Cloud Formation Templates

build.js

#!/usr/bin/env node

var fs = require('fs');
var path = require('path');
var hbs = require('handlebars');
var globals = JSON.parse(fs.readFileSync(__dirname+'/templates/common/globals.json'));

// Register Handlebars "helpers"
hbs.registerHelper('toLowerCase', function (str) { return str.toLowerCase(); });
hbs.registerHelper('toUpperCase', function (str) { return str.toUpperCase(); });
hbs.registerHelper('findAMI', function (ami, context) { return context.AMIs[ami]; });
hbs.registerHelper('ifIn', function (elem, list, options) {
  if(list.indexOf(elem) > -1) {
    return options.fn(this);
  }
  return options.inverse(this);
});
hbs.registerHelper('include', function (file, context, options) {
  var context = null == context ? args : context;
  var f = fs.readFileSync(file);
  return process_file(f, context);
});
hbs.registerHelper('lookupById', function (collection, id) {
  var collectionLength = collection.length;
  for (var i = 0; i < collectionLength; i++) {
      if (collection[i].Id === id) {
          return collection[i];
      }
  }
  return null;
});

// Compile a Handlebars template and run it
function process_file(tmpl, args) {
  var template = hbs.compile(tmpl.toString());
  var result = template(args);
  return result;
}

// Prepare the file system
fs.mkdir(__dirname+'/artifacts/cloudformation', function(err){});
process.chdir(__dirname+'/templates');

// Get all of the project files
fs.readdir('projects', function(err, files) {
  if(err) throw err;

  // Loop through each 'project' file
  files.forEach(function(file){

    // Only process handlebars templates
    if (path.extname(file) != '.hbs') return;

    // Process the file and build the final template
    fs.readFile('projects/' + file, {encoding: 'utf-8'}, function(err, tmpl){
        console.log('Processing ' + file);
        var context = JSON.parse(process_file(tmpl, globals));

        fs.readFile(context['Template'], {encoding: 'utf-8'}, function(err, tmpl2){
          // Combine the template context with the 'global' context
          var master={};
          for(var key in context) master[key]=context[key];
          for(var key in globals) master[key]=globals[key];

          // Build the final output and compute a file name
          var template = process_file(tmpl2, master);
          var output_name = (context['ProjectName'] + '.' + context['EnvType'] + '.template').toLowerCase();

          // Write out the CloudFormation template
          fs.writeFile(__dirname+'/artifacts/cloudformation/'+output_name, template, function(err){
            if (err) throw err;
          })
          // process.stdout.write(template);
        });
    });
  })
});