serverless-plugin-extrinsic-functions

Introduces additional Fn:: functions such as Fn::StartsWith.

Install

Run npm install in your Serverless project.

``yml
$ npm install --save-dev serverless-plugin-extrinsic-functions
`

Add the plugin to your serverless.yml file

`yml
plugins:
- serverless-plugin-extrinsic-functions
`

How to use

This plugin lets you use a number of custom Fn:: functions in the serverless.yml file. For example, you can use it as part of CloudFormation Conditions:

`yml
resources:
Conditions:
StartsWithDev:
Fn::StartsWith: [ "${opt:stage}", dev ]
`

You can also use it elsewhere in your serverless.yml as well, such as in the custom clause many plugins rely on, or as part of your function definitions:

`yml
functions:
hello:
handler: handler.hello
environment:
STARTS_WITH_DEV:
Fn::StartsWith: [ "${opt:stage}", dev ] # use in functions
`

These are the functions that are current supported, and the javascript functions they map to:

- Fn::StartsWith: ([ input, prefix ]) => input.startsWith(prefix)
- Fn::EndsWith: ([ input, suffix ]) => input.endsWith(suffix)
- Fn::Substr: ([ input, from, length ]) => input.substr(from, length)
- Fn::Substring: ([ input, start, end ]) => input.substring(start, end)
- Fn::RandomNumber: ([ min, max ]) => Math.random() * (max - min) + min
- Fn::GreaterThan: ([ x, y ]) => x > y
- Fn::LessThan: ([ x, y ]) => x < y
- Fn::Max: ([ x, y ]) => Math.max(x, y)
- Fn::Min: ([ x, y ]) => Math.min(x, y)
- Fn::JsonPath: ([ json, path ]) => lodash.get(JSON.parse(json), path)`