How to access local Cloud Endpoints API from mobile device

Question

I want to access my Cloud Endpoints API hosted on my local dev machine from an Android app running on a mobile device I use for testing.

My device can access my dev machine by IP address. I passed --host=192.1.168.101 to the App Engine launcher so that my local App Engine instance binds to the IP address. Although I can access the App Engine instance from 192.168.1.101, I get a 404 when my app makes an API call.

I noticed that going to http://192.168.1.101:9080/_ah/api/explorer/ does not show my API; it redirects to https://developers.google.com/apis-explorer/#p/. If I use http://localhost:9080/_ah/api/explorer/ I'm able to see my API as intended. It seems that using an IP address as the host is not working with Cloud Endpoints.

I'd rather not root my device to change its /etc/hosts file. Changing that might not be a solution anyway, since I'm unable to bind my App Engine instance to a hostname other than localhost.

This is my app.yaml config:

application: my-server
version: 1
runtime: python27
threadsafe: true
api_version: 1

handlers:
# Endpoints handler
- url: /_ah/spi/.*
  script: services.application

- url: /favicon\.ico
  static_files: favicon.ico
  upload: favicon\.ico

- url: .*
  script: main.app

Answer 1

You bound to your specific IP, but as a reminder, you can also bind to 0.0.0.0 (all available IPs). This is handy if you're using the maven appengine plugin and don't want to update the pom.xml file whenever your IP changes.

Next, make sure you're on the same network and can connect between the machines. I typically use ConnectBot to test by opening a telnet session to the IP address and port you defined for running locally. This will ensure your firewall isn't causing an issue.

Finally, update your code by adjusting the root url for your API. That would look something like this if your IP address were 192.168.1.100 and port were 8080:

Helloworld.Builder helloWorld = new Helloworld.Builder(AppConstants.HTTP_TRANSPORT,
    AppConstants.JSON_FACTORY, credential);
helloWorld.setRootUrl("http://192.168.1.100:8080/_ah/api/");

Answer 2

In your generated source code (usually the file named after your API name, such as Tictactoe.java), DEFAULT_ROOT_URL should be set to http://192.168.1.101:9080/_ah/api/. This URL isn't expected to provide anything useful if you load it in a browser. Rather, it's the base of the path to your API requests, e.g. http://192.168.1.101:9080/_ah/api/tictactoe/v1/board.

If you want to confirm your device is properly connecting to your local server (via your local network), load http://192.168.1.101:9080/_ah/api/explorer/ from the device browser.

Answer 3

The problem had nothing to do with the IP address. I needed to include a path in my API method decorator:

@endpoints.method(HelloRequest, HelloResponse, name='helloworld', path='test', http_method='GET')
    def helloworld(self, request):