Built-In Helpers

Here are some of the built-in helpers available in the Lono DSL:

Method	Description
default_subnets	Returns Array of default Subnet Ids. Useful for config params.
default_vpc	Returns default VPC id. Useful for config params.
extract_scripts	Generates a script that can be included in user_data scripts to extract `scripts` files. More info about the helper is in the Extract Scripts docs.
key_pairs	Returns Array of Key Pairs. You can pass it a pattern to filter for keypairs. IE: `key_pairs(/default/).first`. Useful for config params.
stack_output	Returns the Stack output. IE: `stack_output("my-stack.OutputKey")`. Useful for params files.
stack_resource	Returns the Stack resource physical id. IE: `stack_resource("my-stack.LogicalId")`. Useful for params files.
tags	Converts a standard Ruby hash to the CloudFormation key, value structure.
user_data	Returns the script from the `app/user_data` folder as a String. Meant for user_data scripts.
user_data_script	Path location of the script to be used along with the `user_data_script` helper.

The built-in helpers are defined in this this source code file: dsl/evaluator/helpers.

You can also create your own helpers with Custom Helpers.