title: Secure Google Cloud Functions http trigger with auth
body: <p>I am trying out Google Cloud Functions today following this guide: <a href="https://cloud.google.com/functions/docs/quickstart" rel="noreferrer">https://cloud.google.com/functions/docs/quickstart</a></p>
  
  <p>I created a function with an HTTP trigger, and was able to perform a POST request to trigger a function to write to Datastore.</p>
  
  <p>I was wondering if there's a way I can secure this HTTP endpoint? Currently it seems that it will accept a request from anywhere/anyone. </p>
  
  <p>When googling around, I see most results talk about securing things with Firebase. However, I am not using the Firebase service here.</p>
  
  <p>Would my options be either let it open, and hope no one knows the URL endpoint (security by obscurity), or implement my own auth check in the function itself?</p>