cf-options-builder

This is a builder for CloudFormation options objects, which get passed to calls to the createStack method of the official AWS CloudFormation api client. This handles all the complexity surrounding Parameter lists, as well as adding and removing Capabilities and setting standard properties.

For example:

var AWS = require('aws');
var Builder = require('cf-options-builder');

var options = new Builder({
  Parameters: [
    { ParameterKey: 'InstancesDesiredCapacity', ParameterValue: 2 }
  ],
  TemplateUrl: 'https://c3.amazonaws.com/some-cloudformation-templates/my-template.json'
});

options
  .set('StackName', 'my-stack-name')
  .setParameter('Environment', 'staging')
  .setParameter('InstanceType', 't3.medium')
  .setParameter('InstancesDesiredCapacity', 3)
  .setCapability('CAPABILITY_IAM')
;

// Here's what it looks like...
console.log(options.value());
/*
{
  Parameters: [
    {
      ParameterKey: 'Environment',
      ParameterValue: 'staging'
    },
    {
      ParameterKey: 'InstanceType',
      ParameterValue: 't3.medium'
    },
    {
      ParameterKey: 'InstancesDesiredCapacity',
      ParameterValue: 3
    }
  ],
  TemplateUrl: 'https://c3.amazonaws.com/some-cloudformation-templates/my-template.json',
  StackName: 'my-stack-name',
  Capabilities: [
    'CAPABILITY_IAM'
  ]
}
*/

// ...and this is how you use it with AWS
AWS.config.credentials = new AWS.SharedIniFileCredentials({ profile: 'my-profile' });

var cloudformation = new AWS.CloudFormation();

cloudformation.createStack(options.value(), function(err) {
  if (err) {
    throw err;
  }
});

Keep in mind that Parameters are specific to your CloudFormation template! The Parameters used in this example are plausible but your template may not have them!

API

var options = new OptionsBuilder(baseOptions);

Creates a new OptionsBuilder. Can optionally take in a base options object as a starting place for modification. Defaults to an empty object. Stores internally as a deep clone so that calls on the OptionsBuilder don't munge the original object.

options.value()

Returns a usable CloudFormation options object. Clones the internal state of the OptionsBuilder so that further calls to the OptionsBuilder don't munge the object.

options.set(key, value)

Sets a key on the object.

options.remove(key)

Sets a key on the object to undefined.

options.setCapability(value)

Adds the specified capability if not already set.

options.removeCapability(value)

Removes the specified capability if set.

options.setParameter(key, value)

Sets the parameter with 'key' to have 'value'. Takes care to modify any parameter with the existing key instead of blindly appending to the end.

options.removeParameter(key)

Removes the parameter with 'key', if it exists.

Tests

Tests use mocha. You can run them with:

$ npm test

License

MIT/X11.