Google AppEngine Request Proxy

Forward your HTTP requests through Google AppEngine (as proxy) while developing.

This will make you do local development for Google AppEngine (GAE) and connect to HTTPS endpoint without GAE throwing javax.net.ssl.SSLHandshakeException: Could not verify SSL certificate for: https://localhost:8080/1/oauth/request_token?locale=en .

The current GAE version 1.9.49 does not always HTTPS connections for non-Google owned servers, when you run a local instance of your GAE web application. There has been many issues 1 2 posted for Google to try to fix this.

But until Google fixes the issue, you can circumvent the problem by proxying your requests to a remote GAE instance, that then will forward your request to the right server - like in production.

Demo

Use http://gae-forward.appspot.com (or https) as proxe for your requests. Use the custom HTTP header X-domain to control which domain to forward your request too.

Example of POST request targeted https://your.domain.com/path/here using the proxy https://gae-forward.appspot.com/path/here

POST /path/here HTTP/1.1
Host: gae-forward.appspot.com
X-domain: https://your.domain.com
Cache-Control: no-cache

{"key":"123","value":"John Doe"}

Deploy

These instructions demonstrates how to deploy your own version application on Google App Engine.

See the Google App Engine standard environment documentation for more detailed instructions.

Setup

1. Update YOUR_PUBLIC_IP_HERE string in com.jleth.appengine.requestproxy.ForwardServlet to white-list your public IP address. Or you can disable white-listing completely by changing ALLOW_ONLY_WHITELISTED - beware that this is not advices, as bots may also make requests to your app
2. Update the <version>1.9.49</version> tag in pom.xml with the latest AppEngine SDK version.
3. Update the <application> tag in src/main/webapp/WEB-INF/appengine-web.xml with your project name.
4. Update the <version> tag in src/main/webapp/WEB-INF/appengine-web.xml with your version name.

Running locally

$ mvn appengine:devserver

Deploying

$ mvn appengine:update

Limitations

Right now this is a simple proxy, that only works for GET, POST and PUT requests.

License

Copyright 2017 Jeppe Leth

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.