Serverless CORS Plugin

A Serverless Plugin for the Serverless Framework which
adds support for CORS (Cross-origin resource sharing).


THIS PLUGIN REQUIRES SERVERLESS V0.5 OR HIGHER!

Introduction

This plugins does the following:

* It will add CORS response headers to all resource methods with a CORS-policy
configured.

* It will add an OPTIONS preflight endpoint with the proper headers for all
resources with a CORS-policy configured.

Installation

In your project root, run:

``bash
npm install --save serverless-cors-plugin
`

Add the plugin to s-project.json:

`json
"plugins": [
"serverless-cors-plugin"
]
`

To find the best compatible (major) version, use the table below:

Serverless version | Plugin version
---|:---
v0.1 | v0.1
v0.2-v0.3 | v0.2
v0.4 | v0.3
v0.5 | v0.4

Usage

Add the following properties to s-function.json to configure a CORS-policy:

`json
"custom": {
"cors": {
"allowOrigin": "*",
"allowHeaders": ["Content-Type", "X-Amz-Date", "Authorization", "X-Api-Key"]
}
}
`

The allowOrigin property is required, the other headers are optional. You can also add this
configuration to s-project.json instead of s-function.json to apply the CORS-policy
project-wide.

Run endpoint deploy and the CORS headers will dynamically be configured and deployed.
Use the -a / --all flag to deploy pre-flight OPTIONS endpoints.

*Caution: you will probably notice some warnings on missing stage and region
template variables. These can be ignored until the issue is fixed.*

Options

These are all options you can use:

Option | Type | Example
---|:---|:---
allowOrigin | String | "*"
allowHeaders | Array | ["Content-Type", "X-Api-Key"]
allowCredentials | Boolean | true
exposeHeaders | Array | ["Content-Type", "X-Api-Key"]
maxAge | Number | 3600`

For more information, read the CORS documentation.

Roadmap

* Dynamically set origin headers (#2)
* Add more verbose (debugging) output
* Better support for authenticated requests

License

ISC License. See the LICENSE file.