App Engine Proxy

App Engine Proxy is a Node.js proxy server that uses node-http-proxy to modify and proxy URL Fetch requests. This solution was inspired by an integration with a third party that requires a dedicated IP for their firewall.

Install

1. clone
2. cd app-engine-proxy
3. npm install
4. sudo nodejs app-engine-proxy.js

Daemonize and auto restart in case of process failure

1. npm install pm2
2. pm2 start app-engine-proxy.js
3. pm2 startup ubuntu
4. pm2 save

Usage

GET / HTTP/1.1
Host: proxy.example.com
X-Target: https://csgapi.appspot.com/v1/med_supp/open/companies.json
Cache-Control: no-cache

The main thing to notice here is the addition of the "X-Target" header. This is the URI you wish to reach. Optionally you may include the x-send-client-cert header with a value of true to send the certificates for client authentication.

CURL

curl https://csgapi.appspot.com/v1/med_supp/open/companies.json -x https://proxy.example.com/

Python (App Engine)

url = 'https://csgapi.appspot.com/v1/med_supp/open/companies.json'

headers = {
    'X-Target': url,
    'x-send-client-cert': true
}

response = urlfetch.fetch('https://proxy.example.com/', headers=headers)
print(response.status_code)
print(response.content)