lulo-plugin-json-to-string

lulo JSON to String

lulo json-to-string is a plugin for lulo.

Returns a string representation of the provided JSON structure.

Installation

$ npm install lulo-plugin-json-to-string --save

Usage

Properties

• JSON: The original JSON structure. Required.
• TypeCast: Attempts to cast primitive types back to their original type. See more on type casting below.

Return Values

The resource will return a string representation of the provided JSON structure which can be accessed via "Fn::GetAtt".

Parameters

{ "Fn::GetAtt: ["ResourceName", "String"] }" Gives The JSON structure as a string

Required IAM Permissions

The Custom Resource Lambda requires no additional IAM Permissions.

License

The MIT License (MIT)

Change Log

Change Log

Type Casting

CloudFormation has a tendency to convert all properties to strings before giving them to a CustomResource.

In a nutshell this means that:

// Input
{
    "JSON": {
        "anInteger": 1
    }
}

// Becomes:
{
    "JSON": {
        "anInteger": "1"
    }
}

This oftentimes becomes a problem since a lot of AWS sdk calls does not accept "1" in place of 1 for an integer value.

If you provide the TypeCast property it will attempt to cast all primitives type back to their original type.

In other words:

'1' => 1
'1.1' => 1.1
'true' => true,
'false' => false

This works recursively as well as on arrays.

Note: The type casting is very eager and will cast anything it finds that matches a given regex (see src/index.js). There is no way to make exceptions from this.