
};

var _ = require('underscore');

module.exports.deepExtend = function(config1, config2) {
  _.each(config2, function(item, idx) {
    if (config1[idx] === undefined || _.isNumber(item) || _.isString(item) || _.isFunction(item) || !_.isObject(item)) {
      config1[idx] = item;
    }
    else {
      module.exports.deepExtend(config1[idx], item);
    }
  });
};

Gruntfile.js

var fs = require('fs');

var GLOBAL_FILENAME = './dev/components/gruntfile/GlobalGruntfile.js';

var global;
if (fs.existsSync(GLOBAL_FILENAME)) {
  global = require(GLOBAL_FILENAME);
}
else {
  console.error('Global Gruntfile.js not found. Did you install the gruntfile component?');
  process.exit(1);
}

module.exports = function(grunt) {
  global(grunt);

  var globalConfig = grunt.config.getRaw() || {};

  //optionally define globalConfig overrides here
  //this example overrides the port and hostname settings on connect:serve (it is equivalent to the method used below)
  var localConfig = {
    connect: {
      serve: {
        options: {
          port: 8002,
          hostname: '0.0.0.0'
        }
      }
    }
  };
  global.deepExtend(globalConfig, localConfig);

  //optionally make edits to the config here instead of putting them in localConfig
  //this example overrides the port and hostname settings on connect:serve
  globalConfig.connect.serve.options.port = 8002;
  globalConfig.connect.serve.options.hostname = '0.0.0.0';


  //give grunt the new config
  grunt.initConfig(globalConfig);


  //optionally register any custom tasks
  grunt.registerTask('server', 'connect:serve');
};