Watson iOS SDK authentication - ios

Question

I've been looking at https://github.com/rfdickerson/watson-translation-demo which attempts to show how to do authentication using Facebook OAuth on iOS and with a NodeJS Backend.
The iOS code is straightforward :
let token: String = FBSDKAccessToken.currentAccessToken().tokenString
let fbAccess = FacebookAuthenticationStrategy(
tokenURL: "https://watsonsdkdemo.mybluemix.net/language-translation-service/api/v1/token",
fbToken: token)
translateService = LanguageTranslation(authStrategy: fbAccess)
The problem is that the server/app.js has
var creds = appEnv.getServiceCreds(/facebook-authentication/) || {}
and the manifest.yml has
- services:
- facebook-authentication
But when you cf push the scripts to your Bluemix account you get:
FAILED
Could not find service facebook-authentication to bind to xxxxxxx
The problem is nowhere does the author describe what the 'facebook-authentication" service is.
In the server deployment instructions they have
$ cf login
$ cf create-service speech_to_text standard speech-to-text-service
$ cf create-service text_to_speech standard text-to-speech-service
$ cf create-service language_translation standard language-translation-service
$ cf env
$ cd server
$ cf push
Nothing stating what the facebook-authentication service is.

Answer 1

I apologize that the instructions are incomplete. facebook-authentication is supposed to be a user-provided service. You can create it using the cf create-user-provided-service command:
cf create-user-provided-service facebook-authentication -p "APP_SECRET_GOES_HERE"
The idea is that when you register a Facebook application, they give you an App Secret. Since that secret should not be embedded in the source code, you can set it in the environment variables VCAP by creating a custom service that provides that information for you.
Note, I did not finish actually using the app secret to check the legitimacy of the credentials. Although this is a small security vulnerability for man-in-the-middle-attacks, the facebook token checking still works because in the Facebook App settings I made it so that using the App secret is not required. For now, just create the user service and set the value to anything you would like.
Hope this helps!