cors-container

A CORS proxy in a container (Docker) for when you need to Access-Control-Allow-Origin: *!

You can use CORS Container without running it yourself via Heroku (it's on a free tier dyno, so initial startup time may be slow!) https://cors-container.herokuapp.com.

About

If you need permissive CORS for a front-end project, simply deploy this container and proxy your HTTP requests through it.

Once the container is running, you may navigate to http://container-address:3000/https://jacobclark.xyz, cors-container will then proxy the specified resource and transform the original headers to be CORS permissive, whilst keeping origional headers in-tact.

If you intend to use this in production over the open web, ensure the service is locked down with restrictive firewall/access permissions, otherwise any content may be proxied over your server.

I suggest implementing proper CORS headers on your resources and using this for development purposes only.

Relative URL rewriting

cors-container can rewrite relative URLs to full URLs of the response body you have proxied.

For example if we wish to proxy http://blog.jacobclark.xyz/ and cors-container is runinnng on http://localhost:3000/ the request URL would be http://localhost:3000/http://blog.jacobclark.xyz/.

cors-container will rewrite any relative URLs it finds in the proxies response body. For example <a href="/css/style.css"> would be modified to <a href="http://localhost:3000/http://blog.jacobclark.xyz/css/style.css"> in the proxied response.

This can be useful if you wish to be able to pull additional assets on a page through the proxy such as stylesheets and JavaScript.

This is not enabled by default as this option mutates the original response body.

Set rewrite-urls in the request header to cors-cotainer if you want relative URLs rewriting.

Deploying

Docker(hub)

$ docker pull imjacobclark/cors-container
$ docker run --restart=always -d -p 3000:3000 --name cors-container imjacobclark/cors-container

Docker(source)

$ git pull https://github.com/imjacobclark/cors-container.git && cd cors-container
$ docker build -t cors-container .
$ docker run --restart=always -d -p 3000:3000 --name cors-container cors-container

Node

$ git pull https://github.com/imjacobclark/cors-container.git && cd cors-container
$ npm run test && npm start

Thanks to

• Express
• request-promise
• rel-to-abs
• Supertest
• Mocha
• Nock