Corsyusha — Local CORS Proxy

Description

Simple and fast (built on top of fastify proxy to bypass CORS issues during prototyping against existing APIs without having to worry about CORS

This module was built to solve the issue of getting errors like this:

... has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

Installation

npm install -g corsyusha
# or
yarn global add corsyusha

Testing

yarn test:jest # Runs Jest with coverage collection
yarn test:coverage # Sends coverage to .coveralls.io
yarn test # yarn test:jest && yarn test:coverage

Usage

Let's imagine API endpoint that we want to request that has CORS issues:

https://licenseapi.herokuapp.com/licenses/mit

Start Proxy:

corsyusha --url https://licenseapi.herokuapp.com

Or:

CORSYUSHA_URL=https://licenseapi.herokuapp.com corsyusha

Or you may pull Docker image and run a container:

docker pull lordotu/corsyusha

docker run -dti \
  -e CORSYUSHA_URL=https://licenseapi.herokuapp.com \
  -e CORSYUSHA_HOST=0.0.0.0 \
  -p 8118:8118 \
  --name corsyusha \
  lordotu/corsyusha

Then in your client code, new API endpoint:

http://localhost:8118/proxy/licenses/mit

End result will be a request to https://licenseapi.herokuapp.com/licenses/mit without the CORS issues!

Alternatively you can install the package locally:

npm install corsyusha
# or
yarn add corsyusha

And add a script to your project:

 "scripts": {
   "proxy": "corsyusha --url https://licenseapi.herokuapp.com"
 }

Or:

 "scripts": {
   "proxy": "CORSYUSHA_URL=https://licenseapi.herokuapp.com corsyusha"
 }

Configuring

You may set params via command line args or via env variables. All defaults are stored in .env file in the root directory.

Only one argument is required: --url (or CORSYUSHA_URL if you prefer env variables).

Options

Option	Shorthand	Example	Default
--url	-u	https://licenseapi.herokuapp.com
--port	-p	8119	8118
--host	-h	0.0.0.0	localhost
--urlSection	-s	trhough	proxy
--serverLogging	-l	true	false
--headers		{"X-Requested-With": "Corsyusha"}	{}
--headers		{"X-Requested-With": "Corsyusha"}	{}
--origin	-o	http://127.0.0.1	*
--reflectOrigin	-r	true	false

Environment variables

Option	Example	Default
CORSYUSHA_URL	https://licenseapi.herokuapp.com
CORSYUSHA_PORT	8119	8118
CORSYUSHA_HOST	0.0.0.0	localhost
CORSYUSHA_URL_SECTION	trhough	proxy
CORSYUSHA_SERVER_LOGGING	true	false
CORSYUSHA_HEADERS	{"X-Requested-With": "Corsyusha"}	{}
CORSYUSHA_ORIGIN	http://127.0.0.1	*
CORSYUSHA_REFLECT_ORIGIN	true	false